M. B. Linskey1, A. B. Podany1, A. S. Kulaylat1, A. L. Lauria1, S. R. Allen1,2, J. D. Chandler1,2, R. M. Staszak1,2, S. B. Armen1,2 1Penn State University College Of Medicine,Department Of Surgery,Hershey, PA, USA 2Penn State University College Of Medicine,Division Of Trauma, Acute Care & Critical Care Surgery,Hershey, PA, USA
Introduction: Pulmonary contusions (PC) lead to morbidity and mortality in trauma patients, placing them at increased risk for mechanical ventilation, acute respiratory distress syndrome, and pneumonia. Tissue injury and hemorrhage in PC result in inflammation, edema, atelectasis, and intrapulmonary shunting even in the uninjured lung. We hypothesized that early prophylactic anticoagulation (pAC) would be associated with worsened respiratory outcomes in patients with PC.
Methods: A retrospective cohort study identified patients with PC from a rural Level I trauma center’s institutional registry. Patients with severe traumatic brain injury, prior use of therapeutic anticoagulation or antiplatelet therapy, and those who did not receive pAC were excluded. The cohort was stratified into those receiving early or delayed pAC, within or after 48 hours of admission, respectively. Outcomes including 30-day mortality, 30-day venous thromboembolism (VTE) rate, retained hemothorax, and pneumonia were modeled using multivariable logistic regression to control for patient and injury characteristics. Propensity score matching was then used to isolate two groups with similar comorbidities and injuries. Univariate statistics were performed to compare nadir oxygen saturation levels and supplemental oxygen requirements between the two groups before and after administration of pAC.
Results: 356 patients met inclusion criteria; 195 in the early and 161 in the delayed groups. The groups did not differ with respect to age, sex, race, mechanism, pulmonary comorbidities, number of rib fractures, or proportion with flail chest. The group receiving delayed pAC had lower admission GCS scores (12.0 vs 14.1, p<0.001) and higher injury severity scores (27.7 vs 20.0, p<0.001), and was significantly more likely to have bilateral PC (41.3% vs 28.4%, p<0.05), concomitant solid organ injury (42.2% vs 12.8%, p<0.001), intracranial or spinal hematoma (35.4% vs 5.64%, p<0.001), or other organ space hematoma (28.0% vs 14.9%, p<0.01). After controlling for differences between the groups, initiation of pAC within 48 hours of injury in patients with PC did not significantly increase the odds of 30-day mortality. Similarly, early pAC was not significantly associated with retained hemothorax or pneumonia. Delayed pAC was also not associated with VTE. Of the propensity score-matched groups, those with early pAC had a decrease between their pre- and post-pAC nadir oxygen saturation levels while those with delayed pAC had a slight increase (93.2% to 90.1% among early vs 90.9 to 92.1% among delayed, p<0.001). Changes in oxygen requirements before and after pAC, however, did not differ between the two groups (37% to 28% among early vs 36% to 25% among delayed, p=0.401).
Conclusion: In this study, early vs delayed pAC did not significantly impact outcomes in patients with PC, suggesting that other clinical factors should guide timing of pAC in adult trauma patients.