- Direct oral factor Xa (FXa) inhibitors are widely used for anticoagulation but a targeted antidote is not available. Four-factor prothrombin complex concentrate (4FPCC) has been shown in observational studies to support hemostasis in most patients with major bleeding related to FXa inhibitors with an acceptable rate of thromboembolic events. However, the effectiveness of 4FPCC for reversal of FXa inhibitors prior to emergency surgery or invasive procedures is unclear. A retrospective chart review was performed in patients that received 4FPCC at Hamilton General Hospital from 2015 to 2017. The primary effectiveness outcome was based on the comment of the surgeon on the adequacy of the hemostasis. If no such comment was documented, the case was discussed with a surgeon specialized in the type of surgery/procedure performed to obtain their best opinion. The principal safety outcome was thromboembolic events including venous thromboembolism, ischemic stroke, systemic embolism or myocardial infarction during 7 days after surgery. A total of 247 patients that had received 4FPCC were initially screened and 21 were on a FXa inhibitor and had emergency surgery/procedure. The mean age was 74 ± 11 years, and 14 (66.7%) were males. Hemostasis was rated as good in most patients (18 of 21, 85.7%). There were no thromboembolic events. The all-cause mortality rate was 28.6%; 2/3 of these patients had an intracranial hemorrhage. Hemostasis was rated as good in most patients with no thromboembolic events observed. Prospective studies assessing the safety and effectiveness of 4FPCC for this indication are needed.