Calc Function

    • Calcs that help predict probability of a diseaseDiagnosis
    • Subcategory of 'Diagnosis' designed to be very sensitiveRule Out
    • Disease is diagnosed: prognosticate to guide treatmentPrognosis
    • Numerical inputs and outputsFormula
    • Med treatment and moreTreatment
    • Suggested protocolsAlgorithm





    Chief Complaint


    Organ System


    Patent Pending

    HAT (Hemorrhage After Thrombolysis) Score for Predicting Post-tPA Hemorrhage

    Assesses hemorrhage risk after tPA.
    When to Use
    Why Use
    • The HAT Score can help determine risk/benefit of tPA in borderline cases for emergency and neurology providers.
    • It can also help determine which patients need the closest monitoring if given tPA.

    While symptomatic ICH definitions vary greatly, it is clear from several studies that increasing HAT Score correlates with increasing risk of symptomatic ICH and fatal ICH, from <5% at low scores to >10% at highest scores.

    The HAT Score can objectify tPA risk which is often difficult with gestalt alone, and provide patients and family members information about possible risk and benefit.


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    Next Steps
    Creator Insights


    • Stop tPA immediately if it is still running.
    • All patients with ICH should receive neurosurgical consultation.
    • Consider hematology consult to reverse the tPA.
    Dr. Magdy Selim

    About the Creator

    Magdy Selim, MD, PhD, is chief of the Division of Stroke and Cerebrovascular Diseases at Beth Israel Deaconess Medical Center. He is also a professor of neurology at Harvard Medical School. His current research interests include cerebrovascular disease, brain imaging, and thrombolysis. His field of interest is advancing the diagnosis and improving the treatment of stroke, with a specific focus on developing new therapies for patients with a brain hemorrhage.

    To view Dr. Magdy Selim's publications, visit PubMed

    About the Creator
    Dr. Magdy Selim