Protein nutrition and functional outcomes in critical illness

Patients admitted to the intensive care unit are critically ill and can lose a tremendous amount of muscle mass in only a few days, which in turn can lead to long-term muscle weakness and delayed recovery. This thesis investigated the role of protein nutrition, as dietary protein is important in health to maintain muscle mass and function. Using isotopically labelled nutrition, this thesis found that providing nutrition with free amino acids rather than intact protein (i.e. a sort of pre-digested protein) leads to better uptake of dietary protein in critically ill patients. This thesis also investigated the impact of an ICU admission in severe COVID19 infection and found that at 3 months following an ICU admission for COVID19, patients were still subject to severe muscle weakness, significant lung disease and impaire fysical function. Future work should integrate dietary protein interventions and functional outcomes to improve recovery of ICU patients.