Cardiac arrhythmias in children during outpatient general anaesthesia for dentistry: a prospective randomised trial

Background Deaths in children associated with outpatient general dental ana esthesia may be attributable to sudden cardiovascular collapse precipitated by Ventricular arrhythmias. A causal link between halothane anaesthesia, V entricular arrhythmias, and deaths has been suggested. We did a prospective , randomised trial to investigate the frequency and character of arrhythmia s during anaesthesia with halothane and the alternative anaesthetic agent, sevoflurane. Methods 150 children, aged 3-15 years, who needed dental extraction under g eneral anaesthesia were randomly assigned sevoflurane or halothane suppleme ntation of 66% nitrous oxide in oxygen with spontaneous ventilation. The ha lothane group (n=50) received halothane introduced in 0.75% increments, eve ry two to three breaths, to a maximum of 3.0%, with maintenance at 1.5%. Th e incremental sevoflurane group (n=50) received sevoflurane introduced in 2 % increments increased to a maximum of 8%, with maintenance at 4%. The 8% s evoflurane group (n=50) received sevoflurane introduced at 8%, with. mainte nance at 4%. Findings 24 (48%) children receiving halothane had arrhythmias compared wit h four (8%) receiving incremental sevoflurane (difference 40% [95% Ci for d ifferences 24-56] p<0.0001), and eight (16%) receiving 8% sevoflurane (diff erence 32% [15-50] p=0.0013). Halothane-associated arrhythmias occurred dur ing dental extraction or emergence and were mainly ventricular. Six (12%) c hildren in the halothane group had ventricular tachycardia. The methods of sevoflurane administration did not differ significantly for the frequency o f arrhythmias (p=0.357). Sevoflurane-associated arrhythmias were mainly sin gle supraventricular ectopic beats. Interpretation There was a strong association between halothane and ventric ular arrhythmias, especially ventricular tachycardia. The use of sevofluran e in preference to halothane could contribute to a decline in morbidity and mortality associated with dental anaesthesia.