Abstract
Introduction
Early surgery for hip fractures is beneficial but is often delayed by anticoagulation. Direct acting anticoagulants (DOAC), Rivaroxaban and Apixiban, are increasingly used in primary and secondary care but there is no specific reversal agent. Current guidance is to delay surgery 48 hours. Anti-factorXa levels < 80 ug/l are considered safe for major surgery and for spinal anaesthesia. We investigated if delay in this cohort of patients can be predicted or reduced.
Patients/Materials & Methods
41 consecutive patients presenting with a hip fracture on therapeutic dose DOAC were identified. Anti- factorXa levels were collected at 24hours and repeated at 48hours if elevated. We investigated if renal function or clotting screen could help predict safe time to surgery.
Results
36/41 had levels taken at 24 hours. Of these 21 (58%) had levels of 80 ug/l of less (<30 – 80). The remaining 15 (42%) had elevated levels at 24hours (85–224). One patient had levels greater than 80 ug/l at 48 hours. Clearance rate did not differ between Rivaroxaban and Apixiban. There was no significant difference in the prothrombin time (PT) between groups. Mean PT was 12.1 (10.6 – 15.1) for patients with levels <80ug/l and 13.4 ug/l (11.9– 15.6) for those patients with levels >80ug/l. Renal function affected drug clearance with a mean eGFR of 61 ml/min/1.73m2 (31–>90) in those with levels <80ug/l compared to 51 ml/min/1.73m2 (29–86) in those with levels >80ug/l
Discussion
Drug clearance of DOACS is un-predictable and standard clotting screens cannot be used for assessment. Approximately 40% will still have high levels at 24 hours. Patients with renal impairment are more likely to possess high levels at 24 hours. Operating based on time from last dose could be associated with a bleeding risk or conversely delay surgery inappropriately.
Conclusion
The measurement of Anti- factorXa levels could enable safe early surgery in the majority of patients.
