Hemodynamics of intravenous nitroglycerin during aortic clamping
J. R. Zaidan, A. V. Guffin, G. Perdue, R. Smith and D. C. McNeill
Anesthetic management and dosage schedules of vasodilators have not been
standardized in many studies of aortic cross clamping (CCL). For this
reason, 25 consecutive patients with arteriosclerotic disease of the aorta
were studied, all having received the same anesthetic management. Six
patients who received nitroglycerin during the cross clamp period, at a
dosage of 0.25 micrograms/kg/min, were compared with 19 who underwent CCL
without the drug. Contractility was maintained in the nitroglycerin group,
but not in the other group. Despite a low cardiac index in both groups,
peripheral blood flow was adequate only in the nitroglycerin group.
Intrapulmonary shunt was higher in the nitroglycerin group, but it did not
significantly decrease the Pao2. Nitroglycerin infusion seems to be helpful
in maintaining pre-CCL contractility and adequacy of peripheral blood flow.