Risk factors for mortality in patients with sepsis on extracorporeal membrane oxygenation and/or continuous renal replacement therapy: a retrospective cohort study based on MIMIC-IV database

Abstract

Objective This study aimed to identify risk factors for mortality in septic patients undergoing extracorporeal membrane oxygenation (ECMO) and/or continuous renal replacement therapy (CRRT). Methods Data from the MIMIC-IV database were retrospectively reviewed for 24,502 septic patients treated with ECMO or CRRT between 2008 and 2019. After applying inclusion and exclusion criteria, 70 patients receiving ECMO, 513 receiving CRRT, and 22 receiving both were included in the final analysis. Univariate and multivariate stepwise Cox regression analyses were performed to identify independent risk factors for mortality. Model performance was assessed using receiver operating characteristic (ROC) curve analysis. We also provided model-agnostic explanations for each Cox regression model. Results For septic patients on ECMO, prothrombin time (per 1-s increase, HR 1.037, 95% CI 1.007–1.068, p = .015) was the key independent risk factor. For septic patients undergoing CRRT, SOFA score (per one-point increase, HR 1.100, 95% CI 1.055–1.147, p < .001) was the most significant factor. For septic patients requiring both ECMO and CRRT, prior history of hypertension (HR 4.342, 95% CI 1.332–14.153, p = .015) was the sole independent risk factor. ROC analysis showed satisfactory model performance (AUC > 0.75). Conclusion For septic patients requiring ECMO, prothrombin time was the key independent risk factor. For those needing CRRT, SOFA score was the most significant independent risk factor. Prior history of hypertension was the primary independent risk factor for septic patients needing both CRRT and ECMO.