Haemodynamic stability with midazolam-ketamine-sufentanil analgesia in cardiac surgical patients.

Although sufentanil in high doses may result in deep coma sufficient to conduct coronary-bypass surgery painlessly in patients, its side effects, e.g., bradycardia and hypotension, may lead to complications in some patients. Since ketamine causes central sympathetic stimulation, we attempted to counteract the vagomimetic effects of sufentanil by ketamine. Anaesthesia was induced in patients, (n = 15), for elective coronary artery-bypass surgery with 0.12 mg.kg-1 midazolam IV, followed by 1 mg.kg-1 ketamine and 0.6 micrograms.kg-1 sufentanil IV eight minutes later. Subsequently, pancuronium 0.1 mg.kg-1 was given to facilitate tracheal intubation. Three minutes later, the trachea was intubated, and ketamine 1 mg.kg-1.hr-1 IV infusion was started. Incremental doses of 0.6 micrograms.kg-1 sufentanil were given whenever a greater than 15 per cent increase in rate-pressure product was observed. The mean +/- S.E.M. dose of sufentanil before cardiopulmonary bypass was 6.5 +/- 0.6 micrograms.kg and 9.1 +/- 0.9 micrograms.kg for the entire procedure. Although midazolam alone caused reductions in systolic BP, SVR and LVSWI, other haemodynamic variables were not altered. The administration of this anaesthetic technique caused no clinically important adverse haemodynamic changes and/or ST-segment changes and prevented the adverse haemodynamic changes caused by intubation, skin incision, sternotomy and periaortic dissection. Adequate analgesia, complete amnesia and early recovery of wakefulness were observed.