Cardiac arrhythmias during outpatient dental anaesthesia: a comparison of controlled ventilation with and without halothane.

The frequency and nature of cardiac arrhythmia during two controlled ventilation techniques for endotracheal anaesthesia in dental outpatients have been compared. Both techniques used nitrous oxide and oxygen with alcuronium, but in one the additional agent was halothane and in the other it was fentanyl. The frequency of arrhythmia in both groups was 5%. No ventricular arrhythmia was seen but benign nodal rhythm was noted. It is suggested that the anti-arrhythmia effect of non-depolarizing muscle relaxants may prevent ventricular arrhythmia in patients receiving halothane.