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  • Mild Elevations of INR Are Not Associated with Significantly Increased Risk in Coumadin-associated Subdural Hematoma

    Final Number:

    Marie Roguski MD; Julian K. Wu MD

    Study Design:
    Clinical Trial

    Subject Category:

    Meeting: Congress of Neurological Surgeons 2012 Annual Meeting

    Introduction: A primary goal in the treatment of patients with coumadin-associated subdural hematoma (SDH) is reversal of coagulopathy with fresh frozen plasma. Achieving the traditional target INR of 1.3 is often difficult and exposes high risk patients to risks of volume overload and thromboembolic complications. This study evaluates the risk of mild elevations of INR from 1.3-1.7 in patients presenting with coumadin-associated SDH.

    Methods: 57 patients with coumadin-associated SDH and 193 patients with non-coumadin associated SDH treated at a single institution from January 2005 through March 2011 were retrospectively identified. Charts were reviewed for age, associated injuries, neurological status at presentation, size and chronicity of SDH, associated midline shift, INR at admission and at hospital day 1 (HD1), concomitant aspirin or plavix use, platelet count, and for medical comorbidities. Patients were stratified according to use of coumadin and by INR at HD1 (INR 0.8-1.3, 1.31-1.69, 1.7-1.99, and >2). The groups were evaluated for differences in rate of radiographic expansion of SDH and for differences in rate of SDH expansion resulting in death, unplanned procedure, and/or readmission.

    Results: There was no difference in rate of radiographic expansion or significant expansion of SDH between patients on coumadin and not on coumadin (22.3% vs. 21.1%, p=0.64; 10.9-10.5%, p=0.62), but the rate of medical complications was significantly higher in the coumadin subgroup (29.8% vs 13.6%, p=0.0086). There was no difference in radiographic or significant expansion between patients with HD1 INR between 0.8-1.3 and 1.3-1.69. For coumadin-associated SDH, there was no difference between radiographic and significant expansion for patients reversed to a HD1 INR between 0.8-1.3 and 1.3-1.69 (20.6% vs 25%, p=0.75; 11.8% vs. 12.5%, p=1).

    Conclusions: Mild INR elevations of 1.3-1.69 in coumadin-associated SDH are not associated with a markedly increased risk of radiographic or clinically significant expansion of SDH.

    Patient Care: Subdural hematoma is a common condition treated by neurosurgeons. Coumadin use is a known risk factor for SDH, and reversal of coumadin-associated coagulopathy is a primary goal in treatment of coumadin-associated coagulopathy. An INR of less than 1.3 has been chosen somewhat arbitrarily as the goal for complete reversal of coagulopathy. Unfortunately, achieving this goal is often much more difficult than reversal to INR between 1.4-1.6, and, in some situations, exposes high risk patients to additional risk of volume overload and thromboembolic complications. This study offers some evidence that mild elevations of INR to 1.4-1.6 at hospital day 1 may not be associated with significantly increased risk of SDH expansion. This finding may reduce the risk of FFP transfusion-associated complications in select high risk patients with coumadin-associated SDH.

    Learning Objectives: By the conclusion of this session, participants should be able to: 1) Describe the importance of reversal of coagulopathy in patients with coumadin-associated subdural hemorrhage, 2) Discuss, in small groups, the benefits and risks of reversal of coagulopathy in patients with coumadin-associated SDH, 3) Identify clinical situations in which reversal of INR to a goal of less than 1.69 may be warranted based on individual patient risk factors, and 4) Recognize the need for a prospective randomized trial to identify the optimal target INR for reversal of coumadin-associated SDH.


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