Impact of measurement of direct oral anticoagulants on time to surgery for patients with hip fracture: a retrospective cohort study
Aim: To evaluate whether the use of levels would reduce time to hip fracture surgery in patients using direct oral anticoagulants (DOAC)
Methods: During the period from 2017-2020, a DOAC protocol was gradually implemented in the unit using DOAC levels and thrombin clotting time prior to hip fracture surgery, proceeding to surgery if the tests were below a pre-specified level. Patients were separated into two cohorts based on whether DOAC levels were tested prior to surgery (n=34) or were not tested (n=18). The primary outcome, time to surgery, was calculated from presentation time at the emergency department to surgery. Secondary outcomes included blood loss as measured by blood transfusion rate, thromboembolic complications and medical complications.
Results: There was no significant difference in time to surgery between the two cohorts of patients (p=0.943). Eleven patients (32%) with pre-operative DOAC levels and six patients (33%) without DOAC levels had time to surgery of >48 hours. The cohorts also showed no significant differences in baseline characteristics, haemoglobin drop, blood transfusion rate, and medical complications, though analysis was limited by the small number of patients in the groups. Possible benefit was suggested through analysing a hypothetical optimum scenario where surgery was performed within two hours once the pre-specified DOAC threshold was met.
Conclusion: Pre-operative testing of DOAC levels did not alter time to hip fracture surgery in this study. Further research is required to explore the possible benefits of pre-operative DOAC levels in hip fracture management.