The effect of prophylactic heparinization on DIC arising from transitory circulatory arrest in dogs

To evaluate the beneficial effect of heparin administration on the prevention of disseminated intravascular coagulation (DIC) which appears following circulatory arrest, experimental studies were carried out with one group of dogs during circulatory arrest (control group) and compared to a group of dogs that received heparinization (heparinized group) soon after termination of circulatory arrest. Dogs of the control group were subjected to transitory circulatory arrest with occlusion balloons in the aorta and the femoral vein for a period of 8 minutes and allowed to recover without further treatment. Dogs of the heparinized group were given continuous infusions of 20 units/kg/hour of heparin as soon as circulatory arrest was started. The control group developed DIC 5 hours after circulatory arrest; however, the heparinized group demonstrated reduced platelet counts and low levels of antithrombin III (AT-III) 2 to 3 hours subsequently to circulatory arrest, but these changes were not serious, and normal levels of platelet count and AT-III were restored rapidly thereafter. Prophylactic heparin therapy is, accordingly, recommended as a useful measure of preventing the occurrence of DIC in circulatory arrest and the subsequent detrimental consequences.