Acute kidney injury (AKI) is frequent in patients supported with venoarterial extracorporeal membrane oxygenation (VA-ECMO), largely due to the severity of cardiogenic shock and multiorgan failure. Renal replacement therapy (RRT) can be delivered either via an indwelling catheter (parallel system, PS) or through direct connection to the ECMO circuit (integrated system, IS). Their respective safety profiles, particularly regarding infectious, hemorrhagic, and circuit-related complications, remain insufficiently characterized.

We conducted a single-center retrospective analysis of prospectively collected data from consecutive adults who received RRT for ≥24 h while on VA-ECMO between 2006 and 2019. Complications occurring during the concomitant ECMO–RRT period were compared between IS and PS configurations.

Eighty patients (84 procedures: 42 IS, 42 PS) were included. Infectious complications occurred in 31% of IS procedures and 45.2% of PS procedures, with earlier onset in the PS group (3 vs 5 days; p = 0.048). However, in multivariable analysis, IS was not independently associated with reduced infection risk (OR 0.67 [0.27-1.70]; p = 0.421). Hemorrhagic events (54.8% IS vs 59.5% PS) and circuit dysfunctions, including filter clotting, were comparable between groups.

In VA-ECMO patients requiring RRT, integrated and parallel configurations demonstrate similar safety profiles with no significant differences in infectious, hemorrhagic, or circuit-related complications. These findings support selecting the RRT configuration based primarily on local expertise and technical feasibility rather than expected differences in complication risk