It's all in your head: Safety of weight-based, targeted enoxaparin prophylaxis in intracranial hemorrhage patients.

Abstract

Prior studies have demonstrated that 30-mg twice-daily enoxaparin dosing is inferior to weight-based, anti-Xa-targeted dosing for venous thromboembolism prophylaxis in trauma patients. Despite this, many trauma guidelines continue to support universal low-dose enoxaparin (30 mg twice daily) in patients with traumatic brain injury for fear of expansion of intracranial hemorrhage and adverse neurologic outcomes. We hypothesized that weight-based, anti-Xa-targeted dosing is safe in trauma patients with intracranial hemorrhage. We retrospectively reviewed patients admitted to a level 1 trauma center with intracranial hemorrhage from 2015 to 2022. Intracranial hemorrhage patients who received weight-based subcutaneous enoxaparin dosing (50-59 kg, 30 mg twice daily; 60-99 kg, 40 mg twice daily; ≥100 kg, 50 mg twice daily) and had a peak anti-Xa level assessed (goal 0.2-0.4 IU/mL) were included. Enoxaparin was cleared to start 48 hours after a stable head computed tomography. Charts were reviewed to assess for intracranial hemorrhage expansion after initiation of enoxaparin. Of the 509 intracranial hemorrhage patients included, there were 8 patients (1.6%) with intracranial hemorrhage expansion. Of patients given enoxaparin 30 mg twice daily, 1 (1.8%) developed intracranial hemorrhage expansion; the patient also had an initial supra-prophylactic anti-Xa level. Seven patients (1.7%) administered 40 mg twice daily developed intracranial hemorrhage expansion; none of these patients were supra-prophylactic according to their anti-Xa levels. No patients given 50 mg developed intracranial hemorrhage expansion after enoxaparin initiation. In this single-center retrospective study, initial weight-based enoxaparin dosing in patients with stable intracranial hemorrhages did not result in significant clinical neurologic deterioration, directly challenging current venous thromboembolism prophylaxis guidelines for patients with traumatic brain injury. These results should serve as a platform for multicenter prospective data collection to ultimately determine the safety and efficacy of weight-based enoxaparin prophylaxis regimens in traumatic brain injury patients.