THORACIC AND ABDOMINAL NERVE BLOCKS

MODERATOR : Dr KAMAL KISHORESpeaker : Tapas Singh

Contents

• Paravertebral block• Intercoastal nerve block• Transversus abdominis plane block• Intrapleural block• Illioinguinal and illiohypogastric blocks• Thoracic epidural block• Celiac plexus block

PARAVERTABRAL BLOCKS

POSTOPERATIVE ANALGESIA:

• Thoracic surgery• Breast surgery• Cholecystectomy• Renal and ureteric

surgery• Herniorrhaphy• Appendectomy• Video-assisted

thoracoscopic surgery

SURGICAL ANESTHESIA:

• Breast surgery• Herniorrhaphy• Chest wound

exploration

MISCELLANEOUS

•Fractured ribs

•Therapeutic control of hyperhydrosis

•Liver capsule pain after blunt trauma

•Acute postherpetic neuralgia

Regional AnatomyWedge shaped area on both

sides of vertebra

BOUNDARIES:• Anterior/lateral: Parietal

pleura• Posterior: Superior costo-

transverse ligament• Medial: Postero-lateral

aspect of the vertebral body, intervertebral disc and the intervertebral foramen

COMMUNICATIONS:• Intercostal space laterally• Epidural space medially• Paravertebral space on

the other side via the prevertebral and epidural space.

Patient position & landmarksPosition : Sitting or lateral

decubitus, with kyphotic attitude supported by a attendant.

Landmarks :• Spinous processes

along the midline• Tip of scapula : T10• Paramedian line 2.5

cms lateral to midline

Technique• At thoracic level :

Spinous process of upper vertebrae is at level of transverse process of lower spine.

Needle Insertion Point: 2.5 cm lateral to the tip of spinous process.

Saggital section through the thoracic paravertebral space showing a needle that has been advanced above the transverse process.

Technique

Procedure consists of 3 maneuvers

1. Contacting transverse processes of individual vertebrae (depth 2-4 cms)

2. Withdrawing needle to skin level and reinserting it 10 deg caudal or cranial

3. Inserting needle 1 cm deeper than level of transverse processes

• Called “Walking Off” (Cranially/Caudally)

Technique

Technique (Continuous Thoracic paravertebral block)

• The same method can be modified and a catheter can be placed in the paravertebral space for giving more prolonged post operative analgesia

• A Touhy’s needle is used for the procedure and a catheter is inserted 5 cms beyond the tip of the needle

• Catheter is ideally inserted 1-2 segmental levels below the thoracotomy incision

Commonly used drugs

Onset(min)

Anesthesia (hrs)

Analgesia (hrs)

2% Lidocaine (plus HCO3 + epinephrine)

10-15 2-3 3-4

0.5% Bupivacaine (plus epinephrine)

15-25 4-6 12-18

0.5% ropivaicaine (+epinephrine)

12-25 4-6 12-18

Local Anesthetic: 3-4 ml/ level for multiple level block, 15-20 ml for single level, and infusion @ 0.1 ml/kg/h. Appropriate drugs: bupivacaine 0.25-0.5%, ropivacaine 0.25-0.5%, or lidocaine 1%; with epinephrine (2.5 μg/ml).

Mechanism and Spread of Anesthesia: 15 ml bupivacaine 0.5% in TPVs produces unilateral somatic block over 5 (range: 1-9) dermatomes, and sympathetic block over 8 (range 6-10) dermatomes.

Possible areas of spread:• May remain localized• May spread to contiguous levels above and below• Intercostal space laterally• Epidural space, mostly unilateral and insignificant, in up to 70%• Single 15-20 ml injection as effective as multiple 3-4 ml/site.• Increasing volume may predispose to bilateral anesthesia• If a wide block (≥ 5 dermatomes) is desired, preferable to do multiple

injections, or 2 injections several dermatomes apart

Contraindications

ABSOLUTE• Infection at the

site of needle insertion,

• Empyema• Allergy to local

anesthetic drugs, and

• Tumor occupying the TPVS.

RELATIVE• Coagulopathy • Kyphoscoliosis

(chest deformity may predispose to pleural or thecal puncture)

• Patient with previous thoracotomy: TPVs may be obliterated by scar tissue and adhesion of lung to chest wall

INTERCOASTAL NERVE BLOCKS(ICNB)

• Mostly used for postoperative analgesia after surgeries like thoracotomy, mastectomy, cholecystectomy, gastrostomy etc

• Neurolytic ICNB’s are used to treat chronic painful conditions like post thoracotomy and mastectomy pain

• Also used in rib fractures

Applied anatomy

• Each intercoastal nerve has four parts - gray ramus comminucans - posterior cutaneous branch - lateral cutaneous branch - anterior cutaneous branch

• Positioning – pt may be sitting, prone or lateral. key is to pull scapulae laterally to facilitate access to posterior angle of ribs above T7

• Inferior border of ribs marked just lateral to sacrospinalis muscle ( 6-8cm lateral to midline in lower ribs, 4-6cm in upper ribs )

• A 22-24 G inserted at 20 degree cephalad angle• After inserting to a depth of 1 cm rib is

encountered, which is walked off in cephalad direction

• Insert 3 mm more tilll a pop of internal intercoastal fascia is felt

• After negative aspiration, 3-5 ml of LA is injected

• 1-2% lignocaine with or without epinephrine, bupibacaine 0.25-0.5% and ropivacaine 0.5-0.75% is used

http://www.nysora.com/files/uploaded/regional_anesthesia/peripheral_nerve_blocks/nerve_stimulator_techniques/intercostal_nerve_block/5.jpg

• The ideal angle of entry into the subcostal groove is about 20° cephalad.

• A continuous catheter may be better tolerated in cases that require repeated blocks at multiple levels.

• ICNB provides excellent analgesia but is seldom adequate for intraoperative anesthesia.

• Supplemental analgesia may be required in continuous ICNB especially if the area of pain is wide.

• Epidural block should be considered as a better alternative to bilateral ICNBs because of the risk of bilateral pneumothorax and the potential for local anesthetic toxicity due the increased amount of local anesthetic required.

• Absorption of local anesthetic from the intercostal space is rapid and toxicity is usually an important concern.

• ICNB above T7 may be difficult because of the scapulae and an alternative technique such as paravertebral or epidural block should be considered.

complications

• Pneumothorax• Lung injury• Local anaesthetic toxicity• Peritoneal and abdominal viscera injury• Intrathecal drug injection

Transverse abdominis plane (TAP) block

• INDICATIONS appendectomyHernia repairCaesarean sectionAbdominal hysterectomyProstactectomyLaproscopic surgery

• Anterolateral abd wall supplied with ant. Rami of spinal nerves T7 to L1

•

27

Transversus abdominis plane block (TAP)

Mc Donnell et Al, An Analg 2007; vol 106 : 193-97.

28

Transversus abdominis plane block (TAP)

Mc Donnell et Al, An Analg 2008; vol 106 : 186-91.

• Triangle of petit • Double pop technique• First and second pop

external and internal oblique muscle respectively

• Dosage : 20 to 30 ml of any L.A in usual concentrations; volume dependent block

30

Transversus abdominis plane block (TAP)

complications

• Few,single case report of intra hepatic injection

• Intraperitoneal injection• Bowel hematoma• Transient femoral nerve palsy• Systemic toxicity

INTRAPLEURAL BLOCK

• Indications are open cholecystectomy, mutiple rib fractures and chronic painfull conditions like malignancy, acute herpes zoster and post herpetic neualgia

• Post thoracotomy analgesia is inconsistent due to presence of drain tubes and blood in pleural space

• Site is choosen between T6 to T8 at 10 cm from posterior midline

• Sponateously breathing patient, should be asked to hold his breath after exhalation

• In anaesthetised pt circuit should be disconnected• Can be performed in both lateral and supine position• L.A 20 to 25 ml,usually .25% bupivacaine is used• Continous infusions have also been employed at rate of

0.125 ml/kg/hr• Positioning of patient imp

complications

• Pnumothorax• Chest walll hematoma• Systemic absorption• Horner’s syndrome

Illioinguinal and illiohypogastric blocks

• Indications for ilioinguinal/iliohypogastric blocks include anesthesia for any somatic procedure involving the lower abdominal wall/inguinal region such as inguinal herniorrhaphy

• For analgesia after surgical procedures using a Pfannenstiel incision as for cesarean section and abdominal hysterectomy.

• Do not provide visceral anesthesia • When used for inguinal herniorrhaphy, the sac must be

infiltrated with local anesthetic to complete anesthesia for the procedure.

APPLIED ANATOMY

• Both the iliohypogastric and ilioinguinal nerves emanate from the first lumbar spinal root.

• Superomedial to the anterior superior iliac spine, the iliohypogastric and ilioinguinal nerves pierce the transversus abdominus to lie between it and the internal oblique muscles.

• Their ventral rami pierce the internal oblique to lie between the internal and external oblique muscles before giving off branches.

• The iliohypogastric nerve supplies the skin over the inguinal region. The ilioinguinal nerve runs anteroinferiorly to the superficial inguinal ring, where it emerges to supply the skin on the superomedial aspect of the thigh

• Initially, the anterior superior iliac spine is palpated and a mark made 2 cm medial and 2 cm superior from it .

• The needle is inserted through the skin puncture site perpendicular to the skin.

• Increased resistance is met as the needle encounters the external oblique muscle. A loss of resistance is appreciated as the needle passes through the muscle to lie between it and the internal oblique. After the initial loss of resistance and negative needle aspiration for blood, 2 mL of local anesthetic are injected.

• The needle is then inserted farther to encounter another resistance, which is the internal oblique muscle.

• A further loss of resistance is appreciated once the needle passes through the internal oblique to lie between it and the transversus abdominus muscle. After the second loss of resistance, another 2 mL of local anesthetic are administered.

• The needle is then withdrawn to skin and redirected at a 45-degree angle medially to again pierce the external and then the internal obliquemuscles . After each loss of resistance, 2 mL of local anesthetic are again administered.

• The needle is then returned to skin and inserted 45 degrees laterally, and the procedure is repeated. Thus, a total of 12 mL of local anesthetic is placed in a fan-like distribution between the external and internal oblique and the internal oblique and transversus abdominus muscles

Contraindications

• There are no specific contraindications for these blocks apart from the generic contraindications to performance of any regional block such as infection at the procedure site, allergy to local anesthetics, indeterminate neuropathy, and so on.

Thoracic epidural

• Most commonly used in thoracotomies for post op pain relief

• Anatomy of vertebral column makes technique of thoracic epidural slightly different

• Medain and para median approach

Celiac Plexus Block

• anesthesia for intra-abdominal surgery• reduce stress and endocrine responses to

surgery

Anatomy and Technique• contains visceral afferent and efferent fibers

derived from T5 to T12 by means of the greater, lesser, and least splanchnic nerves

• The vena cava lies anteriorly to the right, and on the left anteriorly is the aorta

• kidneys lie laterally, with the pancreas anterior

• patient in the prone position and a pillow beneath the abdomen

• lines are drawn connecting the spine of T12 with points 7 to 8 cm laterally at the lower edges of the 12th ribs

• A 20-gauge, 10- to 15-cm needle is inserted on the left side through a skin wheal at a 45-degree angle toward the body of T12 or L1

Side Effects and Complications

• Hypotension• Spinal, epidural, or intravascular injection• pneumothorax• puncture of viscera, such as the kidney,

ureter, or gut • retroperitoneal hematoma.

Thank you