It is known that esmolol, a short-acting beta1-blocker, reduces anaesthetic requirement. In this study, we evaluated whether a low dose of landiolol, a new ultra-short-acting beta1-blocker, can reduce the sevoflurane requirement. Twenty-five patients undergoing hip surgery were randomly divided into two groups. Group A (n = 13) received landiolol (bolus injection of 0.031 mg.kg(-1) and continuous infusion at a rate of 0.01 mg.kg(-1).min(-1)). Group B (n = 12) received physiological saline. Landiolol and physiological saline were started before the induction of anaesthesia and continued until the end of anaesthesia. Anaesthesia was maintained with sevoflurane, 60% N(2)O and fentanyl. Sevoflurane concentration was controlled to keep the bispectral index at approximately 50. The end-tidal sevoflurane concentration and haemodynamics were measured during anaesthesia. The average end-tidal sevoflurane concentration in group A was significantly lower than that in group B (1.2 +/- 0.30 vs. 1.8 +/- 0.3%, P < 0.01). Maximum values of systolic arterial pressure showed no difference between the groups, whereas the maximum value of heart rate in group A was significantly less than that in group B (61 +/- 10 vs. 76 +/- 14 beats min(-1), P < 0.05). The results suggest that a low dose of landiolol significantly reduces the intraoperative sevoflurane requirement during sevoflurane/N(2)O/fentanyl anaesthesia in patients undergoing hip surgery.
