Effects of Medical High Protein Nutrition on the Muscle Mass in Adult ICU Patients

Critical illness is characterized by substantial hormone- and cytokine-mediated protein metabolism changes in various organs, leading to increased breakdown and decreased synthesis rates. Consequently, a considerable and life-threatening loss of muscle mass occurs. Medical therapeutic measures such as long-term sedation and mechanical ventilation during ICU stay can further enhance this muscle degradation (up to 2 % muscle mass per day leading to clinically relevant symptoms known as ICU-acquired weakness. Nutritional modulation, particularly of dietary amino acids, may have benefits to prevent or attenuate disease-induced muscle wasting. while there are several accurate muscle mass measurement methods and techniques [including computed tomography (CT) scan, bio-impedance analysis and ultrasound], not all are routinely feasible in clinical ICU practice. The use of ultrasound in assessing muscle mass in critically ill patients has gained much attention recently as it is non-invasive and can easily be utilized at the bedside. There are two main goals for the assessment of muscle mass: first, to assess the current muscle mass for the patient as part of (nutritional) diagnosis, and thereby risk stratification and second, to monitor the progression of muscle loss and/or recovery of muscle mass, and create opportunity to examine the effectiveness of therapeutic interventions to reduce muscle loss and/or promote muscle recovery.