[Effect of diazepam on cardio-vascular and psychotomimetic action of ketamine administered as continuous intravenous drip. Double-blind study (author's transl)].

Abstract

Sixty-four women undergoing non-abdominal operations were anaesthetized with ketamine administered as a continuous intravenous drip combined or not with diazepam. This double-blind, randomised study assessed the effects of diazepam on the dosage, the cardio-vascular stimulation, and the psychotomimetic side-effects of ketamine. At the induction, ketamine was given in a dose of 2 mg/kg in combination with diazepam 10 mg or placebo i.v. followed by a continuous infusion of ketamine at variable rate. The amounts of ketamine necessary for anaesthesia was significantly reduced by diazepam, from 4.51 mg/kg to 3.55 mg/kg (p less than 0.001). The sympathomimetic effect of ketamine was significantly decreased by diazepam, as the increase in pulse rate as well as in blood pressure was less important (p less than 0.05). The frequency of hallucinations dropped from 30.0 p. cent to 2.9 p. cent with diazepam, while the total frequency of psychotomimetic side-effects fell from 36.6 p. cent to 11.8 p. cent (p less than 0.05). Although the frequency of psychotomimetic side-effects is still high with this method, it may be recommended to use a continuous drip of ketamine administration for anaesthesia of hypovolaemic and other poor risk patients.