Continuous High Positive-End Expiratory Pressure May Worsen Renal Function in Patients With Acute Respiratory Distress Syndrome: Retrospective Analyses of a Nationwide, Multicenter Observational Study in Japan

Background: Positive end-expiratory pressure (PEEP), especially continuous high PEEP, is thought to be a risk factor for worsening renal function (WRF) due to impaired venous return and the development of renal interstitial edema. In this study, we investigated whether PEEP is a risk factor for WRF in patients with acute respiratory distress syndrome (ARDS), a representative pathology that requires continuous high PEEP for respiratory management. Methods: We performed retrospective sub-analyses of the Japanese Association for Acute Medicine, a nationwide prospective observational registry of ARDS (FORECAST ARDS registry) prospective multicenter cohort study. WRF was defined on the basis of a worsening renal Sequential Organ Failure Assessment (SOFA) score. We performed univariate and multivariable analyses to identify possible risk factors for WRF, and propensity score analyses to compare the frequency of WRF according to cutoff values for the difference in PEEP between day 1 and day 4. Results: We analyzed 151 cases. Multivariable analysis showed that the difference in PEEP (odds ratio (OR) 1.123 (95% confidence interval (CI) 1.017-1.240), P = 0.022) and male sex (OR 3.287 (95% CI 1.029-10.502), P = 0.045) were risk factors for WRF. Propensity score analysis showed trends towards an increased risk for WRF in each cutoff value for the difference in PEEP: −5 cmH(2)O (OR 0.389 (95% CI 0.084-1.799), P = 0.229), 0 cmH(2)O (OR 2.222 (95% CI 0.755-6.540), P = 0.150), and 5 cmH(2)O (OR 3.277 (95% CI 0.940-11.425), P = 0.065). Conclusions: This study revealed that the difference in PEEP between days 1 and 4 was positively associated with WRF. However, a significant cutoff value for the difference in PEEP was not determined.