PLATELET THROMBOXANE RELEASE AFTER SUBARACHNOID HEMORRHAGE AND SURGERY

We studied adenosine diphosphate-induced platelet aggregation and the associated release of thromboxane B2 in platelet-rich plasma from 88 patients with subarachnoid hemorrhage and 26 healthy controls. During the first 3 days after subarachnoid hemorrhage, the patients showed significantly decreased (p<0.05) platelet aggregability and thromboxane release relative to the controls, but these effects disappeared in a few days. Platelet count increased for 3 weeks after subarachnoid hemorrhage. Surgery in 67 patients was followed by significant increases in platelet aggregability (p<0.05) and thromboxane release (p<0.001). Greatest thromboxane release was found in the eight patients showing delayed (postoperative) ischemic deterioration with a permanent neurologic deficit Although platelet hyperaggregability and increased thromboxane release were particularly prominent in these eight patients, the role of these hematologic parameters in the pathogenesis of delayed ischemic deterioration remains unclear. © 1990 American Heart Association, Inc.