Preoperative Drug Monitoring in Management of Patients with Hip Fracture on Treatment with Direct Oral Anticoagulants

Purpose: Aim of the present study was to evaluate whether monitoring direct oral anticoagulant (DOAC) levels may improve management of anticoagulated patients who need surgery for hip fracture.
Patients and Methods: A total of 147 out of 2231 (7.7%) patients with hip fracture admitted to a tertiary teaching hospital were on DOACs (group A), whereas 206 patients matched for age, sex, and type of fracture not on anticoagulant or P2Y12 platelet inhibitors were considered as control group (group B). Patients on DOACs were divided into two subgroups: A1 in which intervention was scheduled in relation to the last drug intake according to current guidelines, and A2 included patients in whom time of surgery (TTS) was defined according to DOAC levels. Neuraxial anesthesia was considered with DOAC levels < 30 ng/mL, general anesthesia for levels in the range 30– 50 ng/mL.
Results and conclusions: TTS was significantly lower in controls than in DOAC patients: surgery within 48 hours was performed in 80.6% of group B versus 51% in group A (p< 0.0001). In A2, 41 patients underwent surgery within 48 hours (56%) in comparison to 32 A1 patients (45.1%; p=0.03). TTS and length of hospitalization were on average 1 day lower in patients with assay of DOAC levels. Finally, 35/39 (89%) patients with DOAC levels < 50 ng/mL had surgery within 48 hours (26 under neuraxial anesthesia, without any neurological complication, and 13 in general anesthesia).
Conclusion: DOAC assay in patients with hip fracture may be useful for correct definition of time to surgery, particularly in patients who are candidates for neuraxial anesthesia. Two-thirds of patients with DOAC levels < 50 ng/mL at 48 hours from last drug intake underwent uneventful neuraxial anesthesia, saving at least 24 hours in comparison to guidelines.

Keywords: fragility fractures, oral anticoagulants, DOAC assay, safety