Morbidity review

1. Morbidity review By NoorfarahnaduwahNurdin Supervisor Dr Tuan Norizan

2. 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

3. 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

6. 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

7. 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

8. Intraoperative • Uterus on/off atony • Resuscitated with • 1 pint gela • 1 pint sterofundin • 3 pints hartmann • Other meds • iv pitocin 10u • Imergometrine 0.5mg • Imhemabate 250 mcg • Iv morphine 3mg • Iv pitocin infusion 40u • EBL 1.4L

9. Post operative • Transferred to ICU for weaning • Hemodinamically not on inotropes • Extubated upon arrival to ICU

10. 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

11. Managing failed epidural analgesia for labour • Failed? • Partial block • Unilateral block • Patchy block • Inadequate block

12. 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

14. 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 • Ligamentumflavum ‘softer’ & less dense due to hormonal changes & edema • Difficulty blocking larger spinal nerve root e.g: sacral nerve root (17.53% failure rate)

15. Technique, methodology & equipment-related factors • 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

16. Technique, methodology & equipment-related factors • Catheter migration & malfunction • Up to 50% catheters migrate during labour. • Greatest change in position occur in BMI >30; change position from sitting to supine

17. Technique, methodology & equipment-related factors • 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

18. Technique, methodology & equipment-related factors • 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

19. Management of failed/inadequate epidural catheter in labour

20. Management of failed/inadequate epidural catheter in labour • Reassure patient • block inadequate, unilateral or if some dermatomes are spared? • Withdraw catheter until 2-3cm left in space then give another dose of analgesic • Change patient position when administrating the epidural. eg: • Supine position for unilateral block • Sitting up position for sacral block *results of effectiveness mixed

21. Management of failed/inadequate epidural catheter in labour • 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) • Add opiates & other adjuvants • Boluses epidural fentanyl 25-50mcg • Others, boluses clonidine 150mcg

22. Management of failed/inadequate epidural catheter in labour • If failed to get sensory block after 30 minutes, consider: • Resite epidural catheter

23. Management of failed/inadequate epidural catheter in labour • 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.

24. Management of failed/inadequate epidural catheter in labour • 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

25. Management of failed/inadequate epidural catheter in labour • 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

26. Management of failed/inadequate epidural catheter in labour • If insufficient time to resite epidural, • supplementary systemic analgesic e.g. • small doses fentanyl/remifentanil every 1-2 mins; • entonox, • local (perineal anaesthesia)

27. Extending epidural analgesia for caesarean section

28. 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

29. 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 intraoperativeconvertion to GA

30. 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

31. 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 & adjuvantsproduces faster onset anaesthesia

32. Local anaesthesia • Lidocaine 2% • Recent study showed that alkalanized 2% lidocaine mixed with epinephrine 1:200,000 reduced onset time of anaesthesia & produced better quality anaesthesia • Ropivacaine 0.75%-1%, levobupivacaine 0.5% • Less likely produce cardiac complications compared to bupivacaine

33. Adjuvants • 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

34. Adjuvants • 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 • Opioids • Improve quality of anaesthesia

35. Inadequate regional anaesthesia for caesarean section

36. 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

37. Prevention • Preexisting epidural analgesia • Choice of regional anaesthesia technique • Use of opioids • Testing of block • Time consideration • Miscellaneous consideration

38. 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.

39. 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

40. 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

41. Use of opioids • Fentanyl + intrathecalbupivacaine • faster onset • improve perioperative anaesthesia without increase in side effects if moderate doses are used • Intrathecal morphine/diamorphine prolonged postoperative analgesia

42. 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

43. 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.

44. 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

45. Management of inadequate regional anaesthesia for caesarean section

46. 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

47. 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

48. Before surgery • Problems with epidural anaesthesia • A failed block • A unilateral or patchy block • A block height remains persistently below required T4 level

49. 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

50. Before surgery • Its crucial to identify non-functional epidural block perioperativelybefore 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