Updates in Continuous Spinal Anesthesia - Cairo...

Updates in Continuous Spinal Anesthesia

Essay

Submitted for the partial fulfillment of Master degree in anesthesiology

By

Eslam Ayman Mohamed Shawki Kahla

(M.B.B.CH,)

Under the supervision of

Prof. Dr. Maher Fawzy Mahmoud Professor of Anesthesiology

Faculty of Medicine

Cairo University

Ass. Prof. Dr. Ahmed Abd ElAziz Aref Assistant Professor of Anesthesiology

Faculty of Medicine

Cairo University

Dr. Maha Mohamed Ismail Lecturer of Anesthesiology

Faculty of Medicine

Cairo University

Faculty of Medicine

Cairo University

2010

Acknowledgement

Acknowledgement

I would like to express my sincere gratitude and profound thanks to Prof. Dr.

Maher Fawzy Mahmoud Professor of Anesthesiology, Faculty of Medicine, Cairo

University, for his valuable remarks and advices, constant encouragement, and his

meticulous supervision and outstanding support.

I'm also deeply indebted to Ass. Prof. Dr. Ahmed Abd ElAziz Aref,

Assistant Professor of Anesthesiology, Faculty of Medicine, Cairo University for

his sincere guidance and support to complete this work.

Also, I'm deeply grateful to Dr. Maha Mohamed Ismail, Lecturer of,

Anesthesiology, Faculty of Medicine, Cairo University, for her generous help,

valuable advices, great support and effort for this work.

I would like also to thank my parents, my wife and my brother for the

continuous help and support they offered me during this work. Lastly I like to

express my deepest gratitude to the oldest medical school in the Egypt, Kasr El Aini

which offered me all the learning and training chances I needed to become a

competent doctor who can give a hand of help to whoever needs it.

Index of Contents

I

Index of Contents

Content Page

Index of Contents ……………………………..……………………………………. I

Index of Figures ……………………………………...………………...…………. III

List of Abbreviations ……………...…………………………………………...….. V

Abstract ………………………………………………………………...………… VI

Introduction ……………………………………………………………………..…. 1

Chapter 1: Anatomy …………………………..…………………………..……….. 4

Chapter 2: History …………………………………………………………………. 7

Chapter 3: CSA Kits, Drugs and Related Devices …………………………….…. 12

- The Most Commonly Used CSA Kits …………………………………………… 12

- Drug Agents That Can Be Used Intrathecally …………………………………… 16

- Implantable Intrathecal Drug Delivery Systems (Pumps) ……………………..… 22

Chapter 4: Indications & Advantages of CSA ……………………………...…….. 26 I- Obstetric and Gynecological Procedures ……………………………………….. 28

II- Surgeries in the Lower Part of the Body with or without Coexisting Disease .... 34

III- Pediatric Open Heart Surgery …………………………………………………. 40

- General Advantages of Neuraxial Blocks ……………….………………...…….. 42

Chapter 5: Contraindications & Complications …………………………...……… 43 - Contraindications for Continuous Spinal Anesthesia …………………….……… 43

- Complications of Continuous Spinal Anesthesia …………………………….…….... 47

(A) General Complications …………………………………………………… 48

(B) Catheter-Related Complications …………………………………..……… 60

Index of Contents

II

Conclusion ………………………………………………….…………………….. 70

Summary ………………………………………………………………..………… 71

References …………………………………………………………………..……. 73

Index of Figures

III

Index of Figures

Figure Number Figure Description Reference Page

01 A lumbar vertebra in lateral and antero-superior views. 5 4 02 The lumbar interlaminar gap. 5 4 03 The anatomy of lumbar puncture. 5 5 04 Midsagittal view of the meninges, ventricles, subarachnoid spaces,

and cisternae. 5 5 05 Lemmon needle. 12 7 06 The Patient lying with the CSA needle protruding from his back 12 7 07 Hingson Ferguson needle. 12 8 08 Tuohy needle. 12 8 09 Tuohy Flowers needle. 12 8 10 Cappe and Deutsch needle. 12 8 11 CSA needle with Protective Shield over Lumbar spine. 12 9 12 CSA needle metal protector. 12 9 13 Spinocath® catheter over needle Kit. www.bbraun.com 12 14 27G Quincke spinal needle with braided wire attached to it and

catheter over both of them. www.bbraun.com 12 15 Passing the spinal needle through the dura. www.bbraun.com 13 16 Pulling on the wire to remove the needle from within the catheter. www.bbraun.com 13 17 Conventional catheter through needle design with CSF leaking from

around the catheter. www.bbraun.com 14

18 Spinocath® catheter over the needle design with the catheter sealing the dural puncture causing minimal CSF leak. www.bbraun.com 14

19 Portex® Catheter through needle kit. www.smiths-medical.com 15

20 Intrathecal drug delivery system: pump and catheter. 67 23

21 Lateral view showing the advantage of using an oblique approach to the spinal canal. The catheter can easily be advanced if a shallow angle is used.

67 23

22 Intrathecal pump and catheter assembly. 67 24

23 Scanning electron micrograph of a dural puncture hole made by a 25G Quincke (cutting) needle. View is from the inner (intrathecal) side of the Dura mater.

175 53

24 Scanning electron micrograph of a dural puncture hole made by a 25G Quincke (cutting) needle. View is from the outer (epidural) side of the Dura mater.

175 53

25 Scanning electron micrograph of a dural puncture hole made by a 25G Whitacre (non-cutting) needle. View is from the inner (intrathecal) side of the Dura mater.

175 54

26 Scanning electron micrographs of sterile catheters. 192 57

27 Scanning electron micrographs of sterile catheters. 192 58

28 Human lamina arachnoid. Scanning electron microscopy. Magnification 180X Bar: 100 µm. 198 61

Index of Figures

IV

29 Human spinal arachnoid trabecula. Trabecular arachnoid encircling motor and sensitive nerve roots at the entry site of nerve root cuffs. Scanning electron microscopy. Magnification 30X Bar: 1 µm.

198 61

30 Human spinal arachnoid trabecula encircling the spinal cord. Scanning electron microscopy. Magnification 40X Bar: 100 µm. 198 62

31 Diagram of a likely cause of temporary and permanent neurological complications following CSA. 198 62

32 The needle passing the nerve. The indwelling catheter touching the anterior Dura and is starting to bend. 198 65

33 Looping of the catheter. This is inevitable when the distance inserted exceed 30 mm. 198 65

Index of Figures

V

List of Abbreviations - aPTT: Activated Partial Thromboplastin Time

- ASA: American society of anesthesiologists

- CES: Cauda Equina syndrome

- CNS: Central nervous system

- COPD: Chronic obstructive lung disease

- CPB: Cardiopulmonary bypass

- CSA: Continuous Spinal anesthesia

- CSA/A: Continuous Spinal anesthesia/analgesia

- CSE: Combined Spinal-Epidural

- CSF: CerebroSpinal fluid

- DVT: Deep vein thrombosis

- FDA: Federal Drug Administration

- GABAB: Gamma Aminobutyric acid receptor type B

- GABA: Gamma Aminobutyric Acid

- G: Gauge

- IL: Interleukin

- IT: Intrathecal

- IONV: Intraoperative nausea and vomiting

- LMWHs: Low moelcular weight heparins

- MLAD: Minimum effective local anesthetic dose

- NMDA: N-methyl-D-aspartate

- PCA: Patient controlled analgesia

- PDPH: Post Dural Puncture Headache

- SSSA: Single-shot Spinal anesthesia

- UFH: Un-Fractionated Heparin

Abstract

VI

Abstract

Continuous Spinal anesthesia (CSA) as a technique evolved since Augustus

Bier described the first Spinal anesthetic with Cocaine in 1899, and in 1906 Henry

Percy Dean invented the "exploring needle" which can be left in situ during the

operation so that at any moment another dose can be injected. CSA has marked

advantages in certain clinical circumstances, particularly patients undergoing lower

body surgery who are old and/or have co-morbidities, they can benefit from

avoiding the risks of endotracheal intubation and general anesthesia and in the same

time avoiding rough hemodynamic changes associated with other types of neuraxial

blocks without losing their advantages. Also the intrathecal catheter can be used for

post-operative analgesia and for long term intrathecal drug administration to control

chronic pain or spasticity. There are many types of intrathecal catheters that can be

used with different techniques of insertion, advantages and disadvanatages. Also

there are possible complications to the technique which must be understood and

managed, and contraindications with which the technique should be avoided or

modified.

Keywords: Continuous Spinal anesthesia, neuraxial anesthesia, neuraxial

blocks, high risk patients, intrathecal catheter, continuous analgesia, post-operative

analgesia, chronic pain management, intrathecal pumps.

Introduction

Introduction

1

Introduction

Continuous Spinal anesthesia (CSA) is the technique of producing and

maintaining Spinal anesthesia with small doses of local anesthetic which are

injected repeatedly as required into the Subarachnoid space via an indwelling

catheter.

Continuous Spinal anesthesia (CSA) as an alternative to general anesthesia for

many surgical procedures is a method almost as old as the technique of Spinal

anesthesia itself. Augustus Bier described the first Spinal anesthetic with Cocaine in

1899 and in 1906, Henry Percy Dean described a technique in which Spinal

anesthesia could be extended. Dean was aware that Ester local anesthetic agents did

not usually last long, that the dose requirement of local anesthetic agent varied in

each patient and that the duration of surgery could be different. To overcome this,

he considered giving another injection during the surgical procedure and he invented

the "exploring needle" which can be left in situ during the operation so that at any

moment another dose can be injected without moving the patient beyond a slight

degree. However, the technique did not become accepted into practice and his

efforts to promote it were probably limited due to his ill health and his retirement in

1933. [1]

CSA was rediscovered in 1940 and went through a "stuttering evolution"

through the 20th century by Tobias et al. who gave a fascinating account of this

technique. The CSA technique evolved further in the 1990s when Spinal micro-

catheters were introduced, but the technique was surrounded by controversy due to

assumed occurrence of Cauda-Equina syndrome leading to the banning of Spinal

micro-catheters by the Federal Drug Administration (FDA) in the USA. But Denny

questioned the etiology of Cauda-Equina syndrome and stated that "For a number of

years and on several occasions CSA has prevented patients from needing

postoperative ventilation and it would be unfortunate if this extremely useful

Introduction

2

technique was abandoned due to its inappropriate application". While in the same

time, CSA continued to be used in clinical practice outside of the USA. [2]

CSA has been used in medically complicated patients (as in patients with

respiratory failure) undergoing cardiac, vascular, orthopedic, and general surgeries.

Many authors advocate general anesthesia with or without Epidural analgesia as first

choice in fit patients undergoing abdominal procedures. While in selected patients

undergoing surgeries on the lower extremities, perineum, groin and lower abdomen,

who are living at the edge of their cardiovascular and respiratory physiological

reserves and in whom general anesthesia is likely to increase morbidity and

mortality, many authors advocate CSA as an alternative to general anesthesia. [2]

CSA allows conduction anesthesia to be tailored to individual patient needs

and also for surgical operations of long durations. The Spinal anesthesia is not more

dangerous than Epidural anesthesia, but when we combine the potential lack of

knowledge with the unforgiving Subarachnoid space and with the narrow

"therapeutic window" for Spinal local anesthetics, a background for significant

iatrogenic injury is set. It is with this in mind, as well as from the historical

perspective that the technique and its current applications are discussed. [3]

The best way to examine the clinical applications for CSA is by comparing it to

other available major conduction anesthetics: single-shot Spinal anesthesia,

continuous Epidural anesthesia and combined single-shot Spinal & continuous

Epidural anesthesia and also to general anesthesia. Catheters used for performing

CSA differ in sizes (gauge) and in technique of insertion:

1- Epidural catheter (macro-catheter):

A standard Epidural catheter can be used for continuous Spinal anesthesia

(standard Epidural catheters range from 18 to 20G). The catheter is inserted into the

subarachnoid space after a deliberate Dural puncture with an Epidural needle. These

Introduction

3

sets are widely available and little additional training is required for those familiar

with inserting a normal Epidural catheter. However, performing a deliberate Dural

puncture with an Epidural needle may be psychologically difficult for some

experienced clinicians, also Post Dural Puncture Headache (PDPH) is a risk as we

will see later. It should be put in mind that if this catheter type is left in situ for post

operative pain relief then there is potential for error, as an Epidural dose of drug

could be administered intrathecally. [3]

2- Catheter over-needle type:

Represented by the B Braun SPINOCATH®. Perceived advantages of this kit is

that CSF does not leak because the hole made in the Dura by the Spinal needle is

sealed by the wider bore catheter resulting in less incidence of PDPH, also there is

an unequivocal endpoint of catheter placement in the subarachnoid space because

CSF can be aspirated through the catheter. [4]

3- Catheter through-needle type:

These catheters are available in varying sizes ranging from 25G (macro-

catheter) to 32G (micro-catheter). Pajunk Intralong® manufactures 27G and 25G

catheters which are introduced through 22 or 21G Sprotte needles. Smith Medical®

produces the PORTEX® kit, a 28G micro-catheter with a 23G Crawford needle.

Kendal® produces a 28G micro-catheter with a 22G Sprotte needle. [4]

In this study we will try to discuss the commercially available CSA kits and

related devices, the advantages and indications of the CSA technique itself, its

limitations and complications.

Chapter 1 Anatomy

Chapter 1 Anatomy

4

1- The Lumbar Vertebrae:

The bodies of the Lumbar vertebrae are large and kidney-shaped (Fig.1), the

vertebral foramen is roughly triangular, larger than in the thoracic but smaller than

in the cervical region. The transverse processes are slender, they increase in length

from Ll to L3, then become shorter again so that the third transverse process is

longest. The Lumbar spines are horizontal and oblong. If the articulated vertebral

column is inspected from behind, it will be noted that the laminae and spines so

overlap and interdigitate with each other that the Spinal canal is completely hidden,

except in the lower Lumbar region. This interlaminar gap (Fig.2) is increased by

forward flexion of the spine: a combination of circumstances that makes Lumbar

puncture possible. [5]

Fig.1 A Lumbar vertebra in (a) lateral and (b) antero-superior views. [5]

Fig.2 The Lumbar interlaminar gap, this anatomical fact makes lumbar puncture possible. [5]

Chapter 1 Anatomy

5

2- Anatomy of Lumbar Puncture:

Lumbar puncture (or Spinal anesthesia) is usually performed with the patient

in the lateral or sitting position. Whichever position is chosen, the patient should be

asked to flex his/her spine as much as possible, there by widening the gaps

between the Lumbar spinous processes (Fig.3). The line that joins the top of the

iliac crests (the inter-cristal line) usually passes through the body of the 4th Lumbar

vertebra, and is therefore a useful landmark. The space above this line is usually

the L3/4 interspace, that below is usually the L4/5 interspace. The choice of

interspace is important, as the Spinal needle should not be introduced at a level that

may cause it to enter the Spinal cord. In the adult, the Spinal cord usually ends at

the level of the 1st Lumbar vertebra. However, in children, it may end as far

distally as the 2nd or even 3rd Lumbar vertebra. Spinal needles inserted for

diagnostic or anesthetic reasons should not therefore be introduced above the L3/4

inter-space except in exceptional circumstances. [5]

Fig.3 The anatomy of Lumbar puncture. [5]

Fig.4 Midsagittal view of the meninges, ventricles, subarachnoid spaces, and cisternae. [5]

Chapter 1 Anatomy

6

3- The Spinal Meninges:

The Spinal cord has three covering membranes or Meninges (Fig.4), the Dura

mater, Arachnoid mater and Pia mater. The compartments related to the Spinal

meninges are the Subarachnoid, Subdural and Epidural spaces. The Subarachnoid

space contains the CSF. It is traversed by incomplete Trabeculaea, the Posterior

Subarachnoid Septum and the Ligamentum Denticulatum. [5]

The Subdural space is a potential one only, the Arachnoid is in close contact

with the Dural sheath and is separated from it only by a thin film of serous fluid.

The Subdural space within the vertebral canal rarely enters the consciousness of

the clinician, unless it is the accidental site of catheter placement during attempted

Epidural analgesia or anesthesia. The Subdural injection of local anesthetic is

thought to be associated with patchy anesthesia, often unilateral and often

extensive. The Epidural (Extradural or Peridural) space in the Spinal canal is that

part not occupied by the Dura and its contents. [5]

Chapter 2 History

Chapter 2 History

7

Fig.6 The Patient lying with the CSA needle protruding from his back. [12]

History

1- CSA Needles:

While most were striving to improve the design of Spinal needles to decrease

the incidence of complications, some workers were looking at ways of improving

the technique of Spinal anesthesia to make it applicable to more surgical procedures.

Dean had described a technique of continuous Spinal anesthesia in 1907 in

which he left the Spinal needle in situ during surgery and injected more local

anesthetic solution as and when necessary "exploring needle", but his technique was

not widely accepted. [6] Lemmon published a paper in 1940 describing a 17G and

18G Nickel ⁄ Silver alloy malleable needle and introducer with a sharp, medium-

length, cutting bevel and a small opening in the long side of the bevel to enable free

flow of CSF (Fig.5). [7]

The needle was placed in the subarachnoid space, was bent at the skin surface,

and was attached to rubber tubing through which local anesthetic solution was

injected when required. The patient lay on a mattress and table that had a hole

placed so as to accommodate the protruding needle (Fig.6). On the introduction of

Stainless Steel, the needle was manufactured from Stainless Steel annealed to render

it malleable. [7]

In 1943, Hingson presented his modification of the Lemmon needle. [8] The

distal and proximal portions of the needle were rigid, with an annealed middle

Fig.5 Lemmon needle. [12]

Chapter 2 History

8

Fig.9 Tuohy Flowers needle. [12] Fig.10 Cappe and Deutsch needle. [12]

portion that was malleable. The tip of the needle was a short-beveled point with a

blunt cutting edge and an extra orifice near the tip. The hub had a reinforced steel

collar to connect to small-bore tubing. There was a safety bead to prevent needle

breakage (Fig.7).

The continuous Spinal needle had its problems and was technically difficult to

use and keep in position. In 1944, Tuohy used a 15G directional Spinal needle

through which he passed a Nylon Ureteric catheter into the subarachnoid space to

allow continuous Spinal anesthesia. [9] The needle had a fitted stylet with a matching

bevel (Fig.8). The medium length bevel had cutting edges. A year later, he

published an article describing an adaptation of his needle to incorporate a "Huber

tip", which allowed directional control of the catheter to point cephalad or caudal as

required, [10] Tuohy needle had a sharp inner edge to the bevel that caused shearing

of catheters, so it was modified.

Over the years, other modifications were made to the Tuohy needle. One

modification was the Tuohy Flowers modification, with a shorter and blunter bevel

and the stylet protruding beyond the bevel of the needle to ease insertion of the point

through tough ligaments (Fig.9).

Fig.7 Hingson Ferguson needle. [12] Fig.8 Tuohy needle. [12]

Chapter 2 History

9

Fig.11 CSA needle with Protective Shield over Lumbar spine. [12]

Fig.12 CSA needle metal protector. [12]

Following the introduction of the pencil-point needle for single-shot Spinal

anesthesia, it was inevitable that a similar needle would be introduced for

continuous Spinal anesthesia. Although Tuohy had already introduced the idea of

continuous Spinal anesthesia using catheters rather than needles, the large Tuohy

needles and catheters had a significant PDPH rate, so continuous Spinal needles

were still in common use. Cappe and Deutsch described a malleable cone-tipped

Spinal needle in 1953. It was 20G in diameter and had a Whitacre tip and an 18G

introducer (Fig.10). The middle portion had been annealed to render it malleable so

that the needle could be bent at the skin surface once the tip was in the subarachnoid

space. There was an adjustable needle stop to stabilize the needle. They reported a

PDPH rate of 6.6% in their needle group compared to 22% in the conventional

cutting-tip needle group. [11]

Several devices have been invented to help protect the CSA needle while it is

in the subarachnoid space like this shield (Fig.11) that is made of Plexiglass with a

central channel that accommodate the needle protecting it from dislodgment. Also,

there was another device which was called "Bishop's hat" (Fig.12) and was made of

metal, it was used to protect the needle and the rubber tubing in case the special

mattress for CSA wasn't available. [12]

Chapter 2 History

10

2- Large-Bore Catheters (Marco-Catheters):

As we mentioned, CSA was first described by Edward Tuohy in 1944 using a

Ureteric catheter via a 15G Huber point needle and initiating Spinal anesthesia with

incremental doses of local anesthetic. He reported no increase in the incidence of

PDPH compared with single injection techniques and no neurological

complications. [13,14]

In 1950, Dripps reviewed reports on single-shot Spinal anesthesia (SSSA) and

CSA with a malleable needle and catheter techniques. He found an 8% (43 of 506)

incidence of failed anesthesia with CSA compared with 1.9% (37 of 1921) with

SSA. Also, he found more technical difficulties with the catheter technique and a

significantly higher incidence of transient parasthesia (33%) than with single

injection techniques (13%). Over the next 25 years, CSA was not used much, as

reflected by the paucity of references in the literature, and it is hard not to conclude

that this was a direct result of Dripps’ article. [15]

Many studies were made later on CSA using large-bore catheters to detect the

differences between it and the single-shot Spinal anesthesia in the technique and the

complications. [16-20] The PDPH incidence was found to be around 1% in the elderly

population. [21-24] Other studies were also made to compare it with the Epidural

anesthesia reporting not only greater cardiovascular stability but a significantly

lower failure rate than Epidural anesthesia. [25-29]

3- Micro-Catheters:

The Spinal micro-catheter was described first by Hurley and Umbert. [30] Their

aim was to develop a sufficiently fine-bore catheter (32G) which could be threaded

through an appropriately fine Spinal needle (26G) into the CSF. Theoretically,

compared with large-bore catheters, this would enable CSA to be performed in

younger patients with a reduced risk of PDPH. Their initial study with the 32G

micro-catheter showed a 20% incidence of technical complications, similar

Chapter 2 History

11

experiences were also reported by others. [31] The 32G Spinal micro-catheter was

difficult to handle, CSF could not be aspirated and it had a very high internal

resistance, making injection of local anesthetic very slow.

A 28G catheter which could be passed through a 22G Spinal needle was then

developed (Kendall®). This catheter proved easier to use and did not have as many

technical complications. Later studies with 28G catheters have shown a technical

complication rate similar to that of large-bore catheters, including the incidence of

PDPH. [32] However, it was not long before cases of neurological complications, in

the form of Cauda-Equina syndrome, were described after CSA with micro-

catheters. [33] Further reports of problems with the micro-catheter technique [34] led

the FDA in 1992 to ban the use of Spinal catheters smaller than 24G in the USA,

while it was used in the rest of the world. [35] In all, approximately 12 cases of

Cauda-Equina syndrome after CSA with micro-catheters have been reported. [36]

Chapter 3 CSA Kits,Drugs and

Related Devices

Chapter 3 CSA Kits, Drugs and Related Devices

12

The Most Commonly Used CSA Kits

1- Catheter-Over-The Needle Type:

B Braun Spinocath®

Spinocath® features a catheter-over-needle design where the catheter is

positioned over the Spinal needle (Fig.13).

Fig.13 Spinocath catheter over needle Kit. [www.bbraun.com]

Fig.14 27G Quincke Spinal needle with braided wire attached to it and catheter over both of them. [www.bbraun.com]

It consists of a standard 27 or 29G Quincke Spinal needle, a 22 or 24G tapered

catheter tip that gently dilates the Dura and gives excellent tactile feedback and thus

the first identification of successful Dural puncture with a side hole that assures

aspiration through a second opening (Fig.14). The Perifix® catheter material is

characterized by its superior handling characteristics, easy injection, aspiration and

barbotage, good distribution of anesthetic and it is also suitable for syringe pumps


13

(such as Perfusor®). The Quincke needle has a fluid exit side hole that lies within

the catheter, and in addition the needle is connected to a smooth laser welded pull

wire that allows it's safe and easy removal after correct positioning of the catheter.

The kit also contains an 18G Epidural needle used to access the Epidural space

The technique of insertion consists of identifying the Epidural space by the

loss-of-resistance technique using the Epidural needle, then passing the Spinal

needle (with the catheter mounted on it) through the Epidural needle in a manner

that would be analogous to the needle through needle technique used for combined

Spinal Epidural anesthesia (Fig.15). Once the Dura is punctured, the needle is

advanced a little. CSF is detected within the catheter, as it emerges from the fluid

exit side hole in the Quincke needle, and the braided wire is then withdrawn which

also pulls back the Quincke needle, leaving the catheter within the intrathecal

compartment which simultaneously seals the hole in the Dura (Fig.16). The Epidural

needle is then withdrawn and the catheter is connected to a filter via a connector and

is then ready for use.

Perceived advantages of this technique include an unequivocal endpoint of

catheter placement in the Subarachnoid space because CSF can be aspirated through

the catheter, with assumed less incidence of PDPH. It is believed that CSF does not

leak because the hole made in the Dura by the Quincke needle is sealed by the wider

Fig.15 Passing the spinal needle through the dura. [www.bbraun.com]

Fig.16 Pulling on the wire to remove the needle from within the catheter. [www.bbraun.com]


14

bore catheter (Fig.17, 18). It is reported that there is a definite learning curve as

these catheters may be more difficult to insert than conventional catheters. [37]

2- Catheter-Through-The Needle Type:

(A) Standard Epidural catheter set

It usually consists of a 20G macro-catheter inserted through an 18G Tuohy

Epidural needle.

(B) Smiths Portex®

It consists of a 19G Tuohy needle with a 23G Crawford Spinal needle with

optimized 30 degree angle of bevel, the needle bevel heel and sides blunted to

minimize the risk of potential catheter shearing. Graduated markings permit

accurate catheter positioning. It contains 28G micro-catheter with PTFE coated

stylet that aids easy withdrawal from catheter (Fig.19).

Fig.17 Conventional catheter through needle design with CSF leaking from around the catheter. [www.bbraun.com]

Fig.18 Spinocath catheter over the needle design with the catheter sealing the dural puncture causing minimal CSF leak. [www.bbraun.com]


15

(C) Kendall CoSpan®

It consists of a 28G micro-catheter and 22G Quincke needle.

Those last two sets are considered micro-catheters, they may be more difficult

to insert and they kink easily if force is exerted during insertion. Once inserted, it is

virtually impossible to aspirate CSF from them. However, it is observed that if

sufficient time is allowed, one may occasionally see a drop of CSF emerge from the

end of the catheter. Although CSF emergence is an unequivocal end point of a

Spinal catheter placement, in routine clinical practice this would be an impractical

method of confirming catheter location. [38]

It is possible to overcome any resistance encountered during insertion of a 28G

catheter by removing the catheter from the needle, withdrawing the needle slightly

(ensuring CSF is still flowing from the needle) and then reinserting the catheter, an

alternative method is to inject a small amount of local anesthetic via the Spinal

needle and then insert the catheter. Although there are conflicting reports, no matter

which catheter is inserted, it is better to insert the catheter in the sitting position.

Insertion of a catheter more than 3 cm into the Subarachnoid space increases the

chance of a caudally directed catheter end position. [39]

Fig.19 Portex® Catheter through needle kit. [www.smiths-medical.com]


16

In a study made to compare between the Portex® system (micro-catheter) and

the Spinocath® system regarding PDPH in young adults no significant difference

could be demonstrated between the two systems with different techniques of Dural

perforation. However, analysis revealed a significantly shorter duration and reduced

severity of headache in the over-needle group as assessed by the standardized

headache assessment method. [40]

Whatever the chosen CSA kit is, it may be preferable to use a larger gauge

catheter, accepting a higher incidence of headache, but a lower incidence of

failure.[41]

Drug Agents That Can Be Used Intrathecally (IT)

Perhaps first among the important concepts that must be appreciated to conduct

CSA safely is attention to the doses of medication used. CSA requires small doses

of local anesthetics to achieve anesthesia and analgesia. Single-shot Spinal

anesthesia doses are approximately 1/10th the amount of local anesthetic used in the

Epidural space. CSA doses can be further reduced from doses needed with single-

shot Spinal anesthesia by 25 to 33%. [42] This translates into small doses of

Lidocaine (12.5–25 mg) or Bupivacaine (2.5–5.0 mg). In fact, when smaller

amounts of local anesthetics do not produce anesthesia at expected levels,

continuing to re-dose the same medication will often not produce more success but

may result in complications. Switching to a different local anesthetic and/or baricity

and/or re-positioning the patient may be the safer and a better plan.

Also important to remember is the relatively narrow "therapeutic to toxic

window" for local anesthetics in the Subarachnoid space. Animal studies have

shown that when CSA local anesthetic concentrations that do not cause Spinal cord

injury are doubled, nerve damage is seen. [43]


17

1- Lidocaine

Lidocaine has been shown to be particularly problematic in animal studies at

both high and low concentrations. Clinical evidence bears out that an excessive

amount of 5% hyperbaric Lidocaine has been associated with Cauda-Equina

syndrome in 1991. It is difficult to recommend Lidocaine of any concentration or

baricity for initial use with CSA. More than a decade of laboratory studies and

clinical results support the premise that intrathecal anesthesia can be performed

without Lidocaine. [44]

First, both Cauda-Equina syndrome and transient neurological symptoms are

more frequent events after intrathecal Lidocaine than after Bupivacaine. Decreasing

both dose and concentration have not solved these problems. Considering Lidocaine

to be a dangerous medication appears to be counter-intuitive to many

anesthesiologists. [45] At least in the opinions of some authors, Lidocaine should be

avoided for Spinal anesthesia. [46]

A possible role for Lidocaine may be with the rescue of (initially) failed CSA.

Kung et al have shown that in 11 (out of 236) cases where CSA initially failed to

produce T10 sensory anesthesia with 20 mg of (0.2%) Bupivacaine, surgical

anesthesia was produced by switching to 1% Lidocaine solution. [47] It would be

more prudent and safer to stop Bupivacaine at a lower dose (10 mg) when

considering switching to Lidocaine. These observations are similar to those made by

others who have shown a relative resistance to a local anesthetic that could be

overcome with another local anesthetic. [48] However, continuing to dose with any

one or a combination of local anesthetics is not advisable if no block or a block

limited to sacral dermatomes develops despite aspiration of CSF.

2- Bupivacaine

All types of concentrations and baricity of Bupivacaine solutions have been

used to conduct CSA safely. Bupivacaine in low concentrations (0.1–0.2%) can


18

also be used alone or in combination with Opioids to provide postoperative

analgesia. For initial injection of CSA, 2.5-5.0 mg of either plain or hyperbaric

Bupivacaine should produce a T10 sensory level of anesthesia. Additional

incremental doses, using 2.5 mg, will expand and solidify the block. However,

injection must stop at an absolute maximum of 12.5 mg of Bupivacaine even if this

means that an alternative anesthetic technique is needed as there is no local

anesthetic that is entirely non-toxic to nerves. While Bupivacaine is safer than

Lidocaine, it can produce neurological injuries after intrathecal use. [49]

3- Ropivacaine

Intrathecal Ropivacaine has not been shown to be toxic in animal models. [50]

Human data from single-shot Spinal anesthesia appear to support a clinical role for

Ropivacaine. However, its major advantage of its use with Epidural anesthesia,

brachial plexus anesthesia and other forms of regional anesthesia where large

amounts of local anesthetic solutions are injected, is lost with intrathecal use. Also,

Ropivacaine lacks the large body of clinical evidence to support its safe use that is

available with Bupivacaine. The intrathecal potency ratio for Ropivacaine compared

with Bupivacaine has been estimated as 2:1. [51]

4- Levobupivacaine

A Study was made to assess the minimum effective local anesthetic dose

(MLAD) of Levobupivacaine and Ropivacaine in the context of continuous Spinal

anesthesia with Spinal catheters that allows incremental dosing of local anesthetic.

The results were that the MLAD of Levobupivacaine was 11.7 mg and that of

Ropivacaine 12.8 mg. However, the small numerical difference (1.1 mg) in the

MLADs does not allow us to make the interpretation that Levobupivacaine would

be more potent than Ropivacaine, as the 95% confidence intervals overlap. [52]


19

5- Procaine

Procaine would appear to be a useful agent for CSA. Both its potency and

baricity can be altered to fit the circumstances. Its short duration of action is also

suited to a catheter technique. [53]

6- Tetracaine

Tetracaine can be used with CSA but, as a long-acting agent, it may reduce the

flexibility of the technique. [53]

7- Opioids

(A) Fentanyl: Intrathecal Fentanyl, alone or in combination with local

anesthetics, can produce excellent postoperative analgesia. There is evidence that

Fentanyl may also extend and solidify the anesthetic when used in single-shot

Spinal anesthesia allowing using smaller dosess of intrathecal Bupivacaine. It is

likely that these smaller doses of Fentanyl (25 µg) can be used the same way with

CSA. It is of interest that while intrathecal doses with local anesthetics is on the

order of 1/10th the doses needed in the Epidural space, the requirements for

intrathecal Fentanyl do not follow this pattern. The hourly Fentanyl dose should be

limited to 25–50 µg given as a bolus or infusion, as larger amounts have been

associated with increasing respiratory depression. [54]

(B) Sufentanil: Given in 5-10mg boluses and limited to 40 mg, produced safe

and effective post operative analgesia. [54]

Used alone, these lipid-soluble Opioids may be sufficient for certain

procedures such as lithotripsy.

(C) Morphine: Can also produce safe and effective postoperative analgesia.

Initially, higher doses (1–20 mg) were shown to produce profound analgesia. The

trend over the past several years has been to employ much lower intrathecal


20

Morphine dosing (in the range of 0.1–0.4 mg/day) to avoid side effects. Avoiding

side effects at the cost of less profound analgesia does not seem a good trade-off,

however. We can produce low pain scores (0–4/10) while limiting complications in

carefully monitored environments (intensive care environment) with Morphine

infusions of 1-2 mg per day. In high-risk patients, or in less-well-monitored settings,

lower-dose Morphine would be appropriate. However, in a study made by J. G.

Forster et al on a total of 47 patients (range 51–95 years, ASA II–IV), they found

that the combination of low-dose Ropivacaine and Morphine for continous Spinal

postoperative analgesia did not offer any benefit compared with the higher

Ropivacaine dose alone. [55]

(D) Meperidine: (0.75–1.0 mg/kg) can be used as a sole Spinal agent because,

in addition to being a mu Opioids agonist, it produces reversible motor and sensory

anesthesia. [56]

Finally, whatever the Opioid used, careful patient monitoring is indicated.

8- Other Agents

(A) Magnesium Sulfate: A study was made by R. Arcioni et al to detect the

effect of Magnesium sulfate (MgSO4) on altering pain processing and reduction of

the induction and maintenance of central sensitization by blocking the N-methyl-D-

aspartate (NMDA) receptor in the Spinal cord. They investigated whether

supplementation of Spinal anesthesia with combined intrathecally and Epidurally

infused MgSO4 reduced patients’ post-operative analgesia requirements or not. They

found that direct intrathecal administration of MgSO4 prolongs the action of

Subarachnoid anesthesia in animal and human subjects. This administration route

has been shown to be clinically safe in humans, [57] and its safety profile has been

evaluated in several experimental settings, including histopathologic analysis. [58]


21

On the other hand, another trial made by R. Arcioni et al, they enrolled 120

consecutive patients undergoing orthopedic surgery under Spinal anesthesia

concluded that for major orthopedic surgery, supplementation of Spinal anesthesia

with combined intrathecally injected and Epidurally infused MgSO4 considerably

reduces patients’ post-operative PCA requirements, compared with Spinal

anesthesia alone, simply, reliably and without inducing short term or long term

adverse reactions. They stated that these encouraging findings in a small study

sample suggest that, once MgSO4 is approved for intrathecal and Epidural use, a

low-cost, simple change in clinical anesthesiology practice will do much to decrease

patients’ post-operative analgesic needs. [59]

While comparing the sensory, motor and analgesic block characteristics of

Magnesium (50mg) with Fentanyl (25mg) and Saline when added to 0.5%

Bupivacaine (10mg), it was found that the addition of Magnesium Sulfate (50mg)

to 10 mg of Spinal Bupivacaine (0.5%) did not shorten the onset time of sensory and

motor blockade or prolong the duration of Spinal anesthesia, as seen with

Fentanyl.[60]

(B) Baclofen: It is a synthetic pre- and postsynaptic γ aminobutyric acid

receptor type B (GABAB) agonist. It decrease excitatory synaptic release of

neurotransmitters such as Aspartate and Glutamate and also decrease Substance P in

nociceptive afferent nerve endings thought to cause painful flexor spasms.

Determining the etiology of the spasticity is critical for therapeutic benefit. [61]

Generally speaking, patients with Spastic Diplegia secondary to Spinal cord injury,

Familial Spastic Paraparesis, Multiple Sclerosis, spasticity following Ischemic

Stroke and Spondylitic Myelopathy, also patients with spasticity of cerebral origin

may benefit from intrathecal (IT) Baclofen. [62] Notably, IT Baclofen also may be

beneficial in the treatment of patients with severe Spastic Hemiplegia. [63]


22

(C) Neostigmine, Diazepam, Aspirin (and other non-steroidal anti-

inflammatory drugs), Alpha Agonists (Clonidine and Dexmedetomidine), Ketamine,

etc. (medication to change the balance of Spinal Cytokines, Leukotrienes and

Substance P) may have a role in producing intrathecal analgesia in both chronic and

acute pain, but their usefulness for intrathecal use in the perioperative period

remains to be defined. [63]

The continuing access provided by Spinal catheters will be important as the

safety and efficacy of these (and other) agents are demonstrated.

Implantable Intrathecal Drug Delivery Systems (Pumps)

Intrathecal drug delivery systems are implanted for chronic pain when

conservative therapies have failed, surgery is ruled out, no active or untreated

addiction exists, psychological testing indicates appropriateness for implantable

therapy, medical contraindications have been eliminated (coagulopathies,

infections), and finally, a successful intrathecal drug trial has been completed. [64]

Patients needing intrathecal drug delivery can be divided into 2 broad

categories:

1- The 1st category: Includes patients suffering from terminal illnesses such as

cancer. These individuals generally respond well to intrathecal Opioids if they have

been successfully managed on oral Opioids first. Invasive therapy should be

considered if they have developed increasing pain and intractable side effects

despite rotating oral Opioids. However, if patients are terminal and their life

expectancy is less than six months, one has to weigh the benefits vs. the risks of

such a venture. This type of therapy is generally recommended for individuals with

a life expectancy of greater than six months. [65] It is important to rule out the

presence of occult pathology in the Spinal canal and any obstructive metastasis in

the Spinal column that could present a challenge during insertion of the catheter.


23

Fig.20 Intrathecal drug delivery system: pump (above) and catheter (below). [67] Fig.21 Lateral view showing the

advantage of using an oblique approach to the spinal canal. The catheter can easily be advanced if a shallow angle is used. [67]

2- The 2nd category: Patients with chronic non-malignant pain, for example,

failed low back surgery syndrome. The use of intrathecal drug delivery systems in

chronic non-malignant pain is more controversial. [66] Clearly, treatment for chronic

pain should consider conservative approaches before more invasive treatments are

considered. [67]

Intrathecal pumps deliver small doses of medication directly to the Spinal fluid.

It consists of a small battery-powered, programmable pump that is implanted under

the subcutaneous tissue of the abdomen and connected to a small catheter tunneled

to the site of Spinal entry (Fig.20). Sophisticated drug dose regimens can be

instituted. Implanted pumps need to be refilled every 1 to 3 months. There is no

evidence showing whether it is more clinically effective to use bolus or continuous

dosing. [67]


24

Pump insertion:

The placement of an implantable intrathecal pump consists of the catheter

placement followed by implantation of the pump. A shallow angled paramedian

approach with the Touhy needle allows easy rostral advancement of the catheter into

the intrathecal space (Fig.21). Positioning of catheter is checked with Fluoroscopy.

After removing the needle, the catheter is anchored to the Supraspinous Fascia using

a silastic anchor provided by the manufacturer. [68]

After the pump is prepared, an incision for the pump pocket is made in the

right or left lower quadrant of the abdomen at or about the Umbilical level. The

pump should be placed below the belt line, but not too close to the anterior rib or

Iliac Crest as it may lead to prolonged discomfort. Because of refilling

requirements, it is important not to place the pump too deep. In an obese patient the

pump should be placed at the mid-fat plane of the lower quadrant of the abdomen. If

the patient is thin, then the pump may be placed at the Rectus Fascia. The incision

for the pump pocket should be made just large enough to accommodate the pump.

After creating the pump pocket, tunneling from the pump pocket to the back wound

should be done with the tunneling device. [69] It is vital that the tip of the tunneling

device remains subcutaneous to prevent entering the peritoneal cavity or pleural

cavity. The pump should be secured to the pocket by suturing to the abdominal

fascia under the pump pocket (Fig.22).

Fig.22 Intrathecal pump and catheter assembly. [67]


25

Medications used in implantable intrathecal drug delivery systems:

1-First line agents: Includes Morphine and Hydromorphine, and has clear

support from data and extensive clinical experience.

2-Second line agents: May actually be chosen as first line in cases where an

individual has prominently neuropathic symptoms. This consists of either

Hydromorphine or Morphine with the addition of Bupivacaine or Clonidine. There

is little data to confirm the safety of these mixed agents. [70]

3-Third line agents: Show clinical promise but both evidence and clinical

experience is extremely limited. They are chosen only after failure of first and

second line drug combination treatments, either due to intolerable side effects or

inadequate analgesia. These drug combinations include adding both Bupivacaine

and Clonidine to either Morphine or Hydromorphine. [71]

4-Fourth line agents: They are not supported by much clinical research

evidence and experience. They include lipophilic Opioid agents such as Fentanyl

and Gamma Aminobutyric Acid (GABA) agonists such as Baclofen and

Midolazam. The reasoning behind using lipophilic Opioids is that there would be

less drug diffusion to the rostral brain centers. [72]

Finally, which equipment to use is largely determined by personal experience,

as few people will have extensive experience of more than one manufacturer’s

design. Also the technique of insertion will depend on the type of CSA set used. Our

advice would be to only use CSA where the staff has been given both verbal and

written instructions. In addition, equipment should be clearly marked as an

intrathecal infusion. Where infusions are used, we would recommend that closed

systems are used with all the connections taped, to reduce the risk of both the wrong

drug being injected and infection being introduced. We would also recommend that

at present, CSA should be performed by experienced anesthetists.

Chapter 4 Indications & Advantages


26

Indications & Advantages of CSA

Conventional Spinal anesthesia is simple, safe and well established. Why then

should anyone choose to complicate the issue with a catheter? This is currently the

view of most anesthetists and it is a view with much to comment it. However,

single-shot Spinal anesthesia (SSSA) does have limitations as the block may wear

off before surgery is complete. Although there is little published work on the safety

of administering sedation or general anesthesia immediately after Spinal anesthesia,

anecdotal evidence points to significant problems, especially with hypotension. [73]

Lastly, there is the problem that the Spinal anesthesia provides exceptional analgesia

for the surgery and recovery period, but does not provide analgesia postoperatively.

There are also many patients for whom the risk of complications of SSSA, such as

muscle paralysis, hypotension and the risk of a high block may lead to general

anesthesia being considered.

A major advantage of CSA over continuous Epidural anesthesia is the

improved efficiency in operative situations. In a retrospective review, Sutter et al

showed a significantly higher failure rate with continuous Epidural anesthesia (9%)

compared with CSA (1.7%), with half of the Epidural failures recognized only after

the start of surgery. [73]

It has been thought that continuous Epidural anesthesia will provide greater

intra and postoperative flexibility and controllability than CSA, as it can be placed

in proximity to the Spinal cord segments involved with surgery. While CSA

provides continuous access to the Subarachnoid space where factors such as

baricity, concentration and volume of the injectate can be used to influence the

spread, duration and extent of anesthesia/analgesia. Also, with the use of smaller

volumes and injection into the CSF, the patient will have markedly decreased blood


27

levels of medication. But this is not to imply that CSA can or might replace

continuous Epidural anesthesia in every situation. [74]

However, even in cases such as thoracic surgery, where segmental thoracic

anesthesia/analgesia may be perceived as standard of care, CSA can offer an

effective and safe alternative. [74] Finally, due to these factors, and combined with

the fact that correct catheter position is (almost) always verifiable with catheters of

all sizes by the flow of CSF, CSA allows the use of regional anesthesia when

Epidural anesthesia would not be recommended (as in Aortic Stenosis &

Hypertrophic Cardiomyopathy) [75] or might be difficult (as in severe obesity &

extremity of age). [76]

Continuous Spinal anesthesia (CSA) may therefore have a role in many

patients and in many situations. Evidence based data suggests that there are several

groups of patients for whom CSA can be useful:

I- Obstetric and Gynecological Procedures:

1- Routine normal labors.

2- High risk normal labors.

3- High risk Caesarian sections.

4- CSA was found to be also specially beneficial in pregnancy with

coexisting Aortic stenosis, Eisenmenger’s Syndrome, Cardiomyopathy and

Scoliosis.

II- Surgeries in the Lower Part of the Body with or without Coexisting Disease:

1-Ankylosing Spondilitis.

2-Orthopedic elderly patients.

3-Urological elderly patients undergoing endoscopic procedures.

4-Patients undergoing vascular interventions in the lower half of the body.

5- Patients undergoing interventions for repair of Aortic aneurysms.

6- General surgical patients undergoing major abdominal surgeries.


28

7- Morbidly obese patients.

III- Pediatric Open Heart Surgery.

I- Obstetric and Gynecological Procedures

1- Routine Normal Labors:

It was first described by Carpenter et al [77] in 1951 using an infusion of

procaine via a reusable vinyl catheter inserted through an 18G Quincke Spinal

needle. The resulting analgesia was satisfactory, but the technique was limited by

the inevitable headache associated with the large gauge needle and catheter. During

the late 1980s, the development of 28G or smaller catheters that could pass through

a 22G needle stimulated a resurgence of interest in continuous intrathecal labor

analgesia. In 1990, Benedetti and Tiengo described repeated intrathecal injections of

0.25% Bupivacaine via a 32G Spinal catheter producing satisfactory labor analgesia

in 12 parturients. [78]

Other investigators described successful continuous intrathecal labor analgesia

using combinations of both dilute local anesthetics and Opioids given via a small-

gauge catheter, as Valerie A.Arkoosh et al. who published a study discussing safety

of continuous Intrathecal Labor analgesia using a 28G catheter versus continuous

Epidural labor analgesia, they concluded that providing intrathecal labor analgesia

with Sufentanil and Bupivacaine via a 28G catheter has an incidence of neurologic

complication less than 1%, and when compared to Epidural analgesia it produces

better initial pain relief and higher maternal satisfaction, but is associated with more

technical difficulties and catheter failures, with no significant differences regarding

post-dural puncture headache or hemodynamic stability. [79]

Cardiac disease in pregnancy is now the leading medical cause of maternal

mortality in the UK. Whilst anesthesia has not been the precipitant of this morbidity,

its safety cannot be taken for granted. [80]


29

2- High Risk Normal Labors:

Epidural analgesia usually produces reliable analgesia, however patchy or

incomplete pain relief remains a distinct possibility, especially in the event of

emergency Cesarean Section, a dysfunctional Epidural catheter can cause time loss

and intraoperative pain and may necessitate unplanned conversion to general

anesthesia. In addition, if urgent Cesarean Section is required, Epidural anesthesia

for operative delivery has a slow onset. A Spinal catheter allows rapid extension of

the block whilst at the same time anesthesia can be titrated, limiting the

hemodynamic effects of Spinal anesthesia. [81]

So it has been found that continuous Spinal analgesia during normal labor can

offer the advantage of greater cardiovascular and hemodynamic stability combined

with analgesia, without the undesirable local anesthetic effects such as motor

blockade for all the duration of labor, this is of special interest in parturients in

whom hemodynamic stability is essential as with coexisting heart disease. [82] . The suggested regimen consists of an initial dose of Fentanyl 25 µg added to

1.5 ml of saline. If a parturient complained of pain 15 min after the initial dose of

Fentanyl, or thereafter, an additional 10 µg dose of Fentanyl could be injected up to

every 15 min throughout the first stage of labor. In the second stage, 0.5% heavy

bupivacaine 2.5 mg with saline 0.5 ml can be used to provide analgesia. Spinal

Fentanyl provides effective analgesia during the first stage of labor, but during the

second stage it is necessary to supplement with low-dose local anesthetic. The dose

of Bupivacaine used in conjunction with Fentanyl is minimal and significantly less

than that required when local anesthetic is used alone. [83,84]

Also intrathecal Fentanyl can be given as a 25mg plus Epinephrine 50mg

(diluted with 5% Dextrose, total 1.5 ml) bolus through the intrathecal catheter,

followed by an hourly infusion of Fentanyl 25mg plus Epinephrine 50mg (diluted


30

with 5% Dextrose at the infusion rate of 5.0 ml/h). Epinephrine can be added to

augment the analgesic effect of intrathecal Fentanyl, which is hypothesized to

stimulate Alpha-2 receptors, this combination can provide adequate analgesia in

early labor with rapid onset of analgesia and without evidence of sympathetic

blockade, resulting in good hemodynamic stability. [85]

3- High Risk Caesarian Sections:

Beside the disadvantages mentioned before for Epidural analgesia in normal

labor, other options exist in case of Caesarian Section:

- General anesthesia: It excludes women from the birth experience and cannot

match regional anesthesia for the quality of immediate postoperative analgesia.

- Single-Shot Spinal: It may result in unpredictable hemodynamic changes.

- Combined Spinal-Epidural (CSE): It may be is suitable alternative, and was

the most commonly used technique and its successful use has been described in

numerous case reports. [86] However, as CSE anesthesia requires an initial

intrathecal drug bolus followed by Epidural supplements, early hemodynamic

instability and subsequent unreliability are theoretical concerns.

So CSA may offer the potential to avoid these problems and provide safe and

adequate anesthesia in these High risk patients. CSA can be performed in these

cases by injecting 0.5% hyperbaric Bupivacaine in 0.25 ml increments with 25µ

Fentanyl. Some authors also recommend using the Spinocath® system to help

decrease the incidence of PDPH. [87]

4- CSA was found to be also specially beneficial in pregnancy with the

following coexisting diseases:

(1) Aortic Stenosis:

The pathophysiology of Aortic stenosis is affected by the normal

cardiovascular changes of pregnancy, such as a decrease in systemic vascular


31

resistance and an increase in circulating volume, so the anesthetic management of

these pregnant women focuses on hemodynamic stability including maintenance of

adequate pre-load, preservation of sinus rhythm, protection against tachycardia and

extreme bradycardia, also avoidance of systemic hypotension, myocardial ischemia

and myocardial depression are critical for a successful outcome. [88]

During anesthesia and surgery, patients with Aortic stenosis are at higher risk

for morbidity and mortality. A high maternal mortality has been reported and the

use of Neuraxial analgesia for labor pain in these patients is controversial because of

the potential detrimental effects of reductions in venous return and systemic

vascular resistance, in the time that strategies to prevent or treat hemodynamic

changes, such as the administration of Ephedrine or IV fluids can cause serious

problems. [89] Some authors question the use of Epidural or Spinal analgesia and

anesthesia in these patients, [90] while several others support the use of low dose

continuous Epidural analgesia or titrated Epidural anesthesia for Cesarean Section in

this patient group. [91]

There is evidence, however, that regional techniques can be used safely in

these patients. [92] Lao et al., for example, reported on 20 pregnancies in parturients

with Aortic stenosis who either delivered vaginally or by Cesarean Section, in all

women Epidural anesthesia was used successfully. [93]

Successful use of CSA for labor analgesia in patients with moderate to severe

Aortic stenosis was reported by many authors. [94-96] Good planning, invasive

monitoring, senior staff involvement and the availability of an experienced obstetric

anesthetist routinely involved in the management of high-risk pregnancies are

important components of a successful outcome.


32

(2) Eisenmenger’s Syndrome:

The goal of anesthetic management of a patient with Eisenmenger’s syndrome

is the maintenance of SVR to prevent increases in right-to-left shunt, the maternal

mortality of Eisenmenger’s patients in vaginal deliveries (34%) is much lower than

that in Cesarean Sections (75%). [97]

Both general and regional anesthetic techniques have been reported. In the

respiratory management of general anesthesia, intermittent positive pressure

ventilation causes decreases in venous return and cardiac output and increases in

pulmonary arterial pressure, which together produce an increase in right-to-left

shunt. [98] While single-shot Spinal may induce excessive sympathetic block and

decreased SVR [99] and may be associated with the additional risk of Subdural

hematoma, because heparin is frequently given to parturients with Eisenmenger’s

syndrome. [100]

The application of Epidural anesthesia has also been reported in parturients

with Eisenmenger’s syndrome undergoing elective Cesarean Section. [101]

Cardiovascular changes are relatively gradual but the onset of effect is slower than

that of single-shot Spinal anesthesia and also the large doses of local anesthetics

used can cause myocardial depression and hypotension, and the risk of bleeding into

the Epidural space is higher than in Spinal anesthesia. Also incomplete Epidural

anesthesia may induce undesirable sympathetic stimulation or the need for intra-

operative conversion to general anesthesia. [102]

On the other hand CSA provides a titratable and reliable Neuraxial block using

minimal doses of local anesthetics, and has been used successfully in the anesthesia

of parturients with Eisenmenger’s syndrome undergoing Cesarean Section, but

careful monitoring of vital signs and prompt treatment of hypotension by

Phenylephrine or Ephedrine to maintain SVR are essential. [103]


33

(3) Cardiomyopathy:

Anesthetic management of patients with severe Cardiomyopathies include

avoidance of myocardial depressants and cautious fluid management with judicious

use of diuretics and vasodilators. In addition, basics of anesthetic management

appropriate for other patients with limited cardiac function also apply, in other

words, sinus rhythm must be maintained and extremes of blood pressure and heart

rate should be avoided. [104]

Severe myocardial depression and cardiac arrest have been reported as a result

of administration of general anesthesia to these patients. Continuous Spinal

anesthesia appears to offer more hemodynamic stability than single-shot Spinal for

Cesarean Section, as has also been shown with knee and hip surgery. Hemodynamic

stability has been found to be similar to that with Epidural anesthesia. Furthermore,

CSA may be more rapidly and effectively titratable. [105] However, care should be

taken as anticoagulant therapy is often indicated in these patients due to increased

risk of thromboembolic events. [104] So CSA was found to be the most adequate

method of anesthesia for these patients during Normal Labor or caesarian

Section.[85,106]

(4) Scoliosis:

CSA may also be beneficial in Caesarian Section or normal labor analgesia for

these parturients, as titration of the local anesthetic can help avoid unintentional

wide spread of anesthetic agents caused by distortion of the Spinal canal due to

spine deformity or the operation for its correction or any implanted instrument. [107]


34

II- Surgeries in the Lower Part of the Body with or without Coexisting Disease

In general practice of CSA, Plain Bupivacaine 0.5% can be injected through

the intrathecal catheter in a 0.5 ml bolus, with additional boluses of 0.5 ml at 5 min

intervals until the required block is achieved or a maximal dose of 3 ml has been

administered. Because plain Bupivacaine is isobaric, the solution initially remains at

the point at which it was injected and then diffuses in both caudal and cephald

directions.

The clinical picture is of a block which starts in the lumbar area and then

spreads toward mid-thoracic and sacral levels over a period of around 10 min.

Fentanyl can also be added in a maximum dose of 25µ per hour as a bolus or as a

continuous intrathecal infusion.

1-Ankylosing Spondilitis:

Lower body surgeries in such patients can be performed under regional or

general anesthesia. Regional anesthesia techniques described for such patients

include Epidural, Spinal, combined Spinal Epidural. These patients present with

some unique problems for the anesthesiologist, like limited respiratory excursion

corresponding to restrictive lung disease, difficult airway due to fused cervical

spine, difficulty in performing regional block due to fused Spinal spaces, risk of

sublaxation of Atlanto-Axial joint and increased risk of Cervical Spine fracture,

making both general and regional anesthesia problematic. [108]

The CSA is beneficial here because of well defined endpoint of procedure and

option of reliable, predictable and fast prolongation of duration of block, but it must

be performed with provision of difficult airway, so difficult intubation cart should


35

be prepared including Fibreoptic Bronchoscope and alternate airways like Laryngeal

Mask and airway management devices in case of need of assisted ventilation. [109]

2-Orthopedic Elderly Patients:

Both general and regional anesthesia is associated with side effects in geriatric

patients. [110] Although regional anesthesia might have benefits over general

anesthesia, hemodynamic stability may be impaired and can lead to myocardial

ischemia. [111] Hypotension is more common, and also more hazardous, in elderly

patients, as they may have decreased physiological reserve and compromised blood

supply to various vital organs. [112] Many different techniques, such as IV crystalloid

and vasopressor administration, have been used to attenuate this complication. [113]

However, rapid infusion of large amounts of IV fluids may be detrimental to

patients with cardiac dysfunction. [114] Moreover, Ephedrine and vasopressor can

lead to serious cardiac side effects (excessive hypertension or tachycardia). [115]

CSA here can accomplish the advantages of regional anesthesia and in the

same time better hemodynamic stability, this was supported by a study made on 74

patients aged >75 years who underwent surgery for open surgical repair of hip

fracture, where the hemodynamic effect of continuous Spinal anesthesia (CSA) and

small dose single-shot Spinal anesthesia (SSA) were compared. They found that the

incidences of hypotension were significantly lower in the CSA group, as in the SSA

group, 51% of the patients experienced at least one episode of severe hypotension

versus 8% of patients in the CSA group, also the amount of local anesthetic solution

was smaller in the CSA group ([2.5–10] versus 7.5 mg) and resulted in the lower

level of sensory block. [116]

Also another study including 68 patients aged between 50 & 85 years

undergoing elective hip surgery showed that CSA provided better hemodynamic

stability during induction of anesthesia compared with SSA in addition to better


36

postoperative analgesia with less nausea and vomiting than patient-controlled

intravenous analgesia with Morphine while the influence of possible drawbacks of

applying continuous Spinal analgesia, such as prolonged immobility and the need

for close monitoring is limited since the majority of patients taking advantage of this

technique are old and severely disabled, moreover, rehabilitation does not start

within 24 h after surgery. [117]

3-Urological Elderly Patients Undergoing Endoscopic Procedures:

These surgeries usually require anesthesia in the sacral segments to cover the

insertion of the Cystoscope, as well as the lower thoracic segments to prevent the

discomfort caused by bladder distension. The catheter is inserted in the sitting

position and its tip is directed caudal and 0.5 ml of 0.5% heavy Bupivacaine is

administered and the patient is left sitting for 5 minutes. The patient is then asked to

return to the supine position after which further boluses of 0.5 ml of 0.5% Plain

Bupivacaine is administered as mentioned before till the required level of sensory

block is achieved. [82] Injecting hyperbaric Bupivacaine first in the sitting position is

to achieve good anesthesia and motor block of the lower abdomen and lower limbs

and then utilizing isobaric Bupivacaine to fine tune the spread of the sensory block

without resorting to various manipulations of posture which may be required with

hyperbaric Bupivacaine if used alone. Isobaric Bupivacaine used during continuous

Spinal anesthesia in the supine position produces a suitable and a more controllable

anesthesia. [125]

4- Patients Undergoing Vascular Interventions in the Lower Half of the Body:

These patients are often extremely unwell as the disease process that affects

vessels in the lower half of the body that require surgical intervention (as

Atherosclerosis or Vasculitis) commonly affects vessels in other parts of the body

too (as Coronaries and/or Carotids), and also such patients require good post-


37

operative analgesia. CSA can be used in these patients in the manner described

before with plain Bupivacaine to minimize cardiovascular instability. For the

postoperative period, the catheter can be left connected to a PCA (patient controlled

analgesia) device programmed to deliver a bolus of 0.5 ml of 0.25% plain

Bupivacaine with a lockout of 5 min. [118]

In these patients CSA provides a significantly lesser incidence of decrease in

blood pressure and lower incidence of vasopressor use when compared to controls

receiving continuous Epidural anesthesia. [119] It also avoids many of the

disadvantages of General Anesthesia as the hemodynamic responses of direct

laryngoscopy and intubation, in addition, the use of volatile anesthetics may lead to

myocardial depression and peripheral vasodilatation. Also in a patient with

coexisting chronic obstructive lung disease (COPD), complications associated with

positive pressure ventilation and possible infectious risks associated with intubation

are avoided. [120]

5- Patients Undergoing Interventions for Repair of Aortic Aneurysms:

Endovascular Stent Graft Repair of Aortic Aneurysms is increasingly common

in patients who are at high medical risk and have vascular anatomy that is amenable

to this approach. [121] Regional anesthesia is frequently administered because of the

need to perform open surgery on the Femoral artery or distal Aorta, combined with

the desire to avoid general anesthesia and endotracheal intubation in patients with

severe cardiac and pulmonary disease. Also during open thoracic aortic aneurysm

repair, lumbar drainage has been advocated to prevent, or reduce, Spinal cord

ischemia by reducing cerebrospinal fluid (CSF) pressure and improving Spinal cord

perfusion. [122]

The first case of combined Lumbar CSF drainage and Spinal Anesthesia

administration through the same catheter in the management of Endovascular Stent


38

Graft Repair of a Thoracic Aortic Aneurysm was presented by Shin Su Kim et al in

their case report of a 78 year old man presenting with a Thoracic Aortic Aneurysm

that originated immediately distal to the orifice of the left Subclavian artery, despite

the drainage of CSF, the duration of anesthesia was approximately the same as

would be expected from a single shot administration without CSF drainage. This

finding might show that the local anesthetic remaining in the CSF after initial

binding to the Spinal cord and nerve roots is not a significant contributor to the

duration, or density, of the Spinal anesthesia. [123]

6- General Surgical Patients Undergoing Major Abdominal Surgery:

There are only few reports in the literature regarding the use of CSA in

abdominal surgeries requiring higher level of sensorial block, but one of them

described its successful use in 52 patients (ASA III-IV) undergoing major

abdominal surgeries resulting in a 91% patient satisfaction without any significant

complications. [124]

It should also be noted that patients with multiple co-morbidities are usually

aware that they are at higher risk, and are usually prepared to endure a bit of

discomfort if it means they are given a chance to overcome the potential life

threatening medical problem that has brought them to the attention of the

anesthetist.[125]

Another case series demonstrated the effective use of CSA using a micro-

catheter as a primary method of anesthesia in high-risk patients undergoing

colorectal cancer and other major abdominal surgery (A total of 89 patients, ASA

IV) [126] without any serious hemodynamic derangements except occasional mild

hypotension which responded well to I.V fluid load and with an incidence of PDPH

similar [127] or lower [128] compared to other published studies.


39

Postoperative pulmonary complications have been reported to occur in 4-22%

of patients undergoing abdominal surgery under general anesthesia. [129] Patients

with severe obstructive airway disease have a 37% incidence of postoperative chest

complications and it is suggested that avoiding general anesthesia with endotracheal

intubation may decrease the risk of postoperative bronchospasm and decrease the

risk of stay in intensive care. [130] CSA is also known to minimize the risk of

cardiovascular and respiratory disturbances [131] and since respiratory depression is a

well-recognized side effect of Spinal Opioids, using relatively small doses of

Fentanyl (25µ/hour max) and also avoiding the concomitant administration of

sedatives will prevent this complication. [132]

7- Morbidly Obese Patients:

Many benefits have can be identified for Epidural anesthesia and analgesia

intraoperative and during the postoperative period in these patients, including

reduced postoperative pulmonary and thromboembolic complications, better

preservation of cardiac function, reduced total Opioid consumption, and early

ambulation and discharge from hospital. All the above benefits attributed to

Epidural anesthesia also apply to CSA. However, there are distinct advantages of

the CSA/A over the continuous Epidural technique. These are: technically easier

catheter insertion in obese patients, maximal anesthetic/analgesic effect with a

minimum amount of drug, faster speed of onset, and predictable and controllable

level of anesthesia and analgesia. [133]


40

III- Pediatric Open Heart Surgery

Infants and children undergoing cardiac surgery mount a substantial stress

response, [134] and in neonates, this has been shown to be associated with adverse

outcome. [135] High-dose intravenous Opioid techniques can reduce or even

eliminate these responses to non-bypass surgery, but they remain substantial during

and after cardiopulmonary bypass (CPB), even when very large doses of Opioids are

used. [136] Nevertheless, partial suppression with Opioids can improve markers of

myocardial damage in adults and reduce morbidity and mortality in neonates. CPB

is also associated with a profound inflammatory response that is in part related to

the stress response.

Both in vitro and in vivo studies have demonstrated that Catecholamines

increase the expression of pro-inflammatory Cytokines such as Interleukin 6 (IL-6) [137] and high serum concentrations of IL-6 have been correlated with increased

morbidity after CPB in infants and children. [138] Therefore, techniques that can

improve the control of stress, and hence indirectly inflammation, have the potential

to improve outcome in pediatric cardiac surgery with CPB.

There are strong indications from the adult literature that both Epidural and

Spinal techniques may confer advantages in terms of hemodynamic response, stress

response, myocardial damage, [139] and markers of postoperative recovery. [140] Two

recent retrospective reports have described the use of regional techniques in

pediatric cardiac surgery and have suggested an outcome benefit, [141] but expert

commentaries have indicated that these are not techniques that should be adopted

without careful objective measurement of risk versus benefit. [142]

A Spinal catheter can be inserted before surgery, which provides high Spinal

anesthesia, the high-level blockade achieved intraoperatively can be confirmed by

the observation of bilateral dilated pupil (This blockade regress rapidly in the


41

postoperative period) and can also provide continuous regional analgesia in the

postoperative period.

CSA when evaluated against high-dose intravenous Opioid anesthesia in a

randomized controlled trial in infants and children aged up to 2 years undergoing

open heart surgery showed that overall plasma Norepinephrine concentrations were

significantly lower in the Spinal group. Also overall plasma Epinephrine

concentrations were significantly lower in the Spinal group. Plasma Cortisol

returned to baseline in the Spinal group at 24 h after cross clamp removal but

remained suppressed in the intravenous Opioid group. Furthermore, plasma Lactate,

a factor previously linked to increased morbidity and mortality in pediatric cardiac

surgery was lower in the Spinal group which could be due to either improved

cardiac output or enhanced peripheral perfusion. [143]

It is also noted that although Opioids can effectively eliminate stress responses

to non-bypass surgery, even very large doses of Opioids do not suppress the

increases in cortisol and catecholamines associated with pediatric CPB. [144] High-

dose Opioid techniques are often avoided in simple cardiac procedures to facilitate

early extubation while Spinal anesthesia has a relatively short duration and can

provide conditions for early extubation in suitable patients. [145] And so, according to

the previous factors, CSA is considered more effective than intravenous Opioid

anesthesia at controlling the stress response to CPB in pediatric patients undergoing

cardiac surgery as well as providing adequate postoperative analgesia. [146]


42

General Advantages of Neuraxial Blocks

In addition to the advantages of CSA technique itself, it was found that

Regional anesthesia, in general, provides many advantages over General anesthesia

(which off course also applies to CSA), these include improved survival, reductions

in risk of venous thrombo-embolism, myocardial infarction, bleeding complications,

pneumonia, respiratory depression, and renal failure. This was demonstrated in a

study that included 141 different trials with a total of 9559 patients which showed

that overall mortality was about one third less in the Neuraxial blockade group with

no clear difference between different surgical groups. The effect on total mortality

was not clearly lower in trials in which Neuraxial blockade was combined with

general anesthesia than in trials in which Neuraxial blockade was used alone. [147]

Neuraxial blockade result in reduction of the risk of deep vein thrombosis

(DVT) by almost half, there is one third fewer myocardial infarctions, the

requirement for a transfusion of two or more units of blood is reduced by about half,

the risk of developing Pneumonia is reduced, also the odds of respiratory depression

is reduced by 59%, while there was no clear difference in the proportional effects

with the use of concomitant general anesthesia. [147]

The benefits seen for Neuraxial blockade may be the result of multi-factorial

mechanisms, including altered coagulation, increased blood flow, improved ability

to breathe free of pain, and reduction in surgical stress responses. In particular,

major surgery induces a “stress response” that is substantially altered by Neuraxial

blockade but not by general anesthesia, the results suggest that these benefits are

principally due to the use of Neuraxial blockade rather than avoidance of general

anesthesia. Thus the key issue seems to be whether Neuraxial blockade is used or

not. [147]

Chapter 5 Contraindications &

Complications

Chapter 5 Contraindications & Complications

43

Contraindications for Continuous Spinal Anesthesia

The Contraindications for continuous Spinal anesthesia (CSA) are generally

those of neuraxial anesthesia as whole with some differences:

1-

Patient refusal, bleeding diathesis, elevated intracranial pressure and infection

at the site of injection. Although no preoperative screening tests are required for

healthy patients undergoing neuraxial blockade, coagulation studies and platelet

count should be checked when the clinical history suggests the possibility of a

bleeding diathesis. [148] CSA differs in that unlike other types of neuraxial blocks,

severe hypovolemia, severe stenotic valvular heart disease or ventricular outflow

obstruction are not considered a contraindication for CSA, in fact, it me be very

beneficial in these situations as mentioned in the previous chapter.

Absolute Contraindications:

2-

(A)

Relative and Controversial Contraindications:

Clinical findings in the back:

(B)

Which is detected by physical examination

of the back that may reveal important information, such as the presence of surgical

scars, scoliosis, skin lesions, and whether the spinous processes are palpable or not.

Dementia, Psychosis, or emotional instability:

(C)

As regional anesthesia

requires at least some degree of patient cooperation, and this may be difficult or

impossible with these patients so the decision needs to be individualized. Young

children also may similarly not be suitable for pure regional techniques.

Pre-existing neurological deficits or Demyelinating diseases: These

patients may report that their symptoms are worse following a block and it may be

impossible to discern effects or complications of the block from preexisting deficits


44

or unrelated exacerbation of preexisting disease. For these reasons, many

practitioners argue against neuraxial anesthesia in such patients.

(D) Sepsis or Bacteremia:

(E) Anticoagulant and Antiplatelet Therapies: Decision of whether a block

should be performed or not in the setting of

Neuraxial anesthesia in their presence could

theoretically predispose patients to hematogenous spread of the infectious agents

into the Epidural or Subarachnoid space, more discussion of the infective

complications of CSA will come later.

anticoagulants and antiplatelet agents

can be problematic. The general guidelines are as follow:

1- Long-Duration Anticoagulants (Vitamin K antagonists):

Such as Warfarin. The effects of Warfarin are not apparent until a

significant amount of biologically inactive factors are synthesized and is

dependent on coagulation factor half-life. The plasma half-life of Warfarin is

approximately 48 hours. The INR is most sensitive to the activities of factors

VII and X and is relatively insensitive to factor II activity. After temporary

interruption of Warfarin therapy, the initial decrease in the INR reflects the

decrease in factor VII levels and at least 5 days is required for recovery of the

other vitamin K-dependent clotting factors (II, IX, and X). [148]

2- Intermediate-Duration Anticoagulants:

Danaparoid is a low-molecular-weight heparinoid which has a plasma

half-life of 25 hours. Treatment with Danaparoid does not affect the aPTT, and

anticoagulant monitoring relies on anti-Xa measurements. Fondaparinux is a

synthetic anti-Xa inhibitor with stable pharmacokinetics, and a plasma half-life

of 15 to 18 hours. Although anticoagulant monitoring of Fondaparinux can be


45

done with anti-Xa levels, there is no proposed therapeutic range as with

LMWHs. [149]

3- Short-Duration Anticoagulants:

Intravenous Un-Fractionated Heparin (UFH) results in an immediate

anticoagulant effect, while subcutaneous UFH results in a 1 to 2 hour delay

before the onset of anticoagulant activity. The anticoagulant effect of UFH is

monitored with the Activated Partial Thromboplastin Time (aPTT), with a

target therapeutic aPTT of 1.5 to 2.0 times the baseline aPTT. Low-dose UFH

(5,000 IU twice-daily), typically used for prophylaxis against deep venous

thrombosis, does not prolong the aPTT, and laboratory monitoring is not

required.

LMWHs such as Enoxaparin are derived by chemical or enzymatic

depolymerization of UFH. The antithrombotic activity of LMWHs is primarily

through an anti-Xa effect and to a lesser extent an anti-IIa effect, whereas UFH

has the same anti-Xa and anti-IIa effects. [150] Many cases of Spinal hematoma

associated with neuraxial anesthesia followed the introduction of Enoxaparin

(Lovenox) in the United States in 1993. Many of these cases involved

intraoperative or early postoperative LMWH use, and several patients were

receiving concomitant antiplatelet medication. So if bloody needle or catheter

placement occurs, LMWH should be delayed until 24 hours postoperatively,

because this trauma may significantly increase the risk of Spinal hematoma. If

postoperative LMWH thromboprophylaxis will be utilized, catheters should be

removed 2 hours prior to the first LMWH dose. If already present, the catheter

should be removed at least 10 hours after a dose of LMWH and subsequent

dosing should not occur for another 2 hours. [151]


46

4- Oral Anti-Platelet Agents:

Inhibition of platelet adhesion, activation, and aggregation is a key

component of several major classes of available antiplatelet drugs. Ticlopidine

was the first drug, also Clopidogrel, a drug with a better safety profile, is now

common therapy in the management of coronary stent implantation. There is a

third class of antiplatelet drugs such as Abciximab but little literature is

available on these newer classes of antiplatelet drugs and their potential for

increasing the risks of neuraxial complications, however, their powerful effects

on platelet action must make their use a contraindication for neuraxial

anesthesia.

Urmey and Rowlingson reviewed the literature and concluded that

antiplatelet drugs by themselves appear not to represent an added significant

risk for development of Spinal hematoma in patients having Epidural or Spinal

anesthesia. [152] It is the combination of antiplatelet agents with other

anticoagulation drugs that may increase the risk of bleeding complications.

Careful preoperative assessment of the patient to identify complications that

might contribute to bleeding is important. In contrast, potent agents should be

stopped and neuraxial blockade should generally be administered only after

their effects have worn off. The waiting period depends on the specific agent:

for Ticlopidine (Ticlid) it is 14 days, Clopidogrel (Plavix) 7 days, Abciximab

(Rheopro) 48 hours, and Eptifibatide (Integrilin) 8 hours. [152]

5- Aspirin:

At low daily doses (30–300 mg), Aspirin inhibits production of

Thromboxane A2, a platelet aggregate stimulator and vasoconstrictor, while at

higher daily doses (1.5–2.0 g), it inhibits Prostacyclin. Thus, Aspirin increases

bleeding tendency and prolongs bleeding time for the entire lifetime of the


47

platelets (7–10 days), however it is no longer considered a contraindication for

neuraxial anesthesia. Non-Steroidal analgesics also can influence aggregation

of platelets, but this is limited in time to 1 to 3 days after stopping therapy. [153]

6- Direct Thrombin Inhibitors:

Lepirudin irreversibly binds to and inactivates circulating and clot-bound

Thrombin. Lepirudin has a plasma half-life of approximately 80 minutes and

is cleared mainly by renal mechanisms. Consequently, it should be avoided in

patients with impaired renal function. Monitoring of the anticoagulant effect of

Lepirudin is done with the aPTT, with a target aPTT of 1.5 to 2.0 times the

control value. Argatroban is a direct thrombin inhibitor that, unlike Lepirudin,

reversibly binds to and inactivates circulating and clot-bound thrombin.

Argatroban also differs from Lepirudin with a shorter plasma half-life (40-50

minutes) and elimination by hepatic mechanisms. Consequently, Argatroban is

the direct thrombin inhibitor of choice in patients with impaired renal function.

Its monitoring is done with the aPTT, with a target aPTT of 1.5 to 2.0 times the

control aPTT. [154]

Complications of Continuous Spinal Anesthesia

The complications of CSA include those generally associated with any

neuraxial block and complications related to the intrathecal catheter itself.

(A) General Complications: Coughing, discomfort, itching, nausea and vomiting

(IONV), hypotension, Post-Dural Puncture Headache (PDPH), infective

complications, aseptic meningitis, Spinal hematoma, Spinal cord or nerve root

injury.


48

(B) Catheter-Related Complications:

(A) General Complications

Cauda Equina syndrome, intrathecal

Granuloma, catheter migration, CSF leak, Spinal Myoclonus, Traumatic Syrinx

1- Coughing:

2-

Many patients are considered for the CSA technique because they

have poor respiratory function usually due to long standing chronic obstructive

airway disease and underlying chest infection, these patients may cough

spontaneously. Also the patient with acute abdominal pain requiring emergency

laparotomy and who has a concomitant active chest infection will be able to cough

on the operating table because their abdominal pain is relieved by Spinal anesthesia.

Patients who cough during surgery require the skills of a surgeon who is prepared to

tolerate a moving target.

Discomfort:

3-

There may be some discomfort during surgery under neuraxial

anesthesia, surgeons may occasionally touch the diaphragm during cholecystectomy

and other upper gastro-intestinal and colonic surgery. The diaphragm receives its

innervation from C3–5 and clearly these dermatomes are not blocked by Spinal

anesthesia resulting in a discomfort sensation for the patient, this may also be

caused by traction on the peritoneum. [155]

Itching:

4- Nausea and Vomiting: The incidence of IONV (Intraoperative nausea and

vomiting) during Spinal anesthesia for non-obstetric surgery ranges from 7% to

42%. [155] While the overall incidence of IONV during neuraxial anesthesia for

cesarean section is extremely variable (up to 80%) depending on the anesthetic

technique used and on the preventive and therapeutic measures taken. [156]

Some patients complain of minor itching of the nose and over the trunk

but they seldom require treatment.


49

One of the causes of IONV is insertion of a nasogastric tube that is probably

better being avoided unless needed badly. Other causes include Hypotension as it

may lead to cerebral hypoperfusion and brainstem ischemia that may activate the

circulatory, respiratory and vomiting centers in the medulla. [157] It is also speculated

that hypotension leads to gut ischemia and release of emetogenic substances such as

serotonin from the intestine. Strategies to prevent rather than treat hypotension

appear to be more likely to decrease the incidence of nausea and vomiting, this is

where CSA is superior to single-shot Spinal anesthesia. [158] Also excessive bowel

handling by the surgeon and administration of intrathecal Opioids can cause IONV.

Gentle handling of the bowel and administration of anti-emetics may reduce or

prevent IONV. [159]

5- Hypotension: It is the one of the commonest serious adverse reactions to

neuraxial anesthesia especially during caesarean section (due to maternal

physiological changes which makes this group more susceptible to hypotension).

Hypotension of sufficient severity and duration has the potential to induce loss of

consciousness, with the consequent risks of hypoxia through airway obstruction or

aspiration of stomach contents. Such severe and problematic hypotension is rare in

the normal population. But even a brief, mild hypotensive episode might be enough

to precipitate irretrievable hemodynamic collapse in the presence of certain medical

or obstetric conditions. Many would regard neuraxial anesthesia as contraindicated

in these circumstances, but modern anesthetic techniques such as CSA in our case

and anti-hypotensive regimens are forcing these views to be challenged. [160]

The mechanism for this hypotension is the blockade of sympathetic

vasoconstrictor fibers that emerge from Spinal segments T1-L2. Most if not all of

these should be blocked at least partially, because a block to light touch to T4 is

required to ensure comfort during anesthesia for abdominal surgeries if local


50

anesthetics alone are used. [160] Blockade to T6 seems adequate if a lipid soluble

intrathecal Opioid is included, but the upper end of such a block is still likely to

affect all sympathetic roots. The resultant loss of peripheral resistance and venous

pooling causes the cardiac output to fall.

The main risk factors that predispose to hemodynamic instability during

anesthesia in general and neuraxial anesthesia specifically are mentioned in Table

(02). First of all, whenever possible, any treatable risk factor should be corrected

before embarking on any form of anesthesia. For example, hypovolemia can be

anticipated and can be corrected with appropriate intravenous fluid therapy and for

patients with a reduced cardiac output due to cardiac disease they should have their

condition as much as possible medically optimized with regular cardiological

review. [161] Then for most of the untreatable or unpreventable factors, the benefits

of CSA come into action.

Risk Factor Etiology of Risk Factor

Preexisting Hypovolemia - Hemorrhage, Vomiting or Diarrhea.

Risk of Hemorrhage - Obstetric conditions such as Placenta previa. - Bloody operations as Orthopedic procedures or Vascular surgeries.

Reduced Cardiac Output States

- Cardiomyopathy - Valvular heart diseases such as tight aortic stenosis. - Antihypertensive drugs as β Blockers.

Increased Aorto-Caval Compression

- Multiple pregnancy or Polyhydramnios. - Obesity. - Intra-abdominal masses.

Table 01. The main risk factors for hemodynamic instability during neuraxial anesthesia. [161]


51

Epidural anesthesia is a well-established technique that pretty much enforces a

slow incremental induction, and thereby is associated with less frequent sudden and

severe hypotension than Spinal anesthesia. Techniques to prevent and treat

hypotension therefore usually work well. There is, however, a disadvantage and that

is it's relatively poor performance in preventing intra-operative visceral discomfort

when compared to Spinal anesthesia. Poor patient satisfaction scores, requirements

for intravenous analgesic supplementation, conversion to General anesthesia, and

complaints about intra-operative pain, are all more likely with Epidural than with

Spinal anesthesia. Another disadvantage is the highly unpredictable block level and

high incidence of patchy blocks. [162]

Single-shot Spinal anesthesia is obviously not an appropriate choice when

hemodynamic stability is vital. An audit was made in St. James’s University

Hospital in 2004 revealed an incidence of symptomatic hypotension of 35%

amongst healthy women having Spinal anesthesia for elective section, despite

prophylactic Ephedrine infusions. [162] However, for women where even a brief

episode of severe hypotension might, by significantly reducing coronary blood flow,

trigger hemodynamic collapse or dysrrhythmia, a gradual onset neuraxial block is

the sensible choice. [163]

Having earlier rejected Epidural anesthesia, continuous Spinal anesthesia

(CSA) may be the best choice in this situation. [164] There is a surprising variation in

total dose requirements with 0.5% hyperbaric Bupivacaine, ranging from 1.5 to 3.0

ml in patients of normal stature. Catheter and filter dead space is therefore

significant. Case reports have testified to the success of this technique in high risk

cardiac patients. [165] Introducing a T8 block over 30 min has in all cases preserved a

very stable blood pressure with minimal need for fluid boluses or vasoconstrictors.


52

Thus this regimen can be considered a very successful way to deliver high quality,

stable neuraxial anesthesia for operations in the lower half of the body. [166]

6- Post-Dural Puncture Headache (PDPH): It is another major complication of

neuraxial anesthesia and after diagnostic lumbar puncture which has been a vexing

problem for many patients. Clinical and laboratory research over the last 30 years

has shown that use of small-gauge needles, particularly of the pencil-point design, is

associated with a lower risk of PDPH than traditional cutting point needle tips

(Quincke-point needles).

The incidence of PDPH following Spinal anesthesia has been reported to vary

from 0.2 to 24% with a generally quoted incidence around 0.3%. [167] PDPH is more

frequently noted in pregnant women receiving Spinal anesthesia and in patients less

than 50 years of age. [168] There are certain demographic factors that seem to be

associated with risk of PDPH for reasons that are not well understood. Patient age is

a risk factor, with ages between 18 and 40 years showing the highest risk range. The

risk of PDPH at age 25 years is 3–4 times that at age 65 years while children

younger than 13 years rarely get PDPH. This is thought to be due to lower CSF

pressure in children. [169]

PDPHs do occur with increasing frequency in adolescents and are similar to the

risk seen in adults. [170] There is also significantly decreased frequency after age 60

years, which also may be related to lower CSF pressure. Female sex, regardless of

age, is also at higher risk for PDPH for unknown reasons. Women have

approximately twice the likelihood compared to men. [171] Race does not seem to be

a factor in development of PDPH. A history of chronic or recurrent headache has

been found in nearly 60% of those with PDPH. Previous history of PDPH is also a

risk factor for development of future headaches. [172]


53

Fig 23. Scanning electron micrograph of a dural puncture hole made by a 25G Quincke (cutting) needle. View is from the inner (intrathecal) side of the dura mater. Note the ‘open-tin-can’ configuration. [175]

Fig 24. Scanning electron micrograph of a dural puncture hole made by a 25G Quincke (cutting) needle. View is from the outer (Epidural) side of the dura. [175]

In addition to patient-related factors, there are several technical factors which

can affect the incidence of PDPH. The most important technical factor in

determining the incidence of PDPH is undoubtedly the size of the Dural hole

produced during puncture. There are two major relevant sub-topics to this issue:

needle size, and design of the needle point. There is a direct relationship of PDPH

to Spinal needle tip diameter. The larger the diameter of the needle, the more

frequent and more severe the headache.

There is an incidence of 80% with 16G needles versus 5% with 26G needles,

the overall incidence was 11% of 10,098 spinals in one large study. [173] Use of small

gauge pencil-point Spinal needles has reduced the incidence to about 0.02–1.5%. [174] This later factor is thought to be due to the smaller Dural hole produced by a

pencil-point needle compared with that produced by a cutting (Quincke) point

needle, resulting in less leakage of CSF. [175]

Any theory explaining PDPH must account for the relationship of the headache

to the loss of CSF. One theory states that the loss of CSF through a Dural hole

results in intracranial tension or traction on nerves and meningeal vessels. While the

bimodal theory suggests that there is a combination of both low CSF pressure and


54

resultant cerebral vasodilatation in reaction to the stretching of vessels. The amount

of CSF loss depends upon the size and shape of the Dural hole and the pressure

difference between the Subarachnoid and Epidural spaces. [176] The design of the

Spinal needle tip and orientation of a cutting needle bevel are both factors in

determining the rate of CSF loss. In one in-vitro study performed using human

postmortem thoracolumbar Dura Mater, the median loss of CSF volume in 5 min

was significantly less with a 22G Whitacre needle than with a 22G Quincke. [177]

There was a 21% reduction in leakage of CSF if the Quincke needle bevel was

parallel to the large axis of the vertebral column to bevel configuration. Cutting

fewer fibers of the Dura reduces the size of the Dural hole. Needle tips that stretch

Dural fibers should reduce the size of a resulting hole, in comparison to tips that cut

fibers, hence the rationale for using pencil-point needles rather than cutting needles

(Fig.23, 24, 25). [177]

In 1988, Dittmann and colleagues reported that Dural fibers are not uniformly

parallel, and that the thickness of the Dural sac is variable. They also described the

so-called "Tin Can Lid" phenomenon. [178]

Decreasing incidence of PDPH: This include using an angled approach to the

Subarachnoid space, such as a paramedian approach which is associated with a

lower incidence of PDPH. [179] Also avoiding multiple puncture holes in the Dura

Fig 25. Scanning electron micrograph of a dural puncture hole made by a 25G Whitacre (non-cutting) needle. View is from the inner (intrathecal) side of the dura mater. Note that the fibers are ‘torn’ rather than ‘cut’, resulting in an ellipsoidal configuration. [175]


55

Mater is also recommended to avoid PDPH. There is little advantage in using small

(25–29G) Quincke point needles compared with 24G pencil-point needles, so most

authorities suggest using smaller gauge, non-cutting needles.

In CSA, the risk of PDPH remains controversial, ranging from very low to over

30%. [181] And to reduce the risk of PDPH in CSA, small-gauge Spinal catheter

systems with different techniques of Dural perforation have been developed. [180]

Such as the over-needle group which showed a significantly shorter duration of

PDPH and lower maximum pain intensity than the through-needle group concluding

the potential benefit of the catheter over-needle technique for the reduction of the

duration and intensity of PDPH. [182]

7- Infective Complications: Although individual cases have been reported in the

literature, serious infections of the central nervous system (CNS) such as

arachnoiditis, meningitis, and abscess following Spinal or Epidural anesthesia are

rare. However, recent epidemiologic series from Europe suggest that the frequency

of infectious complications associated with neuraxial techniques may be

increasing.[183] Staphylococcus is the organism most commonly associated Epidural

abscess, often these infections occur in patients with impaired immunity.

Conversely, meningitis follows Dural puncture, and is typically caused by alpha-

hemolytic Streptococci, with the source of the organism the nasopharynx of the

performer. In order to reduce the risk of serious infection following neuraxial

blockade, the clinician must be familiar with the pathogenesis of CNS infections,

patient selection, and use of meticulous aseptic technique. [184,185]

Infectious complications may occur after any regional anesthetic techniques,

but are of greatest concern if the infection occurs around the Spinal cord or within

the Spinal canal. Possible risk factors include underlying sepsis, diabetes, depressed

immune status, steroid therapy, localized bacterial colonization or infection, and


56

chronic catheter maintenance. Bacterial infection of the central neural axis may

present as meningitis or cord compression secondary to abscess formation. [186] An

indwelling neuraxial catheter, though aseptically sited, may be colonized with skin

flora and consequently serve as a source for ascending infection to the Epidural or

intrathecal space. [187,188] .

8- Aseptic Meningitis: Aseptic meningitis following Spinal anesthesia can be the

consequence of a number of factors: trauma from the procedure itself, aggravation

of an underlying disease of the central nervous system (CNS), inflammatory

response to medication, or a foreign irritant (chemical) that had contaminated the

equipment used. Diagnosis is by exclusion, and clinical signs and CSF findings vary

greatly. [189] The onset of meningitis usually occurs 24-48h later, but may be delayed

by approximately 10 days. [190,191]

Since aseptic contamination of catheters can occur due to involuntary or faulty

maneuvers during their insertion, a study was made aiming to simulate such faulty

maneuvers and to study, by electron microscopy, the results of the contamination to

evaluate the potential danger. Also the tips of catheters used clinically were studied

to check for the presence of traces of possible involuntary contamination

(Fig.26).[192]

The distal segments of the catheters are easily contaminated with powder from

gloves (calcium carbonate) and disinfectant (Povidone-Iodine solution) when the tip

is held between the thumb and index finger. This is true for both catheters made of

pressed nylon resin and those made of polyamide, although the surface of the later is

smoother and seem to retain a smaller quantity of powder. Passage through the

lumen of the Spinal needle partially cleans the external surface of the catheter, but

not the tip, so that any impurities present can enter into the Subarachnoid space


57

Fig.26 Scanning electron micrographs of sterile catheters. (A) Surface of a Co-Span catheter touched with powdered gloves and not passed through the spinal needle (4000X). (B) Surface of a Co-Span catheter touched with powdered gloves and passed through the spinal needle. The reduction of calcium carbonate granules is remarkable (4000X). (C) The smear on the micro-Spinal surface is povidone-iodine (250X). (D) Tip of a micro-Spinal catheter touched with powdered sterile gloves and with povidone-iodine, note the grains of calcium carbonate included in povidone-iodine solution (4000X). (E) Spot of povidone-iodine on a Co-Span catheter (650X). (F) A Co-Span micro-catheter touched with powdered gloves dirtied with povidone-iodine. This is the only observed in which a granule of starch was present (800X). [192]

(Fig.27). Calcium Carbonate is an inert salt, only slightly hydro-soluble, and is

considered incapable of inducing aseptic inflammatory reactions. [192]

On the contrary, talcum, still used as powder for gloves, can induce an aseptic

inflammatory reaction (meningismus) in the Subarachnoid space. [193] However,

most packets of gloves bear the instruction "After donning, remove powder by

standard aseptic method". Also, very rarely the surface of a catheter can be

contaminated by starch grains, which can induce an aseptic inflammatory reaction in

the Epidural space and, probably, in the Subarachnoid space. [192]

Catheters also can easily be contaminated with Povidone-Iodine solution when

touched with gloves stained with this solution, but it does not seem that Povidone-

Iodine solution can induce meningeal reactions if the patient is not allergic to


58

Fig.27 Scanning electron micrographs of sterile catheters. (A) Tip of a Co-Span catheter touched with a powdered glove and passed through a 22-gauge spinal needle (300X). (B) The presence of numerous granules of calcium carbonate adhering to the edge of the tip (1500X). (C) and (D) A Micro-Spinal catheter tip appears to be very irregular, this might cause a narrowing of the lumen of the tip (350X). (E) A Co-Span catheter tip at 45° (190X). (F) A Co-Span catheter tip with manufacturing residue causing a partial obstruction of the lumen (190X). [192]

Iodine. The adhesion of these particles is facilitated by the irregularity of the

surfaces of Nylon catheters. [192]

Bacterial contamination of catheters may also occur even when the

anesthesiologist believes that he or she has operated under sterile conditions.

Fortunately, in most cases, septic contamination is without consequences. It is,

however, recommended that anesthetists, besides following the standard

precautions, should wash their hands and forearms before donning sterile gloves and

that they do not touch the tips of catheters. [192]


59

9- Spinal Hematoma: Its occurrence as a complication of neuraxial procedures is

extremely rare. Guidelines such as those discussed previously have been helpful in

providing guidance to practitioners who perform Spinal injections. A recent meta-

analysis of 613 cases of Spinal hematomas occurring during the period from 1826 to

1996 identified no clear etiology in nearly half the cases (43.6%). Only in 10.3% of

the cases was there a preceding Spinal injection or lumbar puncture. A total of 37

cases of hematoma were in patients who were either receiving anticoagulants or had

coagulation disorders. In the final analysis, only 4.2% (26 cases) of the patients

developed hematoma in proximal relationship to Spinal anesthesia or lumbar

puncture. [194] In another large review of Spinal hematomas, a total of over 1 million

cases of Epidural anesthetics and Subarachnoid blocks yielded only 20 cases of

hematoma. [195]

The location of neuraxial hematomas is almost universally in the Epidural

space, presumably because of the presence of significant Epidural venous plexuses.

Subarachnoid hematoma is exceedingly uncommon, as the cerebrospinal fluid

dilutes bleeding and vessels in the Subarachnoid space are not generally present. A

careful medication history should reveal anticoagulants taken before the procedure,

in addition, any patients experiencing weakness, back pain, sensory deficit, or

urinary retention after a Spinal injection should be carefully evaluated for a Spinal

hematoma or other neurologic injury. [195]

10- Spinal Cord or Nerve Root Injury: It is a documented complication for

neuraxial anesthesia as the needle can accidentally puncture the Spinal cord or

nerves, leading to injury. The risk for Spinal cord injury is highest during high

Epidural injections where there is a possibility that the needle cross the Epidural

space and enter intrathecally causing traumatic injury of the Spinal cord. In CSA

and Spinal injections, the needle intentionally enter the Subarachnoid space, so the


60

general guidelines indicate that the puncture is always made at L3-4 or below (in

adults) so as it's always below the level of termination of the Spinal cord. [196]

In addition, any pain experienced by the patient during insertion of the needle

or advancement of the catheter, specially burning pain in the lower limbs should

raise suspicion of an irritation of one or more of the Spinal nerve roots by the tip of

the needle or the catheter requiring withdrawal of the needle or catheter and

repositioning in the same level or in a whole different level. Also heavy sedation of

patients during the procedure should be avoided as it may lead to their being

unresponsive to pain that would otherwise warn the anesthetist that a nerve root is

being compromised, The Cauda Equina syndrome that has been said to be

associated with CSA will be discussed later with the Catheter-Related

complications.[196]

(B) Catheter-Related Complications

1- Cauda Equina Syndrome (CES): The CSA technique gained a big momentum

in the 1990s when micro-spinal catheters were introduced, but the technique was

surrounded by controversy when with the beginning of 1991, a few cases of sudden

onset of Cauda Equina syndrome (CES) following continuous Spinal anesthesia

with 5% Hyperbaric Lidocaine through micro-catheters have been reported [196]

leading to the banning of using Spinal micro-catheters (not the CSA technique

itself) by the Federal Drug Administration (FDA) in the USA. Denny questioned the

etiology of Cauda Equina syndrome and stated that "For a number of years and on

several occasions CSA has prevented patients from needing postoperative

ventilation and it would be unfortunate if this extremely useful technique was

abandoned due to its inappropriate application". In Denny’s opinion, the most likely

cause of Cauda Equina syndrome was maldistribution of hyperbaric Lidocaine when

injected slowly through a small end-hole catheter. In the absence of convincing


61

evidence that the Spinal micro-catheter itself was the cause of the Cauda Equina

syndrome, and as the availability of small bore micro-catheters increased, CSA

continued to be used in clinical practice outside of the USA. [197]

The ultrastructure of the Spinal Arachnoid and its relationship with the Spinal

nerve roots and Dural sac was studied to help explain the different patterns of local

anesthetic distribution in the Subarachnoid space after Spinal anesthesia, as well as

some neurological conditions associated with it. In scanning electron microscopy,

the Arachnoid appears composed of two different layers: a compact layer in direct

contact with the deep surface of the Dura Mater (Fig.28) and a trabecular layer that

lines the Dural sac internally. The later forms indentations or "Trabeculae" that

surround every Spinal nerve root (Fig.29) as well as the Spinal cord itself (Fig.30),

with most trabeculae reaching the pia mater. The Trabecular Arachnoid also

encloses the blood vessels that cross the Subarachnoid space. This layer has a

variable thickness of 10 to 60 nm offering little mechanical resistance. Trabecular

Arachnoid limits nerve root movement to a certain extent, holding each root in its

position within the Dural sac and in relation to other nerve roots. [198]

Fig.28 Human lamina arachnoid. Scanning electron microscopy. Magnification 180X Bar: 100 µm. [198]

Fig.29 Human spinal arachnoid trabecula. Trabecular arachnoid encircling motor and sensitive nerve roots at the entry site of nerve root cuffs. Scanning electron microscopy. Magnification 30X Bar: 1 µm. [198]


62

This distribution renders the Subarachnoid sac a compartmentalized space with

micro-compartments that may promote uneven distribution of local anesthetics

within the Dural sac. In those areas where the local anesthetic solution would not

mix (dilute) adequately with CSF, neurotoxic concentrations could be reached,

leading to nerve root damage. Anatomical factors may, in this way, help explain the

pathogenesis of neurological syndromes like CES. [198]

Lidocaine in Spinal anesthesia has been used since 1948, with a favorable

safety record. However, during the last two decades, an increasing number of

reports have identified Lidocaine as a possible cause of temporary and even

permanent neurological sequelae following Spinal anesthesia. [199]

In 1993, a new term, "Transient Neurological Toxicity" was introduced to

describe the development of pain in the buttocks and legs without motor symptoms,

following Spinal anesthesia with Lidocaine. Later, the terms "Transient Radicular

Irritation" [200] and "Transient Neurological Symptoms" [201] were also introduced. In

1937, Ferguson and Watkins described this complication. [202] But it was not until

the 1990s when CES was recognized in the context of continuous Spinal anesthesia.

In patients suffering from CES, the Cauda Equine (that bundle of long lumbar and

Fig.30 Human spinal arachnoid trabecula encircling the spinal cord. Scanning electron microscopy. Magnification 40X Bar: 100 µm. [198]

Fig.31 Diagram of a likely cause of temporary and permanent neurological complications following CSA. [198]


63

sacral nerves roots) is affected and produces pain, leg weakness, perineal sensory

loss, and urinary and fecal incontinence.

Possible mechanisms of injury include direct spine injury, intra-neural

injection, catheter-induced trauma, and Epidural hematoma. Another postulated

mechanism, as mentioned before, is poor mixing of hyperbaric local anesthetic with

cerebrospinal fluid (CSF) especially when large volumes of anesthetics are used (eg:

continuous techniques as CSA). [205]

The use of Spinal micro-catheters (28-32G) has also been blamed as a

contributor to the development of this syndrome. [203] Flow through these small

gauge catheters requires high perfusion pressure, which may promote the

accumulation of local anesthetic in the dependent parts of the Subarachnoid space.

This poor mixing of local anesthetic with CSF and the resulting higher

concentrations of anesthetics around sacral roots may contribute to nerve injury. As

a result, in 1992, the Food and Drug Administration (FDA) ordered the withdrawal

of small-bore Spinal catheters (less than 24G) from the US market. [204] Also it

seems clear at this time that the risk of developing TNS after Spinal anesthesia after

Lidocaine is significantly higher than after Bupivacaine, Prilocaine, or Procaine. [205]

Compartmentalized areas around nerve roots could lead to accumulation of

higher concentrations of local anesthetic in some parts of the Dural sac in detriment

of others, resulting in inadequate or asymmetric Spinal blocks (Fig.31). Moreover, if

a local anesthetic solution is inadvertently injected between the nerve root and its

own Trabecular Arachnoid layer, as the electron microscopic studies deem possible,

it could result in undiluted amounts of local anesthetics being in contact with such

Spinal nerve root. So it is theorized that CES may be the result of inadvertent

injection of local anesthetics into the perineural area enclosed by Trabecular

Arachnoid. [198]


64

Another factor which may contribute to nerve injury is the presence of 7.5%

glucose (used to produce hyperbaric solutions of local anesthetics) which affects

neuronal permeability and leads to edema and neuronal damage. However, its

impact on nerve damage has not been demonstrated in more recent studies despite

the fact that deleterious effects of hyperglycemia on neural function are well

documented. It has been suggested that the lack of a nerve sheath could make the

Cauda Equine particularly vulnerable to osmotic alterations and damage. [206]

In vitro experiments using cat rootlets demonstrated persistent block of some C

fibers after a brief exposure of rootlets to sucrose solutions with osmolalities as low

as 500 mOsm while the tonicity of 5% lidocaine in 7.5% glucose is 837 mOsm.

Considering the differences in volumes of CSF between the Subarachnoid space and

the compartment limited by the nerve root and its own Trabecular Arachnoid, it is

possible that relatively high concentrations of glucose after hyperbaric Spinal

blockade could reach certain nerve roots, with potential deleterious effects on

neuronal function. [207]

There are other factors not related to concentration of local anesthetics, such as

neuronal ischemia due to nerve fiber stretching that should also be considered. This

can occur, for example, during surgeries performed in lithotomy position that stretch

the nerve fibers of the Cauda Equine that may lead to ischemia and subsequent

nerve damage. In fact, a prospective study by Pollock and coworkers showed that

there was a significant difference in the incidence of TNS between patients having

surgery in the lithotomy position and those having surgery in the supine position.[208]

It has also been postulated that stretching of the Cauda Equina in the lithotomy

position could increase the vulnerability of the nerve roots to the effects of local

anesthetics.


65

On the basis of research in cadaver preparations, a glass "spine" model and

clinical experience in over 200 cases, it was suggested how these problems might be

avoided. [209] Since none of the patients reported in the literature to have suffered

neurological sequelae had experienced parasthesia at the time of placement of the

catheter, mechanical damage to the nerves had been discounted. The endoscopic

views shown did, however, demonstrate that all catheters inserted more than 30mm

developed loops (Fig.32, 33). It is readily envisaged therefore that such a loop could

accidentally surround a nerve root. When the looped catheter is removed the loop

could be tightened and cause direct nerve damage or nerve strangulation. [198]

Although nerve trauma is normally accompanied by severe pain and

parasthesia, in this situation none of the patients who subsequently developed Cauda

Equina Syndrome had full sensory and motor recovery of function prior to catheter

removal. There would therefore remain the possibility that some degree of local

analgesia was still present when the catheter was removed and that damage could

have occurred without the usual warning of pain or parasthesia. Although it has

been said that direct nerve damage should result in unilateral lesions it would be

Fig.32 The needle has passed the nerve (arrow). The indwelling catheter touches the anterior dura and is starting to bend. [198]

Fig.33 Looping of the catheter. This was inevitable when the distance inserted exceeded 30 mm. [198]


66

possible for a catheter loop to entrap more than one nerve root of the Cauda Equine

there by producing more complex symptoms. [198]

Also piercing and transneural placement of the micro-catheter can occur.

Under clinical circumstances this should be accompanied by pain and parasthesia.

However, there are reports in the literature of accidental injections into nerves which

are not immediately accompanied by pain and parasthesia, and indeed if pain and

parasthesia were a constant finding there would be little likelihood of such

injections occurring at all. So it is recommended that the catheter shouldn't be

introduced for more than 20 mm. In addition, all patients should be instructed to

report any abnormal sensations during needle or catheter placement. [198]

It should also be noted that where there is no structural damage to nerves,

permanent sequelae are rare. Indeed after therapeutic chemoneurolysis with alcohol

or phenol to treat intractable pain, nerve function commonly returns after a variable

amount of time. [210] Although there are reports of permanent damage following

regional nerve blocks such as ischial or brachial plexus block, it has been shown that

the extent of the lesions created depends not only on the actual local anesthetic used

but also on the manner in which the nerve damage is inflicted (by direct

subendoneural injection of the drugs). Additional support for this concept is

available from the retrospective analysis of a further 714 catheters used in Austria

since 1990 with no serious complications. [211]

So if the lack of complications is due to very careful handling of the catheters,

then it would be wise to limit the technique to only very experienced personnel. If it

is due to the use of 0.5% Bupivacaine, then Hyperbaric 5% Lidocaine should not be

used for the continuous micro-spinal route. Anyway, it would appear to make no

clinical sense to withdraw equipment which offers new horizons in anesthesia and

pain relief.


67

2- Intrathecal Granuloma: A documented complication for intrathecal catheters is

development of an intrathecal granuloma. It is mainly associated with prolonged

intrathecal infusions rather than limited duration intrathecal anesthesia. It is an

inflammatory mass that forms at the tip of an intrathecal catheter in response to the

administration of medications. [212] The first intrathecal granuloma was reported in

1991 in a patient who presented with paralysis. [213] The prevalence of intrathecal

granulomas is unknown. Reports have been published stating the prevalence is 0.1%

to 5% with others documenting that the rate is up to 50%. [214] Intrathecal

granulomas develop as a result of an inflammatory process.

Many theories have been postulated including reactions to the catheter itself

(Some investigators have suggested an allergy to silicone, but the absence of these

lesions in patients receiving Baclofen for spasticity does not support this hypothesis)

as well as impurities in the medications infused. The current thinking is that a

mitogen-activated protein kinase cascade that increases lymphocyte activity is the

underlying etiology for the formation of a Granuloma. [215] This cascade is believed

to be initiated by the presence of an intrathecal medication such as Morphine.

Granulomas are unrelated to infection and are sterile masses.

There have been no cases of granuloma reported with Sufentanil. However,

case reports have been published recently demonstrating that other medications may

be responsible for these lesions. Bupivacaine and Baclofen have been mentioned as

additional etiologies for intrathecal granuloma formation, although in these cases it

appears the patient had previously received high-concentration Opioids. [216,217] The

most controversial aspect in the etiology of granulomas involves the issue of

catheter placement.


68

Most granulomas have been reported in the area of the thoracic spine. This has

led many to conclude that catheters should be placed in the lumbar or cervical

region to avoid the site of most granulomas. This conclusion is based on

cerebrospinal fluid (CSF) flow in the region of the thoracic cord, where the flow

volume is reduced. The ventral thoracic Subarachnoid space has the longest region

of low-flow CSF within the entire intrathecal compartment. [218] This stagnation of

flow has been postulated to cause build-up of the offending drug, causing a peak in

both concentration and total dose.

Another theorized risk factor for intrathecal inflammatory mass is the use of a

single orifice catheter. [219] This is suspected because of increased concentration of

the medication in the cerebrospinal fluid near the single orifice as opposed to a

multi-orifice catheter in which the medication is spread throughout the locations of

the orifices in the intrathecal space.

Reviewing the reported cases of granuloma, the length of infusion of

medication until granuloma diagnosis ranges between 0.5 and 72 months with the

median being 24 months. [220] Therefore, the prevalence of intrathecal granulomas

may increase over time with prolonged infusion. So awareness of the condition and

clinical suspicion are the keys to successful management of this complication

3- Catheter Migration: It is also another serious complication that can result in

new onset of exacerbated axial or radicular irritation due to the migration of the tip

of the catheter. This may also result in decreased efficacy depending on the location

of the tip. Changes in symptoms can be sudden and abrupt or may slowly develop

over a long period of time. Aside from a thorough history and physical examination,

imaging is likely necessary to determine the cause of the change in symptoms.

Modalities to be considered include Computed Tomography, Magnetic Resonance,

or Side Port Myelography. [221,222]


69

4- Cerebrospinal Fluid Leak: There is a risk of cerebrospinal fluid leak any time

the intrathecal sac is accessed. Patients who have undergone lumbar puncture for a

neurologic workup are at risk for a low pressure cerebrospinal fluid headache as are

patients on the labor and delivery ward who have had accidental Dural punctures

during the Epidural placement. These complications related to cerebrospinal fluid

leak and low CSF pressure can also occur following placement of an intrathecal

drug delivery device. The leak can occur during the trial phase as well as the

permanent phase. Externalized and internalized pumps are at risk. In patients with

percutaneous catheters, the cerebrospinal fluid can travel through the same tract as

the catheter through the skin. In patients with implanted pumps, the CSF can collect

in a variety of locations, including along the catheter and in the pump pocket.

5- Spinal Myoclonus: It is characterized by focal involuntary muscular

contractions.[223]

6- Traumatic Syrinx: It is a rare event related to the introduction of a catheter into

the intrathecal space and the presence of its tip within the substance of the Spinal

canal. [224]

Table 02. General comparison between the four types of Neuraxial blocks. [147]

Conclusion

70

Conclusion

In conclusion to the discussion before, CSA was found to be a technique which

has marked advantages in many clinical circumstances, such as the patient with

multiple co-morbidities who needs lower body surgery in which general anesthesia

and other types of neuraxial blocks may have marked side effects on his condition.

CSA combine the benefits of both GA and other neuraxial blocks in the term of

better hemodynamic stability, minimal drug load, extension of anesthesia for long

operations, accurate control over the level of the block, decreasing incidence of

most intra and post-operative anesthesia related complications (pulmonary, cardiac,

CNS, embolic and hepatic complications) In addition, it can also be used for post-

operative analgesia.

But as any other interventional technique, there are complications for CSA

which must be understood regarding their incidence, etiology and management, in

order to be able to minimize them and manage them efficiently if they occur. Those

include complications of neuraxial blocks in general and other complications related

to insertion of intrathecal catheter during CSA. An important part of avoiding

complications is avoiding using CSA in the presence of a contraindication for it

such as a patient on active anticoagulation, as mentioned before there are guidelines

for using CSA with different types of anticoagulation which must be followed. And

also, it is recommended that this technique is performed by a senior anesthetist who

is experienced in neuraxial blocks.

Summary

71

Summary

CSA is a technique which has marked advantages in certain clinical

circumstances, particularly patients undergoing lower body surgery who are old in

age and/or have co-morbidities such as in the lungs (as COPD) and/or in the

cardiovascular system (as severe valvular heart lesions) who can benefit from

avoiding the risks of endotracheal intubation and general anesthesia and in the same

time avoiding rough hemodynamic changes associated with other types of neuraxial

blocks. CSA is effective for intra-operative anesthesia as well as for post-operative

analgesia, and also the intrathecal catheter can be used for long term intrathecal drug

administration to control chronic pain or spasticity.

Catheters used can be a micro-catheter (<24G) or a macro-catheter (>24G), the

micro-catheter allow using smaller spinal needles thus decreasing the incidence of

PDPH, but it present more technical difficulties. It can be inserted in a catheter-

over-the needle or a needle-over-the catheter fashion according to the CSA set used,

catheter-over-the needle type (Spinocath®) can decrease duration and severity of

PDPH by decreasing CSF leak from around the catheter.

A few guidelines for safe performance of CSA can be summarized as: review

its indication for every individual patient and assess the presence of any

contraindication, discuss it thoroughly with the patient explaining its advantages and

complications. Use strict aseptic measures, also the tip of the catheter shouldn't be

touched by the gloves or by the disinfecting material (as Betadine). Catheters should

be inserted in one of L3-4 or L4-5 spaces. Paramedian approach is preferred

especially in elderly patients. The catheter should only be inserted 2-3 cm maximum

in the subarachnoid space.

Summary

72

Any pain or parasthesia experienced by the patient during insertion of the

needle or threading of the catheter necessitates withdrawal of the catheter and the

needle as one unit and reintroduction in the same or another interspace. The catheter

injection port should be marked clearly "INTRATHECAL". Avoid using Lidocaine

or Hyperbaric Lidocaine intrathecally, Bupivacaine has the best established safety

profile in this setting. Finally, till now it is recommended that it is performed by a

senior anesthetist who is experienced in performing neuraxial anesthesia techniques.

References

References

73

(1) Jaitly VK, Kumar CM. Continuous spinal anaesthesia for laparotomy. Current Anaesthesia & Critical

Care 2009; 1: 5.

(2) Benonis JG, Habib AS. Ex utero intrapartum treatment procedure in a patient with arthrogryposis

multiplex congenita, using continuous spinal anesthesia and intravenous nitroglycerin for uterine

relaxation. International Journal of Obstetric Anesthesia 2008; 17: 53-56.

(3) Fuzier R, Murat O, Gilbert ML et al. Continuous spinal anesthesia for femoral fracture in two patients

with severe aortic stenosis. Ann Fr d’Anesth Re´anim 2006; 25: 528-531.

(4) Gosch UW, Hueppe M, Hallschmid M et al. Post-dural puncture headache in young adults, comparison of

two small-gauge spinal catheters with different needle design. British Journal of Anaesthesia 2005; 94:

657-661.

(5) Harold E., Stanley F., William H. Anatomy for Anaesthetists, eighth edition. 2004.

(6) Dean HP. Discussion of the relative value of inhalation and injection methods of inducing anaesthesia.

British Medical Journal 1907; 2: 869.

(7) Lemmon WT. A method for continuous spinal anesthesia. A preliminary report. Annals of Surgery 1940;

111: 141-144.

(8) Hingson RA, Edwards WB. Comprehensive review of caudal analgesia for anesthetists. Anesthesiology

1943; 4: 181-196.

(9) Tuohy EB. Continuous spinal anesthesia, its usefulness and technic involved. Anesthesiology 1944; 5:

142-148.

(10) Tuohy EB. Use of continuous spinal anesthesia utilizing the ureteral catheter technic. Journal of the

American Medical Association 1945; 128: 262-263.

(11) Cappe BE, Deutsche EV. A needle for fractional spinal anesthesia. Anesthesiology 1953; 14: 398-404.

(12) N.Calthorpe. The History of spinal needles: Getting to the point. Anaesthesia 2004; 59:1231-1241.

(13) Tuohy EB. Continuous spinal anesthesia, a new method of utilizing ureteral catheter. Surgery Clinics of

North America 1945; 25: 834-840.

(14) Tuohy EB. Continuous Spinal anesthesia, its usefulness and technique. Anesthesiology 1944; 5: 142-148.

(15) Dripps RD. A comparison of the malleable needle and catheter techniques for continuous spinal

anesthesia. New York Journal of Medicine 1950; 50: 1595-1599.

(16) Brown S. Fractional segmental spinal anesthesia in poor risk surgical patients. Anesthesiology 1952; 13:

416-428.

(17) N. M. Denny and D. E. Selander. Continuous Spinal Anaesthesia. British Journal of Anaesthesia 1998;

81:590-597.

(18) Giuffrida JG, Bizzarri DV, Masi R and colleagues. Continuous procaine spinal anesthesia fro cesarian

section. Anesthesia and Analgesia 1972; 51: 117-124.

(19) Kallos T, Smith TC. Continuous spinal anesthesia with hypobaric tetracaine for hip surgery in lateral

decubitus. Anesthesia and Analgesia 1972; 51: 76-62.

(20) Rao TLK, El-Etr AE. Anticoagulation following placement of extradural and subarachnoid catheters, an

evaluation of neurologic sequelae. Anesthesiology 1981; 55: 618:620.

References

74

(21) Denny N, Masters R, Pearson D et al. Postdural puncture headache after continuous spinal anesthesia.

Anesthesia and Analgesia 1987; 66: 791-794.

(22) Mahisekar UL, Winnie AP, Vasiroddy AO et al. Continuous Spinal anesthesia and postdural puncture

headache, a retrospective study. Regional Anesthesia 1991; 16: 101-111.

(23) Cohen S, Amar D, Pantuck EJ et al. Decreased incidence of headache after accidental dural puncture in

caesarean delivery patients receiving continuous intrathecal analgesia. Acta Anaesthesiologica

Scandinavica 1994; 38: 716-718.

(24) Liu N, Montefiore A, Kermarec N et al. Prolonged placement of spinal catheters does not prevent

postdural puncture headache. Regional Anesthesia 1993; 18: 110-113.

(25) Hampl KF, Schneider MC, Pargger H. A similar incidence of transient neurological symptoms after

spinal anesthesia with 2% and 5% lidocaine. Anesthesia and Analgesia 1996; 83: 1051-1054.

(26) Van Gessel E, Forster A, Gamulin Z. A prospective study of feasibility of continuous spinal anesthesia in

a university hospital. Anesthesia and Analgesia 1995; 80: 880-885.

(27) Horlocker TT, McGregor DG, Matsushige DK et al. Neurological complications of 603 continuous spinal

anesthetics using macro-catheter and micro-catheter techniques. Anesthesia and Analgesia 1997; 84:

1063-1070.

(28) Rigler ML, Drasner K, Krejcie TC et al. Cauda Equina syndrome after continuous spinal anesthesia.




1063-1070.

(30) Hurley RJ, Lambert DH. Continuous spinal anesthesia with a micro-catheter technique, preliminary

experience. Anesthesia and Analgesia 1990; 70: 97-102.

(31) De Anders J, Bellver J, Bolinches R. Comparison of continuous spinal anaesthesia using a 32G catheter

with anaesthesia using a single dose 24G atraumatic needle in young patients. British Journal of

Anaesthesia 1994; 73: 747-750.



1063-1070.

(33) Rigler ML, Drasner K, Krejcie TC et al. Cauda Equina syndrome after continuous spinal anesthesia.


(34) Schell RM, Brauer FS, Cole DJ et al. Persistent sacral nerve root defects after continuous spinal

anaesthesia. Canadian Journal of Anaesthesia 1991; 38: 908-911.

(35) FDA safety alert. Cauda Equina syndrome associated with use of small-bore catheters in continuous

spinal anesthesis. May 29, 1992.

(36) Thomas A. Edell and Somayaji Ramamurthy. Catheters for neural blockade, materials and design.

Techniques in Regional Anesthesia and Pain Management 1998; 2: 103-110.

(37) V.K. Jaitly, C.M. Kumar. Continuous spinal anaesthesia for laparotomy. Current Anaesthesia & Critical

Care 2009; 20: 60–64.

References

75

(38) Forster JG, Rosenberg PH, Niemi TT. Continuous spinal microcatheter (28 gauge) technique for arterial

bypass surgery of the lower extremities and comparison of ropivacaine with or without morphine for

postoperative analgesia. British Journal of Anaesthesia 2006; 97: 393-400.

(39) Kumar CM, CorbettWA, Wilson RG. Spinal anaesthesia with a micro-catheter in high-risk patients

undergoing colorectal cancer and other major abdominal surgery. Surgical Oncology 2008; 17: 73-79.

(40) U. W. Gosch, M. Hueppe, M. Hallschmid. Post-dural puncture headache in young adults, comparison of

two small-gauge spinal catheters with different needle design. British Journal of Anaesthesia 2005; 94

(5): 657-661.

(41) E. Alonso, F. Gilsanz, E. Gredilla and colleagues. Observational study of continuous spinal anesthesia

with the catheter-over-needle technique for cesarean delivery. International Journal of Obstetric

Anesthesia 2009; 18: 137-141.

(42) Tuohy EB. Continuous spinal anesthesia, its usefulness and technique involved. Anesthesiology 1942; 3:

522-529.

(43) Reddy LB, Pluma MH, Haschke RH et al. Neurotoxicity of intrathecal local anaesthetics in rabbits.

Anesthesiology 1985; 63: 364-370.

(44) Gaiser RP. Should intrathecal lidocaine be used in the 21st century? Journal of Clinical Anesthesia 2000;

12: 476-481.

(45) Thompson GE. This fight isn’t fair. Anesthesia and Analgesia 1994; 79: 608-609.

(46) De Jong RH. Last round for a heavyweight? Anesthesia and Analgesia 1994; 78: 3-4.

(47) Kung CC, Lin SY, Wu TJ. Clinical study of failure in continuous spinal anesthesia with bupivacaine.

Kaohsiung Journal of Medical Science 1998; 14: 486-491.

(48) Bevacqua BK, Cleary WF. Relative resistance to intrathecal local anaesthetics. Anesthesia and Analgesia

1994; 78: 1024-1026.

(49) Navano JL, Soria A, Herrera P, Montero R. Cauda equina syndrome after intradural anesthesia with

bupivacaine. Revista Espanola de Anesteisologia of Reanimacion 2001; 48: 337-339.

(50) Malinovsky JM, Charles F, Baudrimoh Pereon. Intrathecal ropivacaine in rabbits:, pharmacodynamics

and neurotoxicity study. Anesthesiology 2002; 97: 429-435.

(51) Hodgson PS, Liu SS. New developments in spinal anesthesia. Anesthesiology Clinics of North America

2000; 18: 235-249.

(52) A. Sell1, K. T. Olkkola, J. Jalonen and colleagues. Minimum effective local anaesthetic dose of isobaric

levobupivacaine and ropivacaine administered via a spinal catheter for hip replacement surgery. British

Journal of Anaesthesia 2005; 94 (2): 239-242.

(53) Kallos T, Smith TC. Continuous spinal anesthesia with hypobaric tetracaine for hip surgery in lateral

decubitus. Anesthesia and Analgesia 1972; 5: 766-773.

(54) Vercauteren MP, Geernaert K, Dohmen D and colleagues. Postoperative intrathecal patient controlled

analgesia with bupivacaine, sufentanil or a mixture of both. Anaesthesia 1998; 53: 1022-1027.

(55) J. G. Forster, P. H. Rosenberg, T. T. Niemi. Continuous spinal microcatheter (28 gauge) technique for

arterial bypass surgery of the lower extremities and comparison of ropivacaine with or without morphine

for postoperative analgesia. British Journal of Anaesthesia 2006; 97 (3): 393-400.

References

76

(56) Brian K. Bevacqua. Continuous spinal anaesthesia, what’s new and what’s not. Best Practice & Research

Clinical Anaesthesiology 2003 Vol. 17; No.3: 393-406.

(57) Ozalevli M, Cetin TO, Unlugenc H and colleagues. The effect of adding intrathecal magnesium sulphate

to bupivacaine–fentanyl spinal anaesthesia. Acta Anaesthesiologica Scandinavica 2005; 49: 1514-1519.

(58) Chanimov M, Cohen ML, Grinspun Y et al. Neurotoxicity after spinal anaesthesia induced by serial

intrathecal injections of magnesium sulphate. An experimental study in a rat model. Anaesthesia 1997;

52: 223-228.

(59) R. Arcioni, S. Palmisani, S. Tigano. Combined intrathecal and epidural magnesium sulfate

supplementation of spinal anesthesia to reduce post-operative analgesic requirements: a prospective,

randomized, double-blind, controlled trial in patients undergoing major orthopedic surgery. Acta

Anaesthesiologica Scandinavica 2007; 51: 482-489.

(60) H. Unlugenc, M. ozalevli, M. Gunduz. Comparison of intrathecal Magnesium, Fentanyl, or placebo

combined with bupivacaine 0.5% for parturients undergoing elective cesarean delivery. Acta


(61) Albright AL. Neurosurgical treatment of spasticity and other pediatric movement disorders. Journal Of

Child Neurology 2003;18 (1): 567-578.

(62) Ivanhoe CB, Francisco GE, McGuire JR and colleagues. Intrathecal baclofen management of poststroke

spastic hypertonia, implications for function and quality of life. Arch Physiotherapy Medicine &

Rehabilitation 2006;87: 1509-1515.

(63) Shawn Belverud, Alon Mogilner, and Michael Schulder. Intrathecal Pumps. The Journal of the American

Society for Experimental NeuroTherapeutics 2008 ; 5: 114-122.

(64) Krames ES. Intraspinal opioid therapy for chronic nonmalignant pain, current practice and clinical

guidelines. Journal Of Pain Symptomatic Management 1996; 11: 333-352.

(65) Hassenbusch SJ. Cost modeling for alternate routes of administration of opioids for cancer pain.

Oncology 1999; 13: 63-67.

(66) Smith TJ, Staats PS, Deer T and colleagues. Randomized clinical trial of an implantable drug delivery

system compared with comprehensive medical management for refractory cancer pain, impact on pain,

drug-related toxicity, and survival. Journal Of Clinical Oncology 2002; 20: 4040-4049.

(67) Karen H. Knight, Frances M. Brand and colleagues. Implantable Intrathecal Pumps for Chronic Pain,

Highlights and Updates. Croatian Medical Journal 2007; 48: 22-34.

(68) Kedlaya D, Reynolds L, Waldman S. Epidural and intrathecal analgesia for cancer pain. Best Practice

Research Clinical Anaesthesiology 2002; 16: 651-655.

(69) Smith TJ, Coyne PJ. How to use implantable intrathecal drug delivery systems for refractory chronic

pain. Journal Of Supportive Oncology 2003; 1: 73-76.

(70) Deer TR, Caraway DL, Kim CK, et al. Clinical experience with intrathecal bupivacaine in combination

with opioid for the treatment of chronic pain related to failed back surgery syndrome and metastatic

cancer pain of the spine. Spine Journal 2002; 2: 274-278.

(71) Gallagher RM. Epidural and intrathecal cancer pain management, prescriptive care for quality of life.

Pain Medicine 2004; 5: 235.

References

77

(72) Phillip C. Phan, Madhuri Are, Allen W. Burton. Neuraxial infusions. Techniques in Regional Anesthesia

and Pain Management 2005; 9: 152-160.

(73) Sutter PA, Gamulin Z & Forster A. Comparison of continuous spinal and continuous epidural anesthesia

for lower limb surgery in elderly patients. A retrospective study. Anaesthesia 1989; 44: 47-50.

(74) Lui N, Kuhlman N, Dalibon N et al. A randomized, double blinded comparison of intrathecal morphine,

sufentanil, and their combination versus IV morphine for postthoracotomy pain. Anesthesia and

Analgesia 2001; 92: 31-36.

(75) Michaloudis D, Petrou A, Bakos P et al. Continuous spinal anesthesia/analgesia for the perioperative

management of high-risk patients. European Journal of Anaesthesiology 2000; 18: 239-247.

(76) Brian K. Bevacqua. Continuous spinal anaesthesia, what’s new and what’s not. Best Practice & Research

Clinical Anaesthesiology 2003; 17: 393-406.

(77) Carpenter SL, Ceravolo AJ, Foldes FF, Continuous-drop subarachnoidal block with dilute procaine

solution for labor and delivery. American Journal of Obstetrics and Gynecology 1951; 61:1277-1284.

(78) Benedetti C, Tiengo M. Continuous subarachnoid analgesia in labour. Lancet1990; 335:225.

(79) Valerie A. Arkoosh, Craig M. Palmer and Colleagues. A randomized, double-masked, multicenter

comparison of the safety of Continuous Intrathecal Labor analgesia using a 28-gauge catheter versus

Continuous Epidural Labor analgesia. Anesthesiology 2008; 108:286–298.

(80) Steer PJ, Gatzoulis MA, Baker P. Heart Disease and Pregnancy. London. RCOG Press 2006.

(81) Pittard A, Vucevic M. Regional anaesthesia with a subarachnoid catheter for Caesarean section in a

parturient with aortic stenosis. Anaesthesia 1998; 53: 169-173.

(82) A. J. Byrne. Why bother with continuous spinal anaesthesia? Current Anaesthesia & Critical Care 2004;

15:236-238.

(83) Gurkan Turker, Alp Gurbet and Colleagues. Continuous spinal analgesia in parturients with severe heart

disease. International Journal of Obstetric Anesthesia 2007; 02:297-298.

(84) Whittaker S. Continuous Spinal analgesia/anaesthesia in Obstetrics. International Journal of Obstetric

Anesthesia 2007; 16:183.

(85) T. Okutomi & S. Kikuchi & K. Amano & Colleagues. Continuous spinal analgesia for labor and delivery

in a parturient with hypertrophic obstructive cardiomyopathy. Acta Anaesthesiologica Scandinavica 2002;

46:329–331.

(86) Pitkanen M, Rosenberg P, Silvanto M, Tuominen M. Haemodynamic changes during spinal anaesthesia

with slow continuous infusion or single dose of plain bupivacaine. Acta Anaesthesiologica Scandinavica

1992; 36: 526-529.

(87) M. Dresner, A. Pinder. Anaesthesia for caesarean section in women with complex cardiac disease, 34

cases using the Braun Spinocath® spinal catheter. International Journal of Obstetric Anesthesia 2009;

18:131–136.

(88) M. Van de Velde, W. Budts, E. Vandermeersch, B. Spitz. Continuous spinal analgesia for labor pain in a

parturient with aortic stenosis. International Journal of Obstetric Anesthesia 2003; 12:51–54.

(89) Arias F, Pineda J. Aortic stenosis and pregnancy. Journal of Reproductive Medicine 1978; 20: 229-232.

References

78

(90) Whitfield A, Holdcroft A. Anaesthesia for Caesarean section in patients with aortic stenosis, the case for

general anaesthesia. Anaesthesia 1998; 53: 107-112.

(91) Carvalho J. Cardiovascular disease in the pregnant patient. Textbookof Obstetric Anesthesia,

Philadelphia, Churchill Livingstone 2000: 553-564.

(92) Brian J E, Seifen A B, ClarkR B et al. Aortic stenosis, cesarean delivery, and epidural anesthesia. Journal

of Clinical Anesthesiology 1993; 5: 154-157.

(93) Lao T T, Sermer M, MaGee L et al. Congenital aortic stenosis and pregnancy, a reappraisal. American

Journal of Obstetrics and Gynecology 1993; 169: 540-545.

(94) Van Helder T, Smedstad K G. Combined spinal epidural anaesthesia in a primigravida with valvular heart

disease. Canadian Journal of Anaesthesiology 1998; 45: 488-490.

(95) Abboud T K, Zhu J, Sharp R, et al. The efficacy of intrathecal injection of Sufentanil using a microspinal

catheter for labor analgesia. Acta Anaesthesiologica Scandinavica 1996; 40: 210-215.

(96) Levin A, Datta S, Camann W R. Intrathecal Ropivacaine for labor analgesia, a comparison with B.

Anesthesia Analgesia 1998; 87: 624-627.

(97) Pitkins RM, Perloff JK, Koos BJ, Beall MH. Pregnancy and congenital heart disease. Annual

International Journal of Medicine 1990; 112: 445-454.

(98) Kandasamy R, Koh KF, Tham SL, Reddy S. Anaesthesia for caesarean section in a patient with

Eisenmenger’s syndrome. Singapore Medical Journal 2000; 41: 356-358.

(99) Foster JM, Jones RM. The anaesthetic management of the Eisenmenger syndrome. Annual Journal of

Royal College of Surgery in England 1984; 66: 353-355.

(100) Kandasamy R, Koh KF, Tham SL, Reddy S. Anaesthesia for caesarean section in a patient with

Eisenmenger’s syndrome. Singapore Medical Journal 2000; 41: 356-358

(101) Atanassoff P, Alon E, Schmid R, Pasch T. Epidural anesthesia for cesarean section in a patient with

severe pulmonary hypertension. Acta Anaesthesiologica Scandinavica 1989; 33: 75-77.

(102) Cole PJ, Cross MH, Dresner M. Incremental spinal anaesthesia for elective caesarean section in a

patient with Eisenmenger’s syndrome. British Journal of Anaesthesiology 2001; 86: 723-726.

(103) Shigeki Sakuraba, Shuya Kiyama et al. Continuous spinal anesthesia and postoperative analgesia for

elective cesarean section in a parturient with Eisenmenger’s syndrome. Journal of Anesthesia 2004;

18:300–303.

(104) Reimold S C, Rutherford J D. Peripartum cardiomyopathy. Northern England Journal of Medicine

2001; 344: 1629–1630.

(105) Ranasinghe J S, Ranasinghe N, Bailur N, Gallardo C. Use of continuous spinal anesthesia for an

urgent cesarean delivery. American Journal of Anesthesiology 2001; 28: 341-343.

(106) I. A. Velickovic, C. H. Leicht. Continuous spinal anesthesia for cesarean section in a parturient with

severe recurrent peripartum cardiomyopathy. International Journal of Obstetric Anesthesia 2004; 13:40-

43.

(107) Toshiyuki Okutomi, Miwako Saito et al. Spinal anesthesia using a continuous spinal catheter for

cesarean section in a parturient with prior surgical correction of scoliosis. Journal of Anesthesia 2006;

20:223–226.

References

79

(108) Mollmann M, Cord S, Holst D, et al. Continuous spinal anaesthesia or continuous epidural

anaesthesia for post-operative pain control after hip replacement? European Journal of Anaesthesiology

1999; 16(7): 454-461.

(109) Berggren D, Gustavsson Y, Eriksson B, et al. Postoperative confusion after anesthesia in elderly

patients with femoral neck fractures. Anesthesia Analgesia 1987; 66: 497-504.

(110) Juelsgaard P, Sand NPR, Felsby S, et al. Perioperative myocardial ischaemia in patients undergoing

surgery for fractured hip randomized to incremental spinal, single-dose spinal or general anaesthesia.

European Journal of Anaesthesiology 1998; 15: 656-663.

(111) Lim HH, Ho KM, Choi WY, et al. The use of intravenous atropine after a saline infusion in the

prevention of spinal anesthesia-induced hypotension in elderly patients. Anesthesia Analgesia 2000; 91:

1203-1206.

(112) McCrae AF, Wildsmith JAW. Prevention and treatment of hypotension during central neural block.

British Journal Anaesthesia 1993; 70: 672-680.

(113) Buggy D, Higgins P, Moran C, et al. Prevention of spinal anesthesia-induced hypotension in the

elderly, comparison between preanesthetic administration of crystalloids, colloids and no prehydratation.

Anesthesia Analgesia 1997; 84: 106–110.

(114) Asehnoune K, Larousse E, Tadie´ JM, et al. Small dose bupivacaine-sufentanil prevents cardiac

output modifications after spinal anesthesia. Anesthesia Analgesia 2005; 101: 1512-1515.

(115) Aditya Nath Shukla, Wei Tsung Teoh & Usha Rajah. Bilateral Total Hip Replacement in a patient

with severe Ankylosing Spondilitis utilizing Continuous Spinal Anaesthesia. The Internet Journal of

Anesthesiology 2007; Volume 14, Number 2.

(116) Vincent Minville, Olivier Fourcade and Colleagues. Spinal Anesthesia using Single Injection small-

dose Bupivacaine versus Continuous Catheter Injection techniques for surgical repair of hip fracture in

elderly patients. Anesthesia Analgesia 2006; 102:1559-1563.

(117) K. Maurer, J.M. Bonvini, G. Ekatodramis and Colleages. Continuous spinal anesthesia/analgesia vs.

single-shot spinal anesthesia with patient-controlled analgesia for elective hip arthroplasty. Acta


(118) Mehmet Turan Inal, Alkin Colak et al. Successful use of Continuous Spinal Anesthesia technique

for Femoro-Popliteal by-pass in a patient with congestive heart failure and pulmonary hypertension. The

Internet Journal of Anesthesiology 2007; Volume 13, Number 2.

(119) Klimscha W, Weinstabl C, Ilias W, et al. Continuous spinal anesthesia with a microcatheter and

low-dose bupivacaine decreases the hemodynamic effects of centroneuraxis blocks in elderly patients.

Anesth Analg 1993; 77: 275-280

(120) Schnider TW, Mueller-Duysing S, Johr M, Gerber H. Incremental dosing versus single-dose spinal

anesthesia and hemodynamic stability. Anesthesia Analgesia 1993; 77: 1174-1178.

(121) Nienaber CA, Fattori R, Lund G, et al: Nonsurgical reconstruction of thoracic aortic dissection by

stent-graft placement. National English Journal of Medicine1999; 340: 1539-1545.

(122) Safi HJ, Miller CC 3rd. Spinal cord protection in descending thoracic and thoracoabdominal aortic

repair. Annual Thoracic Surgery 1999; 67: 1937-1939.

References

80

(123) Shin Su Ki and Andrew B. Leibowitz. Endovascular thoracic aortic aneurysm repair using a single

catheter for spinal anesthesia and cerebrospinal fluid drainage. Journal of Cardiothoracic and Vascular

Anesthesia Vol 15; No 1 (February) 2001:88-89.

(124) Ö. Gülçin, Mensure Kaya, T. Gonca and colleagues. Continuous spinal anaesthesia and analgesia in

high-risk patients undergoing abdominal surgery. Indian Journal of Surgery, April 2006, Volume 68;

Issue 2: 73-79.

(125) V.K. Jaitly, C.M. Kumar. Continuous spinal anaesthesia for laparotomy. Current Anaesthesia &

Critical Care 20 (2009); 62: 60-64.

(126) Chandra M. Kumar, William A. Corbett, Robert G. Wilson. Spinal anaesthesia with a micro-

catheter in high-risk patients undergoing colorectal cancer and other major abdominal surgery. Journal Of

Surgical Oncology 2008; 17: 73-79.

(127) Michaloudis D, Petrou A, Bakos P et al. Continuous spinal anaesthesia/analgesia for the

perioperative management of high-risk patients. European Journal of Anaesthesiology 2000; 17: 239-247.

(128) Niemi L, Pitkanen MT, Tuominen MK et al. Comparison of intrathecal fentanyl infusion with

intrathecal morphine infusion or bolus for postoperative pain relief after hip arthroplasty. Anesthesia and

Analgesia 1993; 77: 126-130.

(129) Hall JC, Tarala RA, Hall JL, Mander J. A multivariate analysis of the risk of pulmonary

complications after laparotomy. Chest 1991; 99: 923-927.

(130) Wong DH, Weber EC, Schell MJ et al. Factors associated with postoperative pulmonary

complications in patients with severe chronic obstructive pulmonary disease. Anesthesia and Analgesia

1995; 80: 276-284.

(131) Noda K, Ryo K, Nakamoto A. A case of emergency surgery in apatient with bronchial asthma under

continuous spinal anesthesia. Masui 2003; 52: 1121-1123.

(132) Chaney MA. Side effects of intrathecal and epidural opioids. Canadian Journal of Anaesthesia 1995;

42: 891-903.

(133) D. Michaloudis, O. Fraidakis, A. Petrou. Continuous Spinal Anesthesia/Analgesia for perioperative

management of morbidly obese patients undergoing laparotomy for gastroplastic surgery. Journal of

Obesity Surgery 2000; 10: 220-229.

(134) Gruber EM, Laussen PC, Casta A et al. Stressresponse in infants undergoing cardiac surgery, A

randomized study of fentanyl bolus, fentanyl infusion, and fentanyl-midazolam infusion. Anesthesia

Analgesia 2001; 92: 882-890.

(135) Anand KJ, Hansen DD, Hickey PR. Hormonal–metabolic stress responses in neonates undergoing

cardiac surgery. Anesthesiology 1990; 73: 661-670.

(136) Anand KJ, Hickey PR. Halothane-morphine compared with high-dose sufentanil for anesthesia and

postoperative analgesia in neonatal cardiac surgery. National English Journal of Medicine 1992; 326: 1-

9.

(137) Briest W, Elsner C, Hemker J et al. Norepinephrineinduced expression of cytokines in isolated

biventricular working rat hearts. Molecular Cellular Biochemistry 2003; 245: 69-76.

References

81

(138) Sondergaard SR, Ostrowski K, Ullum H et al. Changes in plasma concentrations of interleukin-6

and interleukin-1 receptor antagonists in response to adrenaline infusion in humans. European Journal of

Applied Physiology 2000; 83: 95-98.

(139) Loick HM, Schmidt C, Van Aken H et al. High thoracic epidural anesthesia, but not clonidine,

attenuates the perioperative stress response via sympatholysis and reduces the release of troponin T in

patients undergoing coronary artery bypass grafting. Anesthesia Analgesia 1999; 88: 701-709.

(140) Priestley MC, Cope L, Halliwell R et al. Thoracic epidural anesthesia for cardiac surgery: The

effects on tracheal intubation time and length of hospital stay. Anesthesia Analgesia 2002; 94: 275-282.

(141) Hammer GB, Ngo K, Macario A. A retrospective examination of regional plus general anesthesia in

children undergoing open heart surgery. Anesthesia Analgesia 2000; 90: 1020-1024.

(142) Bosenberg A. Neuraxial blockade and cardiac surgery in children. Paediatric Anaesthesia 2003; 13:

559-560.

(143) Nigel Humphreys, Simon M. Bays, Andrew J. Parry et al. Spinal Anesthesia with an Indwelling

Catheter reduces the Stress Response in Pediatric Open Heart Surgery. Anesthesiology 2005; 103: 1113-

1120.

(144) Anand KJ, Hickey PR. Halothane-morphine compared with high-dose sufentanil for anesthesia and

postoperative analgesia in neonatal cardiac surgery. National English Journal of Medicine 1992; 326: 1-9.

(145) Duncan HP, Cloote A, Weir PM et al. Reducing stress responses in the pre-bypass phase of open

heart surgery in infants and young children, A comparison of different fentanyl doses. British Journal of

Anaesthesiology 2000; 84: 556-564.

(146) Lee TW, Grocott HP, Schwinn D et al. High spinal anesthesia for cardiac surgery, Effects on beta-

adrenergic receptor function, stress response, and hemodynamics. Anesthesiology 2003; 98: 499-510.

(147) Anthony Rodgers, Natalie Walker, S Schug et al. Reduction of postoperative mortality and

morbidity with epidural or spinal anaesthesia, results from overview of randomised trials. British Medical

Journal 2000; 321: 1-12.

(148) Shields RC, McBane RD, Kuiper JD. Efficacy and safety of intravenous phytonadione (vitamin K1)

in patients on long-term oral anticoagulant therapy. Mayo Clinic Proc 2001; 76: 260-266.

(149) Turpie AG, Gallus AS, Hoek JA. Pentasaccharide Investigators. A synthetic pentasaccharide for the

prevention of deep-vein thrombosis after total hip replacement. National English Journal of Medicine

2001; 344: 619-625.

(150) Hirsh J, Raschke R. Heparin and low-molecular-weight heparin, the Seventh ACCP Conference on

Antithrombotic and Thrombolytic Therapy. Chest 2004; 126: 188-203.

(151) G. Edward Morgan, Jr. Maged S. Mikhail, Michael J. Murray. Clinical Anesthesiology, 4th Edition

2007.

(152) Urmey WF, Rowlingson J. Do antiplatelet agents contribute to the development of perioperative

spinal hematoma? Regional Anesthesia and Pain Medicine 1998; 23: 146-151.

(153) Douglas J. Allen, Sang H. Chae-Kim and colleagues. Risks and complications of neuraxial

anesthesia and the use of anticoagulation in the surgical patient. Baylor University medical center

(BUMC) proceedings 2002; 15: 369-373.

References

82

(154) James D. Douketis & Francesco Dentali. Managing anticoagulant and antiplatelet drugs in patients

who are receiving neuraxial anesthesia and epidural analgesia: a practical guide for clinicians. Techniques

in Regional Anesthesia and Pain Management 2006; 10: 46-55.

(155) Rodgers A. A retrospective meta-analysis of 141 studies involving 9,559 patients, reported in

December 2000. British Medical Journal 2000; 321: 1493-1497.

(156) Carpenter R L, Caplan R A, Brown D L. Incidence and risk factors for side effects of spinal

anesthesia. Anesthesiology 1992; 76: 906-916.

(157) Pan P H, Moore C H. Comparing the efficacy of prophylactic metoclopramide, ondansetron and

placebo in cesarean section patients given epidural anesthesia. Journal of Clinical Anesthesia 2001; 13:

430-435.

(158) Borgeat A, Ekatodramis G, Schenker C A. Postoperative nausea and vomiting in regional

anesthesia. Anesthesiology 2003; 98: 530-547.

(159) M. Balki, J. C. A. Carvalho. Intraoperative nausea and vomiting during cesarean section under

regional anesthesia. International Journal of Obstetric Anesthesia 2005; 14: 230-241.

(160) Kumar CM, Corbett WA, Wilson RG. Spinal anaesthesia with a micro-catheter in high-risk patients

undergoing colorectal cancer and other major abdominal surgery. Surgery & Oncology Journal 2008; 17:

73-79.

(161) Russell I. Assessing the block for caesarean section (Editorial). International Journal Obstetric

Anesthesia 2001; 10: 83-85.

(162) Bamber JH, Dresner M. Aort-ocaval compression in pregnancy, the effect of changing the degree

and direction of lateral tilt on maternal cardiac output. Anesthesia Analgesia 2003; 97(1): 256-258.

(163) Martin Dresner. Haemodynamic stability and regional anaesthesia for caesarean section. Current

Anaesthesia & Critical Care 2004; 15: 262-269.

(164) Nishikawa K, Yoshida S, Shimodate Y, Igarashi M et al. A comparison of spinal anesthesia with

small-dose lidocaine and general anesthesia with fentanyl and propofol for ambulatory prostate biopsy

procedures in elderly patients. Journal of Clinical Anesthesia 2007; 19: 25-29.

(165) Christian S. Meyhoff, Christian Haarmark. Is it possible to predict hypotension during onset of

spinal anesthesia in elderly patients? Journal of Clinical Anesthesia 2009; 21:23-29

(166) Velickovic IA, Leicht CH. Continuous spinal anesthesia for cesarean section in a parturient with

severe recurrent peripartum cardiomyopathy. International Journal of Obstetric Anesthesia 2004; 13:40-

43.

(167) Martin Dresner. Haemodynamic stability and regional anaesthesia for caesarean section. Current

Anaesthesia & Critical Care 2004; 15:262-269

(168) Halpern S & Preston R. Post-dural puncture headache and spinal needle design. Anesthesiology

1994; 81: 1376-1383.

(169) Neal JM. Update on post dural puncture headache, techniques in Regional Anaesthesia and Pain

Management 1998; 2: 202-210.

(170) Davignon KR, Dennehy KC. Update on postdural puncture headache. International Anesthesiology

Clinical Journal 2002; 40: 89-102.

References

83

(171) Ylonen P, Kokki H. Epidural blood patch for management of postdural puncture headache in

adolescents. Acta Anaesthesiologica Scandinavica 2002; 46: 794-798.

(172) Kuntz KM, Kokmen E, Stevens JC and colleagues. Post-lumbar puncture headaches, experience in

501 consecutive procedures. Neurology 1992; 42: 1884-1887.

(173) Clark JW. Substance P concentration and history of headache in relation to postlumbar puncture

headache, towards prevention. Journal of Neurology, Neurosurgery & Psychiatry 1996; 60: 681-683.

(174) Vandam LD, Dripps RD. Long term follow-up of patients who received 10,098 spinal anesthetics,

Syndrome of decreased intracranial pressure (headache and ocular and auditory difficulties). Journal of

the American Medical Association 1956; 161: 586-591.

(175) Ross BK, Chadwick HS, Mancuso JJ. Sprotte needle for obstetric anaesthesia, decreased incidence

of post dural puncture headache. Regional Anaesthesia 1992; 17: 29-33.

(176) Robert L. Frank. Lumbar puncture and postdural puncture Headaches, implications for the

emergency physician. The Journal of Emergency Medicine 2008; 35 (2):149-157.

(177) Buettner J, Wresch KP, Klose R. Post-dural puncture headache, comparison of 25-Gauge Whitacre

and Quincke needles. Regional Anaesthesia 1993; 18: 166-169.

(178) Dittman M, Scha¨fer HG, Ulrich J, Taylor WB. Anatomical re-evaluation of lumbar dura mater with

regard to postspinal headache. Effect of dural puncture. Anaesthesia 1988; 43: 635-637.

(179) Reina MA, de Leon-Casasola OA, Lo`pez A et al. An in vitro study of dural lesions produced by

25-gauge Quincke and Whitacre needles evaluated by scanning electron microscopy. Regional

Anaesthesia and Pain Medicine 2000; 25: 393-402.

(180) Ready LB, Cuplin S, Haschke RH and colleagues. Spinal needle determinants of rate of transdural

fluid leak. Anaesthesia and Analgesia 1989; 69: 457-460.

(181) Kenneth D. Candido, Rom A. Stevens. Post-dural puncture headache, pathophysiology, prevention

and treatment. Best Practice & Research Clinical Anaesthesiology 2003; Vol. 17 (No.3): 451-469.

(182) Horlocker TT, McGregor DG, Matsushige DK and colleagues. Neurologic complications of 603

consecutive continuous spinal anesthetics using macrocatheter and microcatheter techniques,

Perioperative Outcomes Group. Anesthesia Analgesia Journal 1997; 84: 1063-1070.

(183) U. W. Gosch1, M. Hueppe1, M. Hallschmid and colleagues. Post-dural puncture headache in young

adults, comparison of two small-gauge spinal catheters with different needle design. British Journal of

Anaesthesia 2005; 94 (5): 657-661.

(184) Terese T. Horlocker, Denise J. Wedel. Infectious complications of regional anesthesia. Best Practice

& Research Clinical Anaesthesiology 2008; 22 (3):451–475.

(185) Wedel DJ & Horlocker TT. Regional anesthesia in the febrile or infected patient. Regional

Anesthesia and Pain Medicine 2006; 31:324–333.

(186) Anne Ptaszynski, Marc Huntoon. Complications of spinal injections. Techniques in Regional

Anesthesia and Pain Management 2007; 11:122-132.

(187) Moen V, Dahlgren N & Irestedt L. Severe neurological complications after central neuraxial

blockades in Sweden 1990–1999. Anesthesiology 2004; 101:950–959.

References

84

(188) Shaul Cohen, Christine W. Hunter, Ashraf Sakr et al. Meningitis following intrathecal catheter

placement after accidental dural puncture. International Journal of Obstetric Anesthesia 2005; 10: 171.

(189) Horlocker TT, McGregor DG, Matsushige DK et al. Neurologic complications of 603 consecutive

continuous spinal anesthetics using macrocatheter and microcatheter techniques. Anesthesia Analgesia

1997; 84: 1063-1070.

(190) Stephan Jolles WA, Sewell C, Leighton C. Drug-induced aseptic meningitis, Diagnosis Manage

Drug Safety 2000; 22(3): 215-226.

(191) T. Kasai, K. Yaegashi, M. Hirose. Aseptic meningitis during combined continuous spinal and

epidural analgesia. Acta Anaesthesiologica Scandinavica 2003; 47: 775-776.

(192) Felice Ramajoli, Donatella De Amici, and Annalia Asti. Scanning electron microscopy study on

Spinal Micro-catheters. Anesthesia Analgesia 1999; 89:1011–1016.

(193) Green MA, Lam Y, Moss F. Starch, gloves and extradural catheters. British Journal of Anaesthesia

1995; 75:768-770.

(194) Kreppel D, Antoniadis G, Seeling W. Spinal hematoma, a literature survey with meta-analysis of

613 patients. Neurosurgery Review 2003; 26: 1-49.

(195) Tryba M. Epidural regional anesthesia and low molecular heparin. Anesthesia and Intensive

medicine Journal 1993; 28: 179-181.

(196) Lee DS, Bui T, Ferrarese J and colleagues. Cauda Equina syndrome after incidental total spinal

anesthesia with 2% lidocaine. Journal of Clinical Anesthesia 1998; 10: 66-69.

(197) Denny NM. Continuous spinal anaesthesia and cauda equina syndrome. Anaesthesia 1995; 50: 474.

(198) Miguel Angel Reina, Fabiola Maches, Andrés López and colleagues. The ultrastructure of the spinal

arachnoid in humans and its impact on spinal anesthesia, cauda equina syndrome, and transient

neurological syndrome. Techniques in Regional Anesthesia and Pain Management 2008; 12: 153-160.

(199) Schell RM, Brauer FS, Cole DJ, et al. Persistent sacral nerve root deficits after continuous spinal

anaesthesia. Canadian Journal of Anaesthesia 1991; 38: 908-911.

(200) Schneider M, Ettlin T, Kaufmann M, et al. Transient neurologic toxicity after hyperbaric

subarachnoid anesthesia with 5% lidocaine. Anesthesia Analgesia 1993; 76: 1154-1157.

(201) Salmela L, Aromma U. Transient radicular irritation after spinal anaesthesia induced with

hyperbaric solutions of cerebrospinal fluid diluted lidocaine 50 mg/ml or mepivacaine 40 mg/ml or

bupivacaine 5 mg/ml. Acta Anaesthesiologica Scandinavica 1998; 42: 765-769.

(202) Ferguson FH, Watkins KH. Paralysis of the bladder and associated neurological sequelae of spinal

anesthesia (cauda equina syndrome). British Journal of Surgery 1937; 25: 735-752.

(203) Navarro JL, Soria A, Herrera P, et al. Cauda equina syndrome after intradural anesthesia with

bupivacaine. Rev Esp Anestesiol Reanim 2001; 48: 337-339.

(204) Food and Drug Administration Safety Alert: Cauda equina syndrome associated with the use of

small-bore catheters in continuous spinal anesthesia. May 29, 1992.

(205) Zaric D, Christiansen C, Pace NL, et al. Transient neurologic symptoms after spinal anesthesia with

lidocaine versus other local anesthetics, a systematic review of randomized, controlled trials. Anesthesia

Analgesia 2005; 100: 1811-1816.

References

85

(206) Hampl KF, Schneider MC, Thorin D, et al. Hyperosmolarity does not contribute to transient

radicular irritation after spinal anesthesia with hyperbaric 5% lidocaine. Regional Anesthesia and Pain

Medicine 1995; 20: 363-368.

(207) King JS, Jewett DL, Sundberg HR. Differential blockade of cat dorsal root C fibers by various

chloride solutions. Journal of Neurosurgery 1972; 36: 569-583.

(208) Pollock JE, Neal JM, Stephenson CA, et al. Prospective study of the incidence of transient radicular

irritation in patients undergoing spinal anesthesia. Anesthesiology 1996; 84: 1361-1367.

(209) W. K. Ilias, W. Klimscha, G. Skrbensky. Continuous microspinal anaesthesia, another perspective

on mechanisms inducing cauda equina syndrome. Anaesthesia 1998; 53: 618-623.

(210) Bridenbough PO, eds. Neural Blockade in Clinical Anesthesia and Management of Pain.

Philadelphia, Lippincott 1980: 637-650.

(211) Hopwood MB. Statistics, can we prove an association for a rare complication? Regional Anesthesia

1993; 18: 428-433.

(212) Follett KA. Intrathecal analgesia and catheter-tip inflammatory masses. Anesthesiology 2003; 99: 5-

6.

(213) North RB, Cutchis PN, Epstein JA et al. Spinal cord compression complicating subarachnoid

infusion of morphine, case report and laboratory experience. Neurosurgery 1991; 29: 778-784.

(214) Patrick J. McIntyre, Timothy R. Deer, Salim M. Hayek. Complications of spinal infusion therapies.

Techniques in Regional Anesthesia and Pain Management 2007; 11: 183-192.

(215) Hassenbusch S, Burchiel K, Coffey RJ et al. Management of intrathecal catheter-tip inflammatory

masses, a consensus statement. Pain Medicine 2002; 3: 313-323.

(216) Murphy PM, Skouvaklis DE, Amadeo RJ et al. Intrathecal catheter granuloma associated with

isolated baclofen infusion. Anesthesia Analgesia 2006; 102: 848-852.

(217) Narouze SN, Mekhail NA. Intrathecal catheter granuloma with baclofen infusion. Anesthesia

Analgesia 2007; 104: 209-210.

(218) Thomsen C, Stahlberg F, Stubgard M et al. Fourier analysis of cerebrospinal fluid flow velocities,

MR imaging study. The Scandinavian flow group. Radiology 1990; 177: 659-665.

(219) Deer TR. A prospective analysis of intrathecal granuloma in chronic pain patients, a review of the

literature and report of a surveillance study. Pain Physician 2004; 7: 225-228.

(220) Hassenbusch S, Burchiel K, Coffey RJ et al. Management of intrathecal catheter-tip inflammatory

masses, a consensus statement. Pain Medicine 2002; 3: 313-323.

(221) Pasquier Y, Cahana A, Schnider A. Subdural catheter migration may lead to baclofen pump

dysfunction. Spinal Cord 2003; 41: 700-702.

(222) Ko WM, Ferrante FM. New onset lumbar radicular pain after implantation of an intrathecal drug

delivery system, imaging catheter migration. Regional Anesthesia and Pain Medicine 2006; 31: 363-367.

(223) Ford B, Pullman SL, Khandji A, et al. Spinal myoclonus induced by an intrathecal catheter. Moving

Disorders Journal 1997; 12: 1042-1045.

(224) Harney D, Victor R. Traumatic syrinx after implantation of an intrathecal catheter. Regional

Anesthesia and Pain Medicine 2004; 29: 606-609.

Summary

صــيـخلتلا

المرضى الذين ك, ةـالتخدير النصفي المستمر هو تكنيك له فوائد كثيرة في مواقف إكلينيكية معين

بأمراض ت حالتهم مصحوبة كانوا من كبار السن أو كان وسيخضعون لعمليات في الجزء السفلي من الجسم

)كإضطرابات صمامات القلب الشديدة(أو أمراض القلب ) كإنسداد الشعب المزمن(أخرى مثل أمراض الرئة

حيث أنهم سيستفيدون من تجنب تركيب أنبوبة حنجرية و مشاكل التخدير الكلي األخرى و في الوقت نفسه

مع االنواع األخرى من التخدير التي قد تحدث) كضغط الدم(تجنب التغيرات العنيفة في العالمات الحيوية

يمكن إستخدام هذا التكنيك بنجاح للتخدير النصفي إلجراء العملية و أيضاً لتخدير األلم بعد إجراء . النصفي

كما يمكن إستخدام القسطرة الشوكية لحقن األدوية على مدى فترات طويلة للسيطرة على . لعدة ساعات العملية

. تصلب العضالت األلم المزمن أو

أو ذات قطر ) micro-catheter<24G (القسطرة المستخدمة يمكن أن تكون ذات قطر صغير

إبرة شوكية ذات تفيد القسطرة ذات القطر الصغير في إمكان إستخدام . )macro-catheter>24G (كبير

و بالتالي تخفيض نسبة حدوث الصداع الذي يتبع إستخدام اإلبرة الشوكية و لكن مع مشاكل أيضاً قطر صغير

داخل اإلبرة على حسب نوع من-داخل القسطرة أو القسطرة-من-يمكن إستخدام تصميم األبرة-. تقنية اكثر

مدة في تقليل شدة و ) ®Spinocath(داخل القسطرة من-يساعد تصميم األبرة-. القسطرة المستخدمة

. الصداع الذي يتبع إستخدام األبرة الشوكية عن طريق تقليل تسرب السائل الشوكي من حول القسطرة

مراجعة الحاجة لهذا التكنيك مع كل : يوصى باالتيستخدام االمن للتخدير النصفي المستمر لتحقيق اإل

ستفاضة حول يجب مناقشة المريض بإ .مريض بذاته و التحقق من عدم وجود أي من التعارضات إلستخدامه

و أيضاً , متركيب القسطرة في ظروف كاملة التعقي. مميزات هذا التكنيك و أعراضه الجانبية و نسب حدوثها

يتم تركيب القسطرة بين . )كبيتادين التعقيم(يجب تجنب لمس طرف القسطرة للقفاز المعقم أو مادة التعقيم

يفضل تركيب القسطرة بجانب خط الوسط الظهري . ة أو الرابعة و الخامسةالفقرة القطنية الثالثة و الرابع

داخل الفراغ تحت ب الذي القسطرة جزء و يجب أن ال يتعدى طول ,خصوصاً في المرضى كبار السن

.سم 3-2العنكبوتي

عند وصف المريض حدوث أي ألم غير طبيعي أو تنميل باألطراف أثناء إدخال اإلبرة الشوكية أو

تمرير القسطرة من خاللها يجب سحب اإلبرة و القسطرة كوحدة واحدة و إعادة إدخالهما في نفس المستوى او

كما ,بطريقة واضحة" INTRATHECAL"يجب تعليم فتحة الحقن بالقسطرة بعالمة . في مستوى اخر

Summary

قاعدة إستخدام فضلبا دوكين الثقيل بالقسطرة حيث أن البوبيفاكين يتمتعالليدوكين أو اللي حقنيجب تفادي

متقدم و له خبرة حتي االن يوصى أن يقوم بتنفيذ هذا التكنيك طبيب تخدير . هذا الخصوصفي حجماً و اماناً

.في استخدام تقنيات التخدير النصفي المختلفة

الجديد في التخديرالنصفي تحت العنكبوتية المستمر

بحث مقدم لنيل درجة الماجستير في التخدير

مقدمه

اسالم أيمن محمد شوقي كحلة

تحت اشراف

ماهر فوزي محمود/ د.أ أستاذ التخدير

البشري كلية الطب

جامعة القاهرة

أحمد عبد العزيز عارف /د أستاذ مساعد التخدير

البشريكلية الطب


مها محمد اسماعيل/ د مدرس التخدير

كلية الطب البشري


كلية الطب البشري


2010

Updates in Continuous Spinal Anesthesia - Cairo...

Documents

Transcript of Updates in Continuous Spinal Anesthesia - Cairo...