Introduction: Large intracranial hemorrhages often require surgical management. For large intracranial hemorrhages associated with INR elevation due to oral anticoagulation therapy (OAT), timely evacuation of the hemorrhage provides the best chance for meaningful recovery and rapid correction of their INR is essential prior to surgical management. An understanding of the pharmacokinetics of INR reversal with fresh frozen plasma (FFP) may hasten dosing and decrease delays to life-saving surgery.
Methods: This study retrospectively evaluated the corresponding drop in INR per dose of FFP in head injury patients whose INR was being corrected with FFP. Consecutively treated patients with head trauma between January 2007 and July 2010 with INR elevation were studied (149 patients). Individual cases were assessed for FFP doses and resultant INR, as well as relevant demographic data including age, weight, height, BMI and concomitant use of Vitamin K. The change of INR relative to each administered dose of FFP was calculated, and a resultant dose-response curve produced using linear regression analysis.
Results: A linear relationship (delta INR = 0.0725(number FFP dosed) +0.927); R squared = 0.845) between INR change and FFP dose was extrapolated (FIGURE 1). No significant change in this relationship was evident when patient’s age, volume of distribution, or vitamin K administration was taken into consideration. A dose response matrix to guide FFP administration to a normal value (less than 1.4) was generated as a quick reference.
Conclusions: Our retrospective analysis of FFP dosing for correction of INR in patients on OAT with intracranial hemorrhage suggests that there is a predictable dose response relationship to units of FFP administered and concomitant decrease in INR. A dose response matrix to guide FFP administration to a normal value (less than 1.4) was generated as a quick reference for clinical use (Table 1).
Patient Care: Decrease the time required to reverse INR, which should lead to faster time to operating room and improved outcomes in TBI patient that require reversal of OAT.
Learning Objectives: Review oral anticoagulation therapy reversal (OAT), Review our proposed dosing scheme to reverse OAT