Hemodynamic Responses to Dobutamine, Hydralazine and Sodium Nitroprusside Following Pentastarch Infusion during Cardiac Tamponade in Dogs

Abstract

Background : Cardiac tamponade results in a hemodynamic disorder associated with decreased cardiac output and blood pressure. To improve cardiac output in a subject with cardiac tamponade, cardiotonic drugs and vasodilators with blood volume expander can be used. The purpose of this study was to observe the hemodynamic effects of cardiotonic drugs and vasodilators following administration of plasma expander in the dogs with cardiac tamponade. Method : Three groups of dogs were studied during the induced cardiac tamponade. Following infusion of pentastarch, group I received dobutamine by dripping of 10ug/kg/min, followed by injection of 20ug/kg/min, group II received hydralazine (20 mg, 40 mg) and group III received sodium nitroprusside (5ug/kg/min, 10 g/kg/min). The heart rate, blood pressure, cardiac output and pulmonary arterial occluded pressure were measured. The atrial transmural pressure was calculated by subtracting intrapericardial pressure from mean atrial pressure. Results : Cardiac output was increased in the groups I and II, but mean arterial pressure was increased in only the group I. Atrial transmural pressure was not changed in all three groups. Conclusion : The most pronounced hemodynamic improvements during the cardiac tamponade is observed in group I with pentastarch-dobutamine combination. (Korean J Anesthesiol 1998; 35: 852∼860)