Fixed Versus Variable Dosing of 4-factor Prothrombin Complex Concentrate for Emergent Warfarin Reversal

The goal of this study is to determine if a fixed dose of 4-factor prothrombin complex concentrate (4FPCC) is as effective as the current standard of care. 4FPCC is used to reverse the effects of warfarin when a patient has emergent bleeding. The investigators hope that this study will help doctors treat patients quicker in the future. In addition, it may be cheaper for patients and hospitals. This is the same medication the doctor would use to reverse warfarin's effects, but at a lower dose. Hypothesis: A fixed dose of 4FPCC will be comparable to FDA-approved variable dosing for reversal of warfarin-induced anticoagulation (defined as an international normalized ratio \[INR\] ≤ 1.5) in patients with an INR ≥2 experiencing an emergent bleed or requiring emergent surgery.