Feeding under support in critical care illness: metabolic and nutritional management during extracorporeal membrane oxygenation and continuous renal replacement therapy

PURPOSE OF REVIEW: The use of life-support therapies like extracorporeal membrane oxygenation (ECMO), mechanical circulatory systems (MCS), and continuous renal replacement therapy (CRRT) creates a complex and dynamic metabolic environment that profoundly challenges nutritional management for these critically ill patients. Current existing guideline recommendations are largely based on expert opinions and observational data. No specific guidelines exist for this population. RECENT FINDINGS: This mini-review synthesizes the current, limited evidence on the pathophysiological and metabolic alterations induced by ECMO, MCS, and CRRT and provides pragmatic recommendations for nutritional assessment and delivery. SUMMARY: The key challenges include dramatic nutrient fluxes in the case of CRRT, a possible hypermetabolic state exacerbated by ECMO, fluid overload constraints, and drug-nutrient interactions. Practical strategies are proposed for calorie-protein targeting, micronutrient repletion, and monitoring, emphasizing a 'start low, advance carefully' approach within a multidisciplinary framework.