Extracorporeal Membrane Oxygenation and Continuous Renal Replacement Therapy in Adults and Children

The lung and kidney are among the most frequently involved organs in critically ill patients with multi-organ failure (MOF) syndrome, a progressive dysfunction of two or more organ systems after an acute threat to systemic homeostasis. Up to 60% of patients with MOF and respiratory support need renal replacement therapy (RRT) and, on the other hand, the majority of critically ill patients with severe acute kidney injury (AKI) develop an increased risk of death as a result of extrarenal complications, including respiratory failure.

Over the last 10 years, thanks to a significant improvement in the capacity to support MOF through extracorporeal techniques, the so-called multi-organ support therapy (MOST) has been hypothesized and practically realized. In this light, the extracorporeal membrane oxygenation (ECMO) circuit, applied for lung support, may serve as a platform for additional organ support therapies in adults and children. In addition, regardless of respiratory function, because of the heart-kidney cross-talk (i.e., cardiorenal syndromes), renal failure is very likely and continuous RRT (CRRT) frequently is applied in patients with cardiogenic shock needing an extracorporeal support (venous-arterial extracorporeal membrane oxygenation, [VA-ECMO]), or extracorporeal life support, ECLS). ECMO typically is employed as a temporary support, awaiting recovery of organ function or as bridge to an alternative therapy (e.g., organ transplantation or ventricular assist devices). AKI is a major comorbid condition in patients undergoing extracorporeal support, affecting up to 70% of ECMO patients, although incidences may vary because of the differences of AKI definitions.

The present chapter focuses on theoretical and practical aspects of renal replacement techniques combined with ECMO in adult and pediatric patients with respiratory, cardiac, or cardiorespiratory insufficiency. Methodology, feasibility, efficacy, safety, and outcome measures of the combination of these two types of therapies are addressed.