Morbidity review
By Noorfarahnaduwah Nurdin
Supervisor Dr Tuan Norizan
•Madam F, G2 P0+1•No known medical illness•Height 151cm, weight 80kg, BMI 35.09
•Admitted to labour room at 9pm▫Os 3cm, contraction 2:10
•Was referred for epidural anaesthesia
Upon review @ 1am•Patient was on entonox•Bp 130/68 mmhg, pr 90/min•Epidural inserted at level L3L4•Anchored at 10cm•Skin to space 5cm•Test dose 3mls lignocaine 2%•Loading dose 8 mls 0.2% ropi + 50mcg
fentanyl•Started on infusion ropi 0.1% + 2mcg/ml
fentanyl 6mls/hr
5.00 am
Pain score 7-8/10 Increase infusion 13 mls/hr
3.00 amPain score 7-8/10
Increase infusion 10 mls/hr + bolus 3 mls
lignocaine 2%
1.30 am
Pain score 7-8/10 Increase infusion 8 mls/hr
10.45 am
Posted for EMLSCS for fetal distress
10.30 amPain score 7-8/10 Bolus 3 mls ropi 0.2% +
cont infusion 13 ms/hr
7.30 am
Pain score 7-8/10 Bolus 3 mls ropi 0.2% + cont infusion 13 ms/hr
In OT•Epidural was removed •Spinal anaesthesia was given at level L3L4▫Heavy marcaine 0.5% + morphine 0.1mg
+ fentanyl 20mcg (total volume 2.2mls)
•About 4 minutes after spinal, complaint of perioral & upper limbs numbness
•Bp dropped down to 70/40mmhg -> responded with phenylephrine
In OT•Spo2 dropped to 88-90%•Also complaint of difficulty in breathing•GCS 15/15•Converted to GA•Intubated with RSI technique
▫STP 250mg▫Scoline 100mg▫CL 1
•bp prior to intubation 120/57mmhg, pr 118/min
Intraoperative•Uterus on/off atony•Resuscitated with
▫1 pint gela▫1 pint sterofundin▫3 pints hartmann
•Other meds▫iv pitocin 10u▫Im ergometrine 0.5mg▫Im hemabate 250 mcg▫Iv morphine 3mg▫Iv pitocin infusion 40u
•EBL 1.4L
Post operative •Transferred to ICU for weaning•Hemodinamically not on inotropes•Extubated upon arrival to ICU
Issues •Inadequate epidural in labour as pain relief
•How to manage patient with epidural proceed with emergency c-sec▫Choices of drugs & doses
•Non functioning epidural in patient proceed with emergency c-sec▫Role of spinal, CSE & GA
Managing failed epidural analgesia for labour
•Failed?▫Partial block▫Unilateral block ▫Patchy block▫Inadequate block
Principle of management•Understand causes & factors predictive of
failed epidural
•Understand why functioning epidural catheter for labour becomes non-functional for c-sec
•Enumerate approaches to manage failed epidural for labour analgesia & operative delivery
•Recognize possible consequences of spinal anaesthesia following failed epidural block
Causes of failed
analgesia
Anatomical factors
Technique, methodology & equipment-
related factors
Initial catheter
misplacement
Catheter migration & malfunction
Catheter malfunction
& defect Patient-
related & other risk
factorsTechnical
skills/performance factors
Anatomical factors•Presence of midline epidural band/connective
tissue -> difficult to thread epidural catheter through Touhy needle -> coiling catheter during introduction
•> lumbar lordosis -> decrease intervertebral space
•Ligamentum flavum ‘softer’ & less dense due to hormonal changes & edema
•Difficulty blocking larger spinal nerve root e.g: sacral nerve root (17.53% failure rate)
Technique, methodology & equipment-related factors
1. Initial catheter misplacement ▫ Accidental transforaminal passage▫ Migration of catheter into anterior
epidural space▫ Unintended placement of catheter in
paravertebral space
*increased distance from skin to space correlates to higher incidence of unilateral block
Technique, methodology & equipment-related factors
2. Catheter migration & malfunction
▫ Up to 50% catheters migrate during labour.
▫ Greatest change in position occur in
BMI >30; change position from sitting to supine
Technique, methodology & equipment-related factors
3. Catheter malfunction & defects▫ Catheter knotting/kinking, blocked catheter
‘eyes’▫ Blocked terminal eye -> higher incidence of
unsatisfactory blocks (32%) compared to lateral eyes blocked
▫ Loss of resistance to air method -> higher incidence of inadequate analgesia compared to saline method
▫ Optimal length catheter left in space 2-6cm
Technique, methodology & equipment-related factors
4. Patient-related & other risk factors▫ Morbidly obese; BMI >30 higher risk failed
block & inadequate analgesia
▫ Presence of radicular pain during needle/catheter insertion
▫ Occipital posterior presentation of fetal head
▫ Inadequate analgesia from initial dose
▫ Labour duration >6 hours
Management of failed/inadequate epidural catheter in labour
Management of failed/inadequate epidural catheter in labour
• Reassure patient
• block inadequate, unilateral or if some dermatomes are spared?
1. Withdraw catheter until 2-3cm left in space then give another dose of analgesic
2. Change patient position when administrating the epidural. eg:
Supine position for unilateral block Sitting up position for sacral block*results of effectiveness mixed
Management of failed/inadequate epidural catheter in labour
3. Changing loading dose Bigger volume of bolus dose of dilute
epidural analgesic (eg 0.125% ropi/less) shown to be >effective than smaller volume but >concentrated dose (eg 0.2% ropi)
4. Add opiates & other adjuvants Boluses epidural fentanyl 25-50mcg Others, boluses clonidine 150mcg
Management of failed/inadequate epidural catheter in labour
•If failed to get sensory block after 30 minutes, consider:
1. Resite epidural catheter
Management of failed/inadequate epidural catheter in labour
2. Perform CSE▫ Risk high block if spinal dose is too large &
extend of block may be unpredictable
▫ If desired dermatome level not reached after spinal, upper sensory level may be increased by injecting 5mls saline epidurally ( epidural volume extension (EVE))
▫ Upper sensory block tends to be several dermatomes higher after CSE than in plain epidural top-ups, especially if done after induction of analgesia.
Management of failed/inadequate epidural catheter in labour
3. Perform single shot spinal• May be considered if delivery is imminent & risk
for c-sec is minimal
• Use of hyperbaric LA solution given in sitting position very effective
• Progression of block should be monitored closely
• Epidural top-ups should not be administered during the last 30 minutes(if time permits)
• May need to reduce dose by 20-30% than usual
Management of failed/inadequate epidural catheter in labour
4. Supplemental caudal anaesthesia
• Performed when the unblocked segments are sacral
• Should be done by experienced practitioner with carefully calibrated doses
• Generally not recommended due to high risk of local toxicity & accidental injected to foetus
Management of failed/inadequate epidural catheter in labour
5. If insufficient time to resite epidural, • supplementary systemic analgesic e.g. • small doses fentanyl/remifentanil every
1-2 mins;• entonox,• local (perineal anaesthesia)
Extending epidural analgesia for caesarean
section
Principles of management•Patient should be transferred quickly to OT for top ups where monitoring & resuscitation equipment available▫Potential adverse effect -> excessive high
block requiring intubation & accidental intravascular injection may result in seizures & cardiac event
•Performing test dose before epidural top ups may avoid potential complications, but may cause delay
Principles of management•Regular follow up patient receiving epidural anaesthesia in labour
▫Identify patients with suboptimal block -> may have inadequate intraoperative anaesthesia after top-up lead to intraoperative convertion to GA
Principles of management▫If c-sec is required, consider removing epidural catheter & convert to spinal/CSE
Reduce risk of inadequate anaesthesia & ad hoc conversion to GA.
*Risk of excessively high block, may considered lower dose of intrathecal drugs
Agents used to extend epidural blockade for caesarean section
•Usually 15-20mls of local anaesthesia needed to produce adequate block for c-sec
•Using combination of drugs & adjuvants produces faster onset anaesthesia
Local anaesthesiaI. Lidocaine 2%
▫ Recent study showed that alkalanized 2% lidocaine mixed with epinephrine 1:200,000 reduced onset time of anaesthesia & produced better quality anaesthesia
II. Ropivacaine 0.75%-1%, levobupivacaine 0.5%
▫ Less likely produce cardiac complications compared to bupivacaine
Adjuvants I. Epinephrine
▫ Reduces toxicity risk by decreasing systemic absorption of local anaesthetics from extradural space
▫ Confer some additional analgesic property
▫ Cause tachycardia if injected intravascular, hence warn the intravascular migration of epidural catheter
Adjuvants II. Sodium bicarbonate
▫ May increases speed of onset of surgical anaesthesia by increasing pH -> increase proportion of non-ionized lipid soluble LA that can diffuse into the axon
III.Opioids ▫ Improve quality of anaesthesia
Inadequate regional anaesthesia for caesarean section
•Regional anaesthesia recommended for caesarean section
▫Provide effective postoperative analgesia via intrathecal/epidural opioids
▫Avoiding GA hazards eg difficult/failed airway, aspiration of gastric contents
Prevention a. Preexisting epidural analgesia
b. Choice of regional anaesthesia technique
c. Use of opioids
d. Testing of block
e. Time consideration
f. Miscellaneous consideration
Pre-existing epidural analgesia
•Functioning epidural allows sufficient time to top up for pain free emergency c-sec
•Epidural catheter should be checked to ensure that its functioning well.
Pre-existing epidural analgesia•If amount of LA to maintain analgesia
during labour significantly higher than usual
▫may due to non functioning epidural catheter & may need to be replaced
•Regular review & identifying high risk parturient early can help reduce incidence of emergency surgery that needed GA
Choice of regional anaesthesia technique
•Single shot spinal anaesthesia ▫ not extendible in event of inadequate
anaesthesia
•If surgery expected to be longer & difficult than usual -> CSE may be a better option
Use of opioids•Fentanyl + intrathecal bupivacaine
faster onset improve perioperative anaesthesia without increase in side effects if moderate doses are used
•Intrathecal morphine/diamorphine prolonged postoperative analgesia
Testing of block•Usual ways
▫Loss sensation to touch/pressure,▫Cold temperature &▫Pin prick
•Light touch > reliable predictor for adequate SA
•Loss of pinprick sensation to T4 acceptable in epidural anaesthesia▫Bilateral LL weakness -> indicator top ups
in epidural taking effect
Time consideration•Time should be given for surgical anaesthesia to develop, particularly for epidural block▫May not be feasible in extremely emergent
situation eg cord prolapse/severe foetal distress
•Patients with epidural catheter in situ for labour analgesia, additional bolus doses may be administered once the decision for caesarean delivery made.
Miscellaneous consideration•Presence of patient’s partner in OT may be reassuring & have calming effect on patient
•Sympathetic approach by anaesthesiologist + gentle approach at surgical dissection & manipulation by surgeon can help ensure patient comfort
Management of inadequate regional anaesthesia for caesarean section
•Management option depends on▫The indication & urgency of caesarean
section
▫The time of diagnosis of inadequate regional block
▫Pre-existing regional blockade (if any)
▫The nature & severity of the pain experienced
•Risk of GA & regional anaesthesia must be considered for patients▫morbidly obese
▫exhibit features of potential difficult airway
▫have active respiratory tract infection
*in such situation, GA must be undertaken with extreme caution
Before surgery•Problems with epidural anaesthesia
▫A failed block
▫A unilateral or patchy block
▫A block height remains persistently below required T4 level
Before surgery•Measures that can be done to improve block▫Provide additional doses of LA
with/without opioids
▫Adjusting epidural catheter
▫Positioning the patient on unblocked side before top-ups
Before surgery
•Its crucial to identify non-functional epidural block perioperatively before administering maximum volume of local anaesthetic
•If there’s no time constraint & no technical difficulty in administering the first epidural block -> possible to replace epidural catheter. ▫Risk of excessive local anaesthetic
Before surgery•Use of spinal anaesthesia following failed epidural block -> highly controversial.
*may cause high block requiring tracheal intubation, ventilation & cardiovascular resuscitation.
•However, it still can be an option if appropriate precautions & technique modifications are taken such as▫Avoiding epidural boluses immediately
before spinal injection
▫Using a lower spinal dose
▫Intentionally delaying the placement of patient in a supine position following spinal injection of hyperbaric of LA in sitting position
Before surgery
Before surgery •Failed spinal block can occur despite
presence of CSF backflow due to anatomical anomalies or drug failure
•Management include ▫CSE placement at different lumbar
interspaces▫If needed, proceed to GA
During surgery before delivery of foetus•Some patients may be anxious about being
fully awake during procedure -> often requiring reassurance
•If an epidural catheter is present▫Additional top ups 3-5 mls of LA (eg 2%
lidocaine with 1:200,000 adrenaline & NaHCO3) may be given together with 50mcg fentanyl
During surgery before delivery of foetus
•Other options include ▫Entonox▫small iv doses of ketamine or▫ short acting opioids (eg alfentanil)
•Conversion to GA should be strongly considered in patients whose pain persist despite of the above interventions
During surgery after delivery of foetus•Management option include
▫the previous measures▫use of iv longer acting opioids (eg meperidine,
morphine)
•Patient must not be over sedated to maintain airway & protect against gastric aspiration
*explain to patient post delivery to explain regarding failed blocks & management option available if she presents again in future.
Conclusions •Using combination of drugs & adjuvants
produce faster onset but may delay time•Mixing several drugs together may lead to
drug errors•Epidural has multiple benefit but has up to
14-20% failure rate•In situation where epidural anaesthesia not
functioning in patient posted for EMLSCS, decisions regarding other modalities need to be discussed with specialist
•Documentation
Reference
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