[Chronic subdural hematoma: study of 161 patients and the relationship with coagulation abnormalities].

The chronic subdural hematoma represents one of the most frequent types of intracranial hemorrhage. One hundred sixty one patients operated in the Clinical Hospital of State University of Campinas-SP (UNICAMP) from April 1994 to May 2000, were analyzed retrospectively in order to characterize the population and to study the importance of the pre-operative coagulation analysis in the outcome. The majority of the population was male (86%), white (85.1%) and in the fifth decade (median age: 57 years). A high mortality index in the postoperative period was found in patients with INR (international normalized ratio) values greater than 1.25 and/or thrombocytopenia (p<0.001 and p=0.004 respectively). Patients with previous head injury history (76%) showed a lower mortality (p=0.044). The results stand out the importance of the pre-operative evaluation with coagulation studies in order to correct possible abnormalities.