Skeletal muscle has an important role in the structural maintenance of the body and movement , as well as immunological and metabolic functions that facilitate the body ’ s ability to respond and recover from illness 3 . In critical illness , rapid and significant losses of skeletal muscle have been observed and associated with worsening physical function and strength 4-6 . This muscle wasting is the result of muscle protein breakdown exceeding muscle protein synthesis . While mechanisms driving this breakdown are largely unknown , altered substrate metabolism , anabolic resistance , and immobilisation are all thought to contribute 7 .
Skeletal muscle mass is highly responsive to nutrition and physical therapy interventions 8 . This article focuses on the potential role of nutrition in attenuating muscle loss in critical illness .
Nutrition delivery during the continuum of critical illness
While in the ICU , patients receive less nutrition than prescribed and recommended in international clinical guidelines primarily due to delayed initiation , gastrointestinal intolerance , and fasting for procedures 9 . There is a growing body of evidence demonstrating that nutrition delivery remains compromised when patients are discharged to the ward , compounded by the early removal of nasogastric tubes , poor appetite , taste changes , and swallowing difficulties 10 . As a result , critically ill patients are at high risk of significant cumulative deficits in energy and protein delivery throughout the whole hospital admission , which may negatively impact muscle mass .