E.C.G. changes during halothane and enflurane anaesthesia for E.N.T. surgery in children

Abstract

E.c.g. changes were compared in 152 children undergoing adenoidectomy or adenotonsillectomy (T+A) under halothane or enflurane anaesthesia. Junctional rhythm occurred in 4-16% of the children in adenoidectomy groups and in 11-33% in T+A groups. Bundle branch block occurred in 4% of the children anaesthetized with halothane, but not with enflurane and was particularly common in association with thiopentone and T+A operations; one patient had bifocal ventricular tachycardia. QT interval was prolonged compared with control after thiopentone (P<0.001) and thiopentone and suxamethonium (P<0.02). QT interval was not changed after Althesin with or without suxamethonium. Mean preanaesthetic QT interval (±SEM) was significantly prolonged (492±22 ms; normal 440 ms) in children showing aberrant conduction with chaotic rhythm, but normal (438±5 ms) when bundle branch block or junctional rhythm was present during halothane anaesthesia. QT interval was prolonged significantly in enflurane but not in halothane anaesthesia. © 1981 Macmillan Publishers Ltd.