Bupivacaine

Cardiotoxicity A 22-year-old woman at 38.5 weeks of gestation was admitted for delivery. She complained of occasional dizziness, dyspnoea and palpitations with several syncopal attacks over the previous 2 ~cars. No abnormalities were detected on n~urological exammation although subsequent echocardiography revealed mitral valve prolapse. After 9 hours of unsuccessful labour a decision was made to perform a caesarean s{'clion. The fir~1 epidural catheter placed al L ,-4 aspirated blood so another was inserted at L4-5 successfully. Test doses ot .3'10 chloroprocaine did not give rise to any subarachnoid or systemic signs. but when a therapeutic dose of 20m I of 0.75% bupivacaine was injected the patient had a generalised seizure. She was immediately Intubatcd and resuscitated with oxygen. IV lignocame (hdocaine; 3 boluses of 100 mg. IOOmg and 50mg) and 2 doses of 44 mEq bicarbonate. A ventricular tachycardia of 200 beals/min lasting 26 min was noted. Subsequent cardioversion resulted in normal sinus rhythm. T/'c,(i.>cf (his case It/ustrates an example of hupll'acal f )(' CardlOl{).ncit.l'.' Although the te~t dose did not reveal intravascular placement of the catheter. cardiotoxicity may have resulted from the rapid passage of bupivacaine into the systemic circulation via an open epidural vessel aided by an elevated epidural pressure. resulting from injection of a large dose (20ml bupivacaine). Fractionating the dose (e.g. 5 ml/min) may reduce or eliminate this risk or an alternative anaesthetic technique should be considered if an epidural vessel is punctured. Furthermore. the use of succinylcholine (0 aid endotracheal intubalion ma>' have contributed to cardiotoxicity by increasing serum potassium. Conklin. K ~. and 7iatllnu·Rad. F.:'tncs[hes,ology 58: j~" IJun IQ8~)

0157-7271/83/0812·0003/0$01.00/0 'ADIS Press Reactions 12 Aug 1983 3