Comparison of nitroprusside and nitroglycerine for controlling hypertension during coronary artery surgery.

The haemodynamic effects of infusing sodium nitroprusside or trinitroglycerine to control hypertension during operation were compared in 22 patients undergoing coronary artery surgery. Measurements were taken before induction of anaesthesia, during median sternotomy, and upon attainment of a stable decrease in arterial pressure. Both drugs significantly decreased arterial pressure without affecting heart rate or cardiac output. Systemic vascular resistance, pulmonary capillary wedge pressure and left and right ventricular stroke work were decreased also. Although nitroglycerine significantly decreased pulmonary vascular resistance, and produced a significantly greater decrease in central venous pressure than nitroprusside, these differences are unlikely to be important clinically.