Comparison of halothane and enflurane anaesthesia for tonsillectomy in adults.

Halothane and enflurane in combination with N2O/O2 were compared in 103 adults undergoing tonsillectomy. Anaesthesia was induced with thiopental, and intubation was facilitated with suxamethonium. During halothane anaesthesia the mean heart rate ranged from 91 to 106 beats/min and the mean systolic arterial pressure from 111 to 127 mmHg. The values did not differ significantly from the corresponding values during enflurane anaesthesia. Electrocardiographic changes occurred in 56% and 31% of the patients anaesthetized with halothane or enflurane, respectively. the incidence of junctional rhythm, the most common ECG change, was 46% in the halothane group and 29% in the enflurane group. 19% of the patients in the halothane group and 31% in the enflurane group responded to surgical stimulus by swallowing or coughing. The responses were mostly short-lasting and did not much disturb the surgeon. The incidence of laryngospasm was 6% after halothane and 2% after enflurane anaesthesia. The mean total recovery score (0-10) was 6.1 after halothane and 6.3 after enflurane at arrival in the recovery room and 9.8 in both groups 30 min later. After halothane, nausea and vomiting occurred in 8 and 12% of the patients, respectively. The corresponding figures after enflurane were 2 and 8%. It is concluded that both halothane and enflurane are suitable anaesthetics for tonsillectomy in adults. The most striking difference between the anaesthetics was the significantly more common occurrence of ECG changes during halothane than enflurane anaesthesia.