Abstract
The effect of pancuronium on the cardiovascular system of the dog was studied in 12 greyhounds who were anaesthetized with pentobarbitone 30–40 mg/kg body weight. During the study, the animals were artificially ventilated to give an end-tidal carbon dioxide in the range 4·0–4·5 per cent. Duplicate cardiac output measurements were made before and ten minutes after the intravenous administration of pancuronium (0·18 mg/kg). There was a slight (but statistically insignificant) fall in cardiac output. Heart rate, aortic and pulmonary arterial pressures remained substantially unaltered. It is suggested that pancuronium should be used in the dog when muscle relaxation is required during pentobarbitone anaesthesia. In this way cardiovascular changes related to the drugs themselves will be minimized.