Usefulness of Checking Platelet Count Before Thrombolysis in Acute Ischemic Stroke

Abstract

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.

Scientific Rationale for the Inclusion and Exclusion Criteria for Intravenous Alteplase in Acute Ischemic Stroke

“…The risk of hemorrhagic complications is expected to be increased in the setting of severe thrombocytopenia, but the precise relationship between platelet count and bleeding risk is not well studied. Notably, because unsuspected thrombocytopenia is rare, 154 clinicians should not await the platelet count results before administering intravenous alteplase to patients with acute stroke unless there is a suspected bleeding abnormality, thrombocytopenia, or coagulopathy. 24 Whether a platelet count of 100 000 mm 3 is a justified threshold for withholding intravenous thrombolysis remains unclear.…”

Guidelines for the Early Management of Patients With Acute Ischemic Stroke

“…Retrospective reviews of patients who received intravenous fibrinolysis demonstrated very low rates of unsuspected coagulopathies and thrombocytopenia that would have constituted a contraindication to fibrinolysis. 130,131 The only laboratory result required in all patients before fibrinolytic therapy is initiated is a glucose determination; use of finger-stick measurement devices is acceptable.…”

Unsuspected Coagulopathy Rarely Prevents Iv Thrombolysis in Acute Ischemic Stroke

“…Laboratory testing, including determination of the platelet count, is frequently cited as a cause of treatment delay because it requires multiple steps-from veni- Table 1 Clinical characteristics of patients with acute ischemic stroke who presented to our emergency department within 3 hours of symptom onset or last seen well (n ‫؍‬ puncture to sample analysis and communication of results-each of which is fraught with potential for introducing unnecessary delays in the process. Given that no reliable data on absolute risk of administering IV tPA to patients with thrombocytopenia exist, 25 the authors suggest that the benefits of earlier thrombolysis outweigh the risks of bleeding complications when treating a patient with unsuspected thrombocytopenia. They also enforce the necessity of rapid laboratory testing that would, otherwise, allow thrombolytics to be discontinued promptly in those patients who subsequently were discovered to be thrombocytopenic.…”