Effect of ketamine on ventricular dynamics of unanesthetized baboons

Ketamine hydrochloride is commonly employed to sedate or anesthetize laboratory primates but its cardiac actions have not been previously described in these animals. Four baboons, Papio cynocephalus, were chronically instrumented with electromagnetic flow detectors on the ascending aorta and common carotid artery. Cardiac output, peak aortic flow velocity and peak aortic flow acceleration are all depressed by Ketamine, 5 mg/kg i.m. Peak aortic flow acceleration and peak carotid flow acceleration were equally depressed. Thus, peak carotid flow acceleration is a useful indirect index of the left ventricular response to Ketamine in the baboon.