Preoperative Pneumonia and Postoperative Venous Thrombosis: A Cohort Study of 427,656 Patients Undergoing Major General Surgery.

ABSTRACT

BACKGROUND: The literature is sparse regarding the association between pneumonia and venous thrombosis in surgical patients. The aim of this study was to investigate the risk of postoperative venous thrombosis in patients who fit the criteria for preoperative pneumonia using data from the ongoing American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) database while adjusting for potential confounders. METHODS: This is a cohort study using data from the ACS NSQIP database participating sites from 2008 (211 sites) and 2009 (237 sites). 427,656 patients undergoing major general surgery were included. The 30-day risk of postoperative venous thrombosis including deep vein thrombosis (DVT) and pulmonary embolism (PE) was evaluated in patients with preoperative pneumonia diagnosed before undergoing major general surgery. RESULTS: Patients with preoperative pneumonia had a higher incidence of both 30-day DVT and PE than patients without preoperative pneumonia. After adjusting for all potential confounders, the effect estimates for the association between preoperative pneumonia and venous thrombosis were DVT, OR 1.67 (95% CI 1.32-2.11) and PE, OR 2.18 (95% CI 1.48-3.22). CONCLUSIONS: A large, multicenter database of surgical patients showed that preoperative pneumonia may increase risk for developing venous thrombosis. This adds to our understanding of risk factors for venous thrombosis and suggests a potential benefit of diagnosing preoperative pneumonia in patients undergoing major general surgery.