Protection by fentanyl against cardiac dysrhythmias during induction of anaesthesia

The effect of fentanyl on electrocardiographic changes during anaesthetic induction was studied in 113 adults and 77 children. The adults were pretreated with fentanyl 1, 2 or 3 micrograms kg-1 and the children received fentanyl 1 or 2 micrograms kg-1 as pretreatment. The control groups received no pretreatment. Two minutes after the pretreatment, thiopentone 5 mg kg-1 was injected followed by succinylcholine 1.5 mg kg-1 before laryngoscopy and intubation. In control adults, ventricular ectopic beats (VEB) occurred in 26% of the patients whereas fentanyl in all doses totally prevented them. In children, the incidence of VEB was 22% in the control group whereas both doses of fentanyl prevented the occurrence of VEB. In any doses, fentanyl did not prevent the prolongation of QT interval after succinylcholine.