Effect of Intra- and Postoperative Fluid and Blood Volume on Postoperative Pulmonary Edema in Patients With Intraoperative Massive Bleeding: Multi-Center Cohort Study Using Time Varying Analysis

BackgroundIn patients with massive bleeding during surgery, the effect of intra- and postoperative fluid and blood volume on postoperative pulmonary edema is uncertain. The aim of this study is evaluating the occurrence risk relationship through time-varying analysis between postoperative pulmonary edema and intra- and postoperatively administered volume of fluid and blood in patients with intraoperative massive bleeding.MethodsThis study is a retrospective cohort study and data was obtained from the clinical data warehouse at Hallym University Medical Center, a multi-institutional data registry of 5 hospitals of Hallym University. Patients with intraoperative massive bleeding (≥40% of average blood volume) and who underwent a non-cardiac surgery at 5 hospitals between January 1, 2010, and December 31, 2019 were enrolled the study. The primary outcome was postoperative pulmonary edema occurrence within 72 hours after surgery. Secondary outcomes were postoperative pulmonary edema with hypoxemia. ResultsIn total, 2090 patients were included in the postoperative pulmonary edema analysis, and 300 patients developed pulmonary edema within 72 hours after surgery. The postoperative pulmonary edema hypoxemia analysis with hypoxia included 1660 patients; pulmonary edema with hypoxemia occurred in 161 patients. The increase in the amount of red blood cells/average blood volume/hour after surgery increased the risk of developing pulmonary edema after surgery (hazard ratio: 1.03, 95% confidence interval [1.01–1.05], P = 0.013) and the risk of developing pulmonary edema with hypoxemia (hazard ratio: 1.04, 95% confidence interval [1.01–1.07], P = 0.024).Conclusion In this study, an increase in the transfusion of red blood cells per hour after surgery increased the risk of developing pulmonary edema after surgery. This increase can be considered a risk factor for the incidence of pulmonary edema.