Intravenous Nitroglycerin Administration During Infrarenal Aortic Clamping
Survey of Anesthesiology
Twenty-five patients requiring infrarenal abdominal aortic clamping were studied during halothane, nitrous oxide anaesthesia. Aortic clamping caused reductions in cardiac htclex (CI), stroke volume index (SVI) and left ventricular stroke work index (LVSWI). Systemic vascular resistance (SVRJ increased. In seven patients CI was less than 1.8 l" rain -L m ~2. Intravenous administration of nitroglycerin, 1 # g. kg-t . min-J , for 20 minutes, accompanied by volume loading to maintain pulmonary
... tain pulmonary capillary wedge pressure, resulted in a sigtffficanl improvement in haemodynamic parameters. CI increased 24 per cent as a result of a 14 per cent it*crease in SVI and an eightper cent increase in heart rate. LVSWI increased 13 per cent and SVR decreased 21 per cent. The plasma nitroglycerin concentration at the time of these measurements was 2.9 +-1.0ng'ml -t. Aortic unclamping resuited in a mean maximum decrease of14 9 2 torr mean arterial pressure. Epinephrine. norepinephrine and plasma renin activity gradually increased during the period of the anaesthetic.