When is It Safe to Start VTE Prophylaxis After Blunt Solid Organ Injury? A Prospective Study from a Level I Trauma Center

The optimal timing of VTE prophylaxis initiation after blunt solid organ injury is controversial. Retrospective studies suggest initiation ≤48 h is safe. This prospective study examined the safety and efficacy of early VTE prophylaxis initiation after nonoperative blunt solid organ injury. All patients >15 years of age presenting after blunt trauma (12/01/16–11/30/17) were prospectively screened. Patients were included if solid organ injury (liver, spleen, kidney) was diagnosed on admission CT scan and nonoperative management was planned. ED deaths, transfers, patients with pre-existing bleeding disorders or home antiplatelet/anticoagulant medications, and those who did not receive VTE prophylaxis were excluded. Demographics, injury/clinical data, type/timing of VTE prophylaxis initiation, and outcomes were collected. Patients were dichotomized into study groups based on VTE prophylaxis initiation time: Early (≤48 h) vs Late (>48 h after admission). Prophylaxis initiation was at the discretion of the attending trauma surgeon. The primary study outcome was VTE event rate. Secondary outcomes included hospital length of stay (LOS), intensive care unit (ICU) LOS, need for and volume of post-prophylaxis blood transfusion, need for delayed (post-prophylaxis) interventional radiology (IR) or operative intervention, failure of nonoperative management, and mortality. Outcomes were compared with univariate analysis. Multivariate analysis with logistic regression determined independent predictors of late VTE prophylaxis initiation. After exclusions, 118 patients were identified. Median ISS was 22 [IQR 14–26]. Median AAST grade of injury was 2 [IQR 2–3] for liver, 2 [IQR 1–3] for spleen, and 3 [IQR 2–3] for kidney. Compared to late prophylaxis patients (n = 57, 48%), early prophylaxis patients (n = 61, 52%) had significantly fewer DVTs (n = 0, 0% vs n = 5, 9%, p = 0.024) but similar rates of PE (n = 2, 3% vs n = 3, 5%, p = 0.672). TBI was the only significant risk factor for late prophylaxis (OR 0.22, p = 0.015). No patient in either group required delayed intervention (operative or IR) for bleeding. There was no difference in volume of post-prophylaxis blood transfusion. In this prospective study of patients with nonoperative blunt solid organ injuries, early (≤48 h) initiation of VTE prophylaxis resulted in a lower incidence of DVTs without an associated increase in bleeding or need for intervention. Early initiation of VTE prophylaxis is likely to be safe and beneficial for patients with blunt solid organ injury.