Cardiac Arrhythmias in Intubated Children During Adenoidectomy. A Comparison Between Enflurane and Halothane Anaesthesia

In 75 children undergoing adenoidectomy, occurrence of cardiac arrhythmias and influence of anaesthesia on respiration were studied during halothane and enflurane anaesthesia. All the children were intubated orally. In 25 children halothane, and in another 25 children enflurane was used during spontaneous ventilation. Twenty-five children were also followed during halothane anaesthesia with manually controlled ventilation. The overall incidence of cardiac arrhythmias was higher during halothane anaesthesia (72% at spontaneous breathing and 68% with controlled ventilation) than during enflurane anaesthesia (32%, P less than 0.05). Ventricular arrhythmias were noted in 20% of the spontaneously breathing children in 12% of those with controlled ventilation during halothane anaesthesia. Three children breathing spontaneously during halothane anaesthesia developed ventricular tachycardia. During enflurane anaesthesia the incidence of ventricular arrhythmias was lower (8%) in spite of higher end-tidal CO2 tensions and an anaesthetic depth that was only just the level needed to allow intubation. The incidence of ventricular arrhythmia during halothane anaesthesia was shown to be influenced by the anaesthetic technique used, which was not found with enflurane anaesthesia. The greater stability in cardiac rhythm with enflurane indicates a more favourable effect of this agent on the myocardium as well as a decreased sympathetic response to anaesthesia and surgery as compared with halothane anaesthesia.