Cumulative intraoperative oxygen exposure acts as a predictor for postoperative acute exacerbation of interstitial lung disease: a retrospective cohort study

Abstract Background Excessive oxygen administration during surgery may induce lung damage via oxidative stress; however, limited evidence exists on how intraoperative oxygen usage and preoperative pulmonary function predict acute exacerbation (AE) in patients with interstitial lung disease (ILD). This study evaluated whether intraoperative oxygen use and preoperative pulmonary function could predict postoperative AEs in patients with ILD who underwent lung surgery. Methods We retrospectively analyzed 78 patients with ILD who underwent lung surgery between 2014 and 2022. Clinical variables, including intraoperative oxygen usage and preoperative pulmonary function tests, were assessed for their association with AEs occurring within 1 month (1mAE) and 1 year (1yAE) postoperatively using Firth’s bias-reduced logistic regression. Results Eight patients (10%) had 1mAE, and 14 (18%) had 1yAE. Multivariable analysis showed that lower %vital capacity (%VC) consistently predicted both 1mAE and 1yAE, whereas lower %diffusing capacity for carbon monoxide (%DLCO) significantly predicted only 1yAE. Notably, total oxygen administration > 990 L exhibited a marginal association with 1mAE (OR 2.12, 95% CI: 0.93–4.99, p = 0.071). Even after adjusting for operative and anesthesia durations, total oxygen volume remained a significant independent predictor for 1yAE (OR 2.29, 95% CI: 1.09–4.93, p = 0.029). No significant associations were found between AEs and factors such as the mean fraction of inspired oxygen (FiO 2 ), forced expiratory volume in 1 s, sex, preoperative steroid use, computed tomography patterns, serum Krebs von den Lungen-6 levels, or surgical procedures. Conclusions Cumulative intraoperative oxygen administration (rather than mean FiO2) serves as an independent predictor of long-term postoperative AEs in patients with ILD. These findings suggest that cumulative oxygen exposure may contribute to long-term postoperative risk through mechanisms related to oxidative stress. Trial registration Aichi Medical University 2025-011.