The Anticoagulated trauma patient in the age of the direct oral anticoagulants: a Canadian perspective.

BACKGROUND: The anticoagulated trauma patient presents a particular challenge to the critical care physician. Our understanding of these patients is defined and extrapolated by experience with patients on warfarin pre-injury. Today, many patients who would have been on warfarin are now prescribed the Direct Oral Anticoagulants (DOACs) a class of anticoagulants with entirely different mechanisms of action, effects on routine coagulation assays and approach to reversal.

METHODS: Trauma registry data from Toronto's (Ontario, Canada) two Level 1 trauma centres were used to identify patients on oral anticoagulation pre-injury from June 1, 2014 to June 1, 2015. The trauma registry and medical records were reviewed and used to extract demographic and clinical data.

RESULTS: We found 81 patients were on oral anticoagulants pre-injury representing 3.2% of the total trauma population and 33% of the orally anticoagulated patients were prescribed a DOAC prior to presentation. Comparison between the DOAC and warfarin groups showed similar age, mechanisms of injury, indications for anticoagulation, injury severity score and rate of intracranial hemorrhage. Patients on DOACs had higher initial mean hemoglobin vs warfarin (131 vs 120) and lower serum creatinine (94.8 vs 129.5). The percentage of patients receiving a blood transfusion in the trauma bay and total in-hospital transfusion was similar between the two groups however patients on DOACs were more likely to receive tranexamic acid vs patients on warfarin (32.1% vs 9.1%) and less likely to receive prothrombin concentrates (18.5% vs 60%). Patients on DOACs were found to have higher survival to discharge (92%) vs patients on warfarin (72%).

CONCLUSION: Patients on DOACs pre-injury now represent a significant proportion of the anticoagulated trauma population. Although they share demographic and clinical similarities with patients on warfarin, patients on DOACs may have improved outcomes despite lack of established drug reversal protocols and challenging interpretation of coagulation assays.

LEVEL OF EVIDENCE: III; Study Type: Retrospective Review.