Nutrition in ARDS, COVID-19, and ECMO

Medical nutrition therapy (MNT) represents an outcome-defining factor in the intensive care unit (ICU). During the COVID-19 pandemic, acute respiratory distress syndrome (ARDS) cases dramatically increased, making MNT in ICU even more challenging. Extracorporeal membrane oxygenation (ECMO) is a life-saving support in ARDS patients, but no specific MNT guidelines exist. Inflammation is the key pathophysiological process at the base of ARDS and COVID-19 illness. The inflammatory process increases catabolism and energy requests, thus making malnutrition in these populations extremely common and difficult to deal with. In addition, other typical characteristics of these patients need to be considered, like the high comorbidity burden and the different peculiarities of the illness phases. Invasive and noninvasive ventilation, prone position, and altered gas exchanges all influence the different aspects of MNT, such as timing for initiation of nutrition, diet type and amount, and administration route. Finally, nutritional support during ECMO becomes even more challenging, dealing with a cohort of extremely severe patients, a high risk of adverse events, and the lack of evidence. It is thus clear that MNT management should include a comprehensive knowledge of these conditions, as the right nutritional support may improve relevant clinical outcomes, like mortality and quality of life.