Tolerance of recently hemorrhaged rats to secondary trauma

¹ Surgical Section of the Research Institute, The Jewish Hospital of St. Louis and the Department of Surgery, Washington University School of Medicine, St. Louis, Missouri

The ability of rats to withstand a second hemorrhage 48 hours after the loss of one-half of the circulating volume was diminished from that of the normal control in terms of the absolute amounts which could be withdrawn. In terms of the relative amounts (ml whole blood withdrawn/100 ml total circulating blood volume) which could be withdrawn, the previously hemorrhaged rats showed a tolerance at least that of the controls. The red cell mass at this time was 67% of the control value. No difference in ability to tolerate bilateral hind leg tourniquet trauma was demonstrated between control and hemorrhaged animals at each of two different lengths of tourniquet application (3 1/2 and 4 hr.). Sleeping time determinations at two dose levels demonstrated no difference in tolerance to intraperitoneal sodium pentobarbital between normal and previously bled rats. It is postulated that decreased tolerance to trauma when occurring in association with diminished circulating volume is a function of the type of volume demand made by the trauma and the size of the specific volume compartment available.

Note:
With the Technical Assistance of Nelle Sicher