Safely combining renal replacement therapy and extracorporeal membrane oxygenation

Extracorporeal membrane oxygenation (ECMO) is an extracorporeal technique used in acute circulatory and respiratory failures refractory to conventional therapies. ECMO patients are at risk of developing severe acute kidney injury, with approximately 50% requiring renal replacement therapy (RRT). Different combinations of RRT and ECMO circuits have been reported: RRT can be performed independently using a specific vascular access or directly integrated into the ECMO circuit. The use of an integrated combination may reduce the risk of vascular access-related complications. However, a comprehensive knowledge of both extracorporeal therapies is required to optimize the management of an integrated combination. We report herein how to safely combine the RRT and ECMO circuits using Cardiohelp® and Xenios® consoles. We suggest connecting RRT on the positive pressure sections of the ECMO circuit, with the return line placed before the oxygenator and without modification of the ECMO circuit. This configuration minimizes the risk of air embolism in the circuit, while the oxygenator prevents any arterial air embolism from entering the patient's circulation. We also outline the factors influencing RRT circuit pressures to assist physicians in effectively managing elevated pressures within the RRT circuit. Last, we explain other combinations of RRT and ECMO that can be performed on other ECMO circuits in case of high pressures.