The Effects of a Small dose of Scopolamine on the Heart Rate in the Halothane Anesthetized and Comstose Patient / 대한마취과학회지

ABSTRACT

It is well known that small dose of belladonna alkaloid(atropine, scopolarnine) has the effect of decreasing the heart rate in normal conscious subjects, but the mechanism involved in it remains still unanswered. Based on various lines of evidence, the most likely mechanism seems to be the blockade of sympathetic ganglion caused by the alkaloids and it is possible that the effect on the slower heart rate may differ in the depressed state of the sympathetic ganglion when under halothane anesthesia. The present study was undertaken, therefore, on comatose patients and halothane anesthetized patients with and without atropine premedication about 1 hour before anesthesia to observe the effect of a small dose of scopolamine(0.1 mg) which affects the heart rate more significantly than atropine in conscious subjects. The results were as follows 1) In the comatose patients, scopolamine(0.1 mg) produced a significant decrease in heart rate. 2) During halothane anesthesia without atropine premedication, scopolamine produced a slight decrease in heart rate. 3) During halothane anesthesia with atropine premedication, scopolamine produced a significant increase in the heart rate. These results indicate that scopolamine can further affect the sympathetic ganglion already depressed by halothane, and it is suggested that scopolamine is more effective in blocking the sympathetic ganglion than halothane.