THE EFFECT OF HYPOTHERMIA ON THE INCIDENCE OF DELAYED TRAUMATIC INTRACEREBRAL HEMORRHAGE

HYPOTHERMIA HAS BEEN shown to cause coagulation abnormalities, primari ly related to platelet dysfunction. We reviewed coagulation function a nd the incidence of delayed traumatic intracerebral hemorrhage in a se ries of 36 patients with severe head injuries (Glasgow Coma Scale 3-7) enrolled in a prospective, randomized, clinical trial of therapeutic moderate hypothermia. Patients were randomized to a normothermic group (n = 16) or to a group cooled to 32 to 33 degrees C within 6 hours of injury (n = 20). Prothrombin times, partial thromboplastin times, and platelet counts were obtained in the emergency room and then again wi thin 24 hours of randomization. Delayed traumatic intracerebral hemorr hage occurred in 6 of 20 (30%) hypothermic patients and 5 of 16 (31%) normothermic patients. In the hypothermic group, 9 of 17 patients had an increased prothrombin time during hypothermic therapy, as opposed t o 11 of 16 in the normothermic group during the corresponding time per iod. The partial thromboplastin time was prolonged in 2 of 17 hypother mic patients and 2 of 16 normothermic patients. Three patients in the hypothermic group and one in the normothermic group developed thromboc ytopenia (a platelet count of less than 100,000). There were no signif icant differences between the two groups in the incidence of delayed t raumatic intracerebral hemorrhage, in measured coagulopathy, or in the mean values of measured coagulation parameters. Although the possibil ity of a hypothermia-induced coagulopathy has not yet been excluded, t he short-term use of hypothermia does not appear to increase the risk for intracranial hemorrhagic complications in head injuries.