Effects of Constriction and Release of an Extremity

Abstract

The dangers of prolonged tourniquet application are as follows: 1. Interference with nutrition of the part sufficient to cause gangrene; 2. Paralysis, possibly due to prolonged pressure on the nerves; 3. Circulatory depression which frequently occurs after the release of a constrictor. Paolucci 1 and Fogliani 2 observed in animals that this circulatory depression was followed by death in many cases.

The present study is an attempt to evaluate the possible factors producing this fall of blood pressure and death. The factors considered were: 1. Return of blood to the limb (if this had been expressed before application of the tourniquet); 2. Reactive hyperemia (Bayliss); 3. Absorption of toxic metabolites; 4. Swelling of the limb by transudation.

Experiments were done on 19 dogs anesthetized with sodium barbital. One hind leg was constricted at the level of the hip joint for periods of from 2 to 20 hours. Six animals recovered after tourniquet applications of 2 to 6½ hours while 13 dogs died after constrictions of 3 to 20 hours. Seventeen percent of a control series of dogs died from the prolonged anesthesia.

In the animals dying, the hind quarters were symmetrically removed after the method of Blalock. 3 There was an average increase in weight of the ligated limb of 3.54% of the body weight. Plasma protein estimations showed the edema fluid to resemble diluted blood plasma. Johnson and Blalock 4 found that a loss of plasma equal to 2.4% of the body weight in 28 hours was sufficient to cause the death of dogs. In 3 cases gas was present in the tissues; Clostridia were found in a high percentage of cases from both the normal and the ligated leg. These were not tested for exotoxin production and their identity with B. welchi was therefore not definitely established (Trusler and Reeves 5 ).