Acute Cardiovascular Effects of Ro5-4200: A New Anaesthetic Induction Agent *

Anaesthesia was induced in 12 patients by intravenous injection of R05-4200, a benzodiazepine. Consciousness was lost following injection of 2- 3 mg, given at a rate of 1 mg per minute. Respiratory minute volumes were well maintained, but arterial oxygen saturation fell significantly, by 1,5%. There was a 17 % increase in heart rate; a 26 % fall in mean arterial blood pressure; a 31 % fall in stroke volume and a 24 % drop in peripheral vascular resistance. Cardiac output was well maintained at control levels. The drug appeared to be compatible with ancillary drugs commonly used in anaesthetic practice. Post-operative recovery was uneventful. S. Afr. Med. J., 47, 382 (1973). R05-4200 is a tranquilliz « of the benzodiazepine group