Dose-response to anaesthetic induction with sufentanil: haemodynamic and electroencephalographic effects.

<bold>Purpose: </bold>To determine the effect of a five-fold variation in sufentanil dose on the haemodynamic and electroencephalo graphic (EEG) response to anaesthetic induction and tracheal intubation.<bold>Methods: </bold>Thirty-four patients undergoing elective coronary artery bypass grafting (CABG) participated in this randomized double-blind study. Patients in Group L (n = 17) received 3 micrograms.kg-1 sufentanil and those in Group H (n = 17) 15 micrograms.kg-1. Premedication was 60 micrograms.kg-1 lorazepam po. Anaesthesia and neuromuscular blockade were induced by infusing sufentanil and 0.15 mg.kg-1 vecuronium i.v. over five minutes. Haemodynamic data and the electroencephalographic (EEG) spectral edge were acquired by computer and compared at Control, Induction and Intubation.<bold>Results: </bold>Sufentanil dose did not affect the haemodynamic or EEG response at end-induction. No bradyarrhythmias occurred, and the incidence of hypotension was 12% in both groups. However, during induction apparent electromyographic artifacts and a transiently greater increase in heart rate were observed in Group H. The serum sufentanil concentration at Induction was 6.1 +/- 1.8 ng.ml-1 in Group L and 25.4 +/- 8.8 ng.ml-1 in Group H, and did not correlate with haemodynamic changes. No patient recalled any intraoperative event.<bold>Conclusion: </bold>Increasing sufentanil dose from 3 to 15 micrograms-1 does not influence the ultimate haemodynamic response to induction. Combined with lorazepam premedication, 3 micrograms-1 sufentanil produces near-maximal haemodynamic and EEG effects and is adequate for induction and tracheal intubation of patients undergoing CABG. Sufentanil 15 micrograms.kg-1 is no more efficacious, and causes transient cardiovascular stimulation. [ABSTRACT FROM AUTHOR]