Vasodilator Therapy in Acute Hemorrhagic Shock

Abstract

Results of this study show that 18 of 20 dogs survived prolonged periods of arterial hypotension when phenoxybenzamine was given to maintain adequate flow to the vital tissues of the body. This drug was used in order to block the catecholamine-induced arteriolar vasoconstriction and the histamine-induced venospasm. Reduction of peripheral resistance results in an increased perfusion of the capillary beds and a correction of O 2 and CO 2 tensions at the tissue level. One must emphasize the need for adequate fluid replacement, with this form of therapy; otherwise the marked vasodilation which occurs with phenoxybenzamine might result in an inadequate circulation, even as the resistance to flow in hypoxic tissues is eliminated.