The effect of halothane with nitrous oxide on baroreflex control of heart rate in man.

The assess the effect of halothane with 70 per cent nitrous oxide on the human baroreflex, we observed the heart rate response to pharmacological elevation of blood pressure in subjects anaesthetized to the 1 MAC and 1.25 MAC levels. We observed, in comparison to the awake control, that at 1 MAC halothane with 70 per cent nitrous oxide and oxygen, the baroreflex was depressed and this became more significant at 1.25 MAC anaesthesia. In comparison to previous similar studies on the effect of halothane-oxygen anaesthesia, there was significantly less baroreflex depression at equianaesthetic doses with halothane with 70 per cent nitrous oxide.