Pulmonary Artery Thrombosis in Trauma: Not as Deadly as Previously Thought.

Abstract

Background: Pulmonary embolism (PE) is a well-known morbid and potentially life-threatening complication of polytrauma. There is growing evidence to suggest that patients with trauma are suspected to be prone to in situ pulmonary artery thrombosis (PAT) as a consequence of trauma-induced coagulopathy and endotheliopathy in addition to the classic PE preceded by deep venous thrombosis (DVT). Whether PAT on admission requires attention or can be safely ignored is currently unknown. This study aims to characterize the incidence, risk factors, and clinical outcomes of PAT in all patients with trauma admitted via the trauma resuscitation bay.

Methods: This study is a 1-year retrospective study of patients admitted to a Level 1 Trauma Center in 2019. All initial trauma scans were retrospectively reviewed by a radiologist to assess for the presence of any visible clots in the pulmonary vasculature on admission. PAT was defined as pulmonary clots identified on the initial trauma pan-scan, PE was defined as a pulmonary clot detected on CTPA performed for diagnosis of suspected PE. The primary outcome was the identification of a pulmonary clot. Secondary outcomes were mortality, length of stay in intensive care unit (ICU), overall length of stay, number of days requiring ventilation, development of respiratory failure, multiple organ failure (MOF), and its association with polytrauma.

Results: Of the 597 patients admitted, 278 (46.6%) patients had CT chest with IV contrast during admission and were included in this study. 45/278 (16.2%) patients were identified to have pulmonary clots; 43 (15.5%) were PAT and 2 (0.7%) were PE. There was no significant difference in the patient population or ISS between groups. PAT was associated with higher AIS scores in the extremities (p = 0.004) and external (p = 0.006) body regions. PAT was also associated with shock on presentation with lower systolic (p = 0.004) and diastolic blood pressure (p = 0.015) and elevated lactate (p = 0.002). PAT was associated with the development of early respiratory failure (p = 0.004). There was no difference in ICU admission or ventilator requirements.

Conclusion: In conclusion, this study demonstrates that post-trauma PAT is frequently identified on initial trauma imaging and is associated with early respiratory failure, shock on presentation, and extremity trauma but not with injury severity, mortality or intensive care admission. This study will inform future prospective studies on power and design to identify predictors for adverse outcomes and potential causal relationships with the risk factors identified.