Hematological and Pathological Studies of the Effects of Four-Hour Perfusion Level Heparinization on Dogs

DURING prolonged partial perfusion with extracorporeal circulation for cardiac support of patients with myocardial infarction and uncontrolled heart failure, progressively increasing hematuria was noted after the first hour.22 A part of the study to evaluate the etiology of tin's hematuria was to determine the effects of four-hour heparinization at perfusion levels on the various organs of dogs and on the coagulation mechanism Previous studies on humans have shown that heparin interferes with consumption of prothrombin, antihemophilic globulin,3, 12 factor V3, formation of Christmas factor,13 and in vitro inhibition of thromboplastin generation.1, 3, 12, 13 Prothrombin activity is known to decrease in the presence of heparin,12, 16 but platelet levels have been reported to be unchanged.14, 17 In dogs, heparin causes a profound but transitory drop in platelets.5, 17 None of the previous studies were carried out during and after prolonged periods of heparinization. The studies reported in this paper, arc specifically aimed at determining pathological organ changes and coagulation aberrations, if any, resulting from heparinization at a sufficient level and for a sufficient time to allow extra-corporeal support of the failing heart