The influence of selected antiarrhythmic drugs on the hemodynamic parameters in rabbits during anesthesia. Part II. Thiopental anesthesia.

The aim of the study was to investigate the combined influence of thiopental and antiarrhythmic drugs: procainamide, N-acetylprocainamide, verapamil or propranolol on hemodynamic parameters in rabbits: arterial blood pressure, heart rate, cardiac output, stroke volume, peripheral vascular resistance, renal and hepatic blood flows. Propranolol used during thiopental anesthesia deepened the decrease of hepatic and renal blood flow resulting from the action of the anesthetic drug. Verapamil in a dose that did not change hepatic blood flow caused significant decrease of that parameter during thiopental anesthesia. Other hemodynamic changes observed after administration of antiarrhythmic drugs during thiopental anesthesia are essentially similar to those resulting from the action of antiarrhythmic drugs alone. The administration of procainamide or N-acetylprocainamide during thiopental anaesthesia in rabbits had no significant influence on hemodynamic changes evoked by thiopental alone. Verapamil injected to rabbits together with thiopental caused a significant decrease of blood flow in the liver, which was not observed after thiopental alone or verapamil alone. Propranolol injection together with thiopental caused a decrease of blood pressure, heart rate, cardiac output but an increase of vascular peripheral resistance, which was similar to the action of propranolol alone. Propranolol administered during thiopental anesthesia caused a significant decrease of the renal and hepatic blood flow, more marked than after the injection of that beta-blocker alone.