A Nationwide Analysis on the Origins of De Novo Pulmonary Embolism in Trauma Patients: Does the Liver Play a Role?

Abstract

INTRODUCTION: The trauma literature coined the concept of de novo pulmonary embolism (DNPE) to describe the presence of pulmonary embolism without deep vein thrombosis. Most surmise DNPE stems from localized pulmonary inflammatory changes (Figure). Considering the liver’s proximity to the lungs and its importance in inflammation and coagulation, our team published previous institutional data suggesting liver injury may play a central role in DNPE formation. The purpose of this study was to validate the relationship between liver injury and DNPE using a national trauma database.Figure.: DNPE, de novo pulmonary embolism.METHODS: We identified all blunt trauma patients in the National Trauma Data Bank 2018 dataset. Patients were divided and compared based on whether they suffered liver injury. Our primary outcome was the incidence of DNPE, defined as pulmonary embolism in the absence of deep vein thrombosis. Patients without peripheral duplex studies were excluded. Multivariate regression was used to identify independent risk factors for DNPE formation. RESULTS: In total, we identified 26,592 patients. Compared with non–liver injury patients, liver injury patients had a higher incidence of DNPE (3.4% vs 1.6%; p < 0.05). On multivariate analysis, increased Injury Severity Score (odds ratio [OR] 2.8), Black race (OR 2.1), liver injury (OR 1.9), and multiple bilateral rib fractures (OR 1.6) were independent predictors of DNPE formation. CONCLUSION: This is the first nationwide review to implicate liver injury as a contributing factor in DNPE. Based on our findings, we propose a model for de novo clot formation that involves localized trauma as well as regional thromboembolic and systemic effects of liver injury and polytrauma.