Background: Cardiac arrest following regional anaesthesia for caesarean section though rare is the worst possible complication, especially so in a young parturient.
Case Report: A 30 year old gravida3para2 with no past medical history and two previous uneventful caesarean sections under regional anaesthesia had spinal anaesthesia for caesarean section following two failed CSE attempts and two failed SSS attempts with 0.5% hyperbaric bupivacaine 2.2 ml + fentanyl 15 mcg + morphine 100 mcg. Block height achieved at 5 min was C4. At 9 min, BP decreased from 125/80 preoperatively to 110/25 while HR stayed at 105/min associated with severe nausea followed soon by loss of consciousness and asystole. As there was no pulse or breathing, CPR was commenced immediately with 100% oxygen via bag mask. Intravenous (iv) atropine 0.6 mg was given with return of spontaneous circulation, sinus rhythm and consciousness after 15 seconds. At 24 min, BP was 110/28. At 28 min, surgery commenced. At 29 min, when BP decreased to 55/25 with HR 115/min, iv phenylephrine total 300 mcg, ephedrine total 15 mg and gelafundin 500 ml were given. At 34 min, BP was 80/35 and HR 125/min. At 35 min, baby was delivered with Apgar score 8/9. At 39 min, BP was 120/55, HR 125/min and SpO2 100%. At 48 min, umbilical cord arterial pH was 7.27. At 51 min, umbilical cord venous pH was 7.276. She had an uncomplicated course thereafter. 

Discussion: Successful resuscitation requires an understanding of the probable causes. The probable cause in this patient was a high neuraxial block with reduced venous return, possibly triggering a Bezold-Jarisch reflex with profound bradycardia and hypotension, and suppression of T1-4 cardiac-sympathetics. Thus, CPR together with iv atropine 0.6 mg was beneficial. Iv adrenaline 1 mg or iv vasopressin 40 U may also be used1. The high block could have been due to unintended epidural volume extension during the failed CSE attempts. Frequency of arrest for patients during spinal anaesthesia is about 2.9/10,000 and hospital survival for regional anaesthesia is about 65% (Kopp et al). 
References:
1.	Moitra VK, Einav S, Thies KC, et al. Cardiac arrest in the operating room: Resuscitation and management for the anaesthesiologist: Part 1. Anesth Analg 2017. 
Learning points: One should always have a ready individualised management plan for a successful outcome. 


09 / Unexpected cardiac arrest following spinal anaesthesia for elective caesarean section