Background: Venous thromboembolism is a major cause of morbidity and mortality after injury. Prophylactic anticoagulation is often delayed as a result of injuries or required procedures. Those patients at highest risk in this early vulnerable window postinjury are not well characterized. We sought to determine those patients at highest risk for an early pulmonary embolism (PE) after injury.
Methods: A retrospective analysis using data derived from a large state wide trauma registry (1997–2007) was performed. Patients with a documented PE and time of occurrence were selected (n = 712). Patients with fat emboli and lower extremity vascular injuries were excluded. Patients with a PE within the first 72 hours of admission (EARLY, n = 122) were compared with those with DELAYED presentation. Kaplan-Meier survival analysis was used to characterize the timing of death between the two groups. Backward stepwise logistic regression was used to determine independent risk factors for EARLY PE relative to those with DELAYED PE.
Results: EARLY and DELAYED groups were similar in age, gender, Glasgow Coma Scale, emergency department systolic blood pressure, and injury mechanism. The EARLY PE group had a lower Injury Severity Score but injuries more commonly included femur fracture. Kaplan-Meier analysis revealed that EARLY PE patients have a significantly higher risk of early mortality relative to DELAYED PE patients (p = 0.012). Regression analysis revealed that the only independent risk factor for EARLY PE was lower extremity/pelvic orthopedic fixation (<48 hours from injury). The risk of EARLY PE was more than threefold higher (odds ratios, 3.85; 95% CI, 1.9–7.6; p < 0.001) for those who underwent early lower extremity orthopedic fixation versus those who did not.
Conclusion: Early lower extremity/pelvis orthopedic fixation is the single independent predictor of EARLY PE in this patient cohort. Venous thromboembolism/PE prevention strategies should be made a priority in this group of patients, including early preoperative institution of anticoagulation prophylaxis. These results suggest that those with contraindications to early anticoagulation may benefit from insertion of retrievable inferior vena cava filters preoperatively.
From the Division of General Surgery and Trauma, Department of Surgery, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania.
Submitted for publication September 26, 2010.
Accepted for publication February 15, 2011.
Supported by NIH/NIGMS grant K23GM093032 and NIH grant KL2 RR024154-03 from the National Center for Research Resources (NCRR), a component of the National Institutes of Health (NIH) and NIH Roadmap for Medical Research. Information on NCRR is available at http://www.ncrr.nih.gov/. Information on Re-engineering the Clinical Research Enterprise can be obtained from http://nihroadmap.nih.gov/clinicalresearch/overview-translational.asp.
The contents of this article are solely the responsibility of the authors and do not necessarily represent the official view of NCRR or NIH.
Presented at the 69th Annual Meeting of the American Association for the Surgery of Trauma, September 22–26, 2010, in Boston, Massachusetts.
Address for reprints: Raquel M. Forsythe, MD, Division of General Surgery and Trauma, Department of Surgery, University of Pittsburgh Medical Center, 200 Lothrop Street, Pittsburgh, PA 15213; email: firstname.lastname@example.org.