Vascular resistance of dog foreleg during hemorrhagic shock

¹ Department of Physiology, Albany Medical College, Union University, Albany, New York

Anesthetized dogs were submitted to conventional bleeding and reinfusion procedures so as to be able to compare vascular pressure gradients in the forelimb during acute hemorrhage with those recorded subsequently during the development of normovolemic shock. In some animals venous outflow from the limb was recorded to permit calculation of vascular resistances. The results demonstrate a marked increase in arterial and small vessel resistance during shock as compared to the changes observed in acute hemorrhage. Venous resistance also was appreciably greater during shock than during acute hemorrhage, which would argue against the possibility that the hemodynamic failure in shock might relate to a generalized collapse of venomotor tone. The data also show a tendency toward elevation of large vein pressure in shock, interpreted as signifying some degree of cardiac failure.

Key Words: blood vessel resistance • hemorrhage • venous tone in shock

Submitted on October 8, 1964