Hemodynamic effects of vasopressor agents in hemorrhagic shock

Abstract

In experimental hemorrhagic shock there is a decline in blood flow to all organs and tissues of the body. Of the regions studied, there is initially less decline in flow to tissues supplied by the renal and superior mesenteric arteries and more to those supplied by the carotid and femoral arteries. Administration of metaraminol and norepinephrine may be effective in partially restoring blood flow, but with the degree of hypovolemia produced in these experiments, regional blood flow did not return to normal when blood pressure was raised to the control level. Metaraminol, in the experimental setting used, was more effective in partially restoring blood flow than norepinephrine. In human hemorrhagic shock, vasopressors should be used only as necessary in conjunction with replacement of blood volume and attempts to stop hemorrhage, and after careful consideration of their hemodynamic properties.