AN EXPERIMENTAL STUDY OF THE TOURNIQUET AS A METHOD FOR INDUCING CIRCULATORY FAILURE IN THE DOG

Abstract

A fatal circulatory shock was produced in over 90% of a large series of dogs by the release of a rubber tube tourniquet placed high upon each hip for a constriction period of 5 hrs. The survival periods following release of the constrictors ranged from 3-27 hrs., with the avg. at 5-6 hrs. A rapid and extensive rise in hematocrit, Hb and serum protein levels, and a fall in plasma vol. (T-1824) preceded the blood pressure decline, indicating that the initiating factor in the circulatory collapse was a massive local fluid loss into the injured legs. When this fluid loss was curtailed by means of tight bandages placed on the hind legs just prior to the release of the constrictors, all symptoms of shock were prevented. Any attempt to remove the bandages before 24 hrs. was followed by a rapid hemoconc, swelling of the legs, and death from circulatory failure in the usual time interval. If the bandages were allowed to remain in place for more than 24 hrs., they could be removed without fatal shock following. Saline infusions proved ineffectual in preventing death. Plasma transfusions given in a single inj; either before or after the appearance of shock could prevent death in but a small proportion of cases. If the same amt. of plasma was divided into 5 equal doses, given at the time of release of the constrictors, and at the end of the 1st, 2nd, 4th and 7th hrs., fatal shock was prevented. The positive effect of the intermittent transfusion could not be correlated with hemo-dilution changes.