Usefulness of checking platelet count before thrombolysis in acute ischemic stroke

Background and Purpose - Thrombolysis for acute ischemic stroke is strikingly time sensitive. Current guidelines require confirmation of a platelet count >= 100 000 before thrombolysis; however, obtaining this laboratory test may delay treatment. Methods - We queried our hospital database to identify patients with ICD-9 codes consistent with acute ischemic stroke from 2000 to 2005 and to determine platelet counts in these patients. Medical charts of patients with platelet counts <100 000 were reviewed to determine whether the patient had a known history of thrombocytopenia or conditions associated with thrombocytopenia. Results - A total of 1752 patients were identified, and 82 ( 4.7%) had a platelet count >= 100 000 at stroke onset. Only 6/1752 ( 0.3%) had a platelet count <100 000 which was not suspected based on initial history. All of these 6 patients had only mildly decreased platelet counts. Conclusions - An unsuspected platelet count <100 000 was found in 0.3% of patients at stroke presentation. In patients without a history of thrombocytopenia or predisposing factors, the benefit of earlier thrombolysis may outweigh the bleeding risk of inadvertently treating a patient with thrombocytopenia.