title: Proteins and amino acids are fundamental to optimal nutrition support in critically ill patients.
abstract: Proteins and amino acids are widely considered to be subcomponents in nutritional support. However, proteins and amino acids are fundamental to recovery and survival, not only for their ability to preserve active tissue (protein) mass but also for a variety of other functions. Understanding the optimal amount of protein intake during nutritional support is therefore fundamental to appropriate clinical care. Although the body adapts in some ways to starvation, metabolic stress in patients causes increased protein turnover and loss of lean body mass. In this review, we present the growing scientific evidence showing the importance of protein and amino acid provision in nutritional support and their impact on preservation of muscle mass and patient outcomes. Studies identifying optimal dosing for proteins and amino acids are not currently available. We discuss the challenges physicians face in administering the optimal amount of protein and amino acids. We present protein-related nutrition concepts, including adaptation to starvation and stress, anabolic resistance, and potential adverse effects of amino acid provision. We describe the methods for assessment of protein status, and outcomes related to protein nutritional support for critically ill patients. The identification of a protein target for individual critically ill patients is crucial for outcomes, particularly for specific subpopulations, such as obese and older patients. Additional research is urgently needed to address these issues.
authors.affiliation: Department of Nutrition and Dietetics, Internal Medicine, VU University Medical Center Amsterdam, De Boelelaan 1117, 1081 HV, Amsterdam, the Netherlands. p.weijs@vumc.nl.|Department of Intensive Care Medicine, VU University Medical Center Amsterdam, De Boelelaan 1117, 1081 HV, Amsterdam, the Netherlands. p.weijs@vumc.nl.|Department of Nutrition and Dietetics, Amsterdam University of Applied Sciences, Wibautstraat 2-4 1091 GM, Amsterdam, the Netherlands. p.weijs@vumc.nl.|EMGO+ Institute of Health and Care Research, VU University Medical Center Amsterdam, De Boelelaan 1117, 1081 HV, Amsterdam, the Netherlands. p.weijs@vumc.nl.
authors.forename: Peter J M
authors.initials: PJ
authors.lastname: Weijs
authors.affiliation: Clinical Chemistry Department, Cochin and Hôtel-Dieu Hospitals, APHP, 1 place du Parvis Notre-Dame 75004, Paris, France. luc.cynober@cch.aphp.fr.|Nutrition Lab, EA 4466, Department of Experimental, Metabolic and Clinical Biology, Faculty of Pharmacy, Paris Descartes University, 12 rue de l'Ecole de Médicine 75270, Paris, France. luc.cynober@cch.aphp.fr.
authors.forename: Luc
authors.initials: L
authors.lastname: Cynober
authors.affiliation: Baxter Healthcare, Deerfield, IL, 60015-4625, USA. mark_delegge@baxter.com.
authors.forename: Mark
authors.initials: M
authors.lastname: DeLegge
authors.affiliation: Baxter Healthcare SA Europe, CH-8010, Zürich, Switzerland. georg_kreymann@baxter.com.
authors.forename: Georg
authors.initials: G
authors.lastname: Kreymann
authors.affiliation: Department of Anesthesiology and Intensive Care Medicine, Karolinska University Hospital, Huddinge, Karolinska Institutet, 141 86, Stockholm, Sweden. jan.wernerman@karolinska.se.
authors.forename: Jan
authors.initials: J
authors.lastname: Wernerman
authors.affiliation: Center for Translational Research in Aging & Longevity, Department of Health & Kinesiology, Texas A&M University, 4243 Ireland St #336, College Station, TX, 77843, USA. RWolfe2@uams.edu.
authors.forename: Robert R
authors.initials: RR
authors.lastname: Wolfe
mesh_terms: D000596:Amino Acids / Q000008:administration & dosage*; D016638:Critical Illness; D004044:Dietary Proteins / Q000008:administration & dosage*; D006801:Humans; D018529:Nutritional Support / Q000379:methods*
chemical_list: D000596:Amino Acids; D004044:Dietary Proteins