Induction of anaesthesia with enflurane 5 vol% plus 70% nitrous oxide in oxygen was followed by suxamethonium 1, 1.5 or 2 mg kg-1 i.v. and the cardiovascular changes studied in 58 children. The eyelash reflex disappeared in 44 +/- 1.2 (SEM)s and the venepuncture could be performed 1.8 +/- 0.05 (SEM) min after the start of enflurane anaesthesia. The increase in systolic arterial pressure after tracheal intubation was less marked after enflurane than after thiopentone (taken from an earlier study). Heart rate increased significantly after all doses of suxamethonium, but no cardiac arrhythmias were seen. The QT interval was significantly prolonged by enflurane (P less than 0.001), but remained unchanged after suxamethonium.