The aim of the study is to monitor and evaluate changes in body composition, with a special emphasis on muscle mass, in the context of polyneuromyopathy of critically-ill patients at ICU, on artificial ventilation (duration of artificial ventilation at least 7 days), and subsequent comparison with the patient's condition in 12 weeks, as a part of Post-Intensive Care Syndrome (PICS) monitoring. The effect of the package (nutritional recommendations + physiotherapy protocol vs. standard of care) will be evaluated.