Haemodynamic studies during induction of anaesthesia for open-heart surgery using diazepam and ketamine.

In 14 patients undergoing open-heart operations the haemodynamic effects of diazepam 0.4 mgkg(-1) followed by ketamine 2 mg kg(-1) were studied. In eight patients undergoing coronary bypass surgery, the mean arterial pressure decreased significantly after diazepam from 90.3 +/-7.4 (SEM) to 78.0 +/-5.0 mm Hg (P less than 0.05). However, no changes occurred in six patients undergoing valve replacement. The subsequent administration of ketamine produced no significant changes in mean arterial pressure. No signfiicant change in heart rate occurred in any patient at any time during the period of study. No patient reported unpleasant emergence reactions after operation.