Thromboembolic prophylaxis with low-molecular-weight heparin in patients with blunt solid abdominal organ injuries undergoing nonoperative management: current practice and outcomes

Abstract

Background: Low-molecular-weight heparins (LMWHs) are effective in preventing thromboembolic complications after trauma. In the nonoperative management (NOM) of blunt solid abdominal organ injuries, the timing of the administration of LMWH remains controversial because of the unknown risk for bleeding.

Methods: Retrospective study including patients aged 15 years or older who sustained blunt splenic, liver, and/or kidney injuries from January 2005 to December 2008. Patients were stratified according to the type and severity of organ injuries. NOM failure rates and blood transfusion requirements were compared between patients who got LMWH early (≤3 days), patients who got LMWH late (>3 days), and patients who did not receive LMWH.

Results: Overall, 312 (63.8%) patients with solid organ injuries had NOM attempted. There were 154 splenic, 144 liver, and 65 kidney injuries (1.2 organs injured per patient). Forty-one patients (13.2%) received LMWH early, 70 patients (22.4%) received LMWH late, and 201 (64.4%) patients did not receive LMWH. The early LMWH group was less severely injured compared with the late LMWH group. However, the distribution of the risk factors for failure of NOM (high-grade injury, large amount of hemoperitoneum, and contrast extravasation) was similar between the three LMWH groups. Overall, 17 of 312 patients (5.4%) failed NOM (7.8% spleen, 2.1% liver, and 3.1% kidney). All but one failure occurred before LMWH administration. After adjustment for demographic differences, the overall blood transfusion requirements for the early LMWH group was significantly lower when compared with patients with late LMWH administration (3.0±5.3 units vs. 6.4±9.9 units; adjusted p=0.027). Pulmonary embolism and deep venous thrombosis occurred in four patients. The mortality rate for patients with splenic, liver, and kidney injuries was 3.2% and did not differ with LMWH application.

Conclusion: In patients with solid abdominal organ injuries undergoing NOM, early use of LMWH does not seem to increase failure rates or blood transfusion requirements.