Epidemiology of continuous renal replacement therapy in critically ill adults on ECMO: A multicenter cohort study

The clinical implications of continuous renal replacement therapy (CRRT) in patients receiving extracorporeal membrane oxygenation (ECMO) remain incompletely characterized. We investigated the association of CRRT exposure and its timing relative to ECMO cannulation with in-hospital mortality and renal recovery.

Retrospective multicenter cohort study (2009-2023) of adults receiving ECMO. Patients were categorized as CRRT-before (≤7 days before ECMO cannulation), CRRT-early (<48 h after cannulation), CRRT-late (48 h-14 days after cannulation), or ECMO-only. The primary outcome was in-hospital mortality. Multivariable logistic regression analysis was performed overall and after stratification by ECMO configuration (veno-arterial [VA] or VA + veno-venous [VV] vs. VV).

Among 1358 ECMO patients, 512 (37.7%) received CRRT: 82 CRRT-before, 234 CRRT-early and 196 CRRT-late. Overall, 61.49%, 36.6%, and 1.91% of patients received VA-ECMO, VV-ECMO, and both VA- and VV-ECMO, respectively. In-hospital mortality was 35.22% in ECMO-only patients, 74.39% in CRRT-before, 64.96% in CRRT-early, and 66.33% in CRRT-late. Compared with ECMO-only, CRRT exposure was independently associated with higher in-hospital mortality (CRRT-before: aOR 4.95, 95%CI 2.62-9.35; CRRT-early: aOR 3.10, 95%CI 2.14-4.50; CRRT-late: aOR 4.08, 95%CI 2.82-5.89). Older age, sepsis, and VA-ECMO were independent predictors of mortality. ECMO survivors who were exposed to VA-ECMO and CRRT had a higher rate of RRT dependence at discharge when compared with those who received VV-ECMO and CRRT (71.15% vs. 46.15%).

In this multicenter ECMO-cohort, CRRT was independently associated with higher in-hospital mortality regardless of ECMO configuration and the timing of CRRT initiation.