How Much and What Type of Protein Should a Critically Ill Patient Receive?

Abstract

Protein loss, manifested as loss of muscle mass, is observed universally in all critically ill patients. Depletion of muscle mass is associated with impaired function and poor outcomes. In extreme cases, protein malnutrition is manifested by respiratory failure, lack of wound healing, and immune dysfunction. Protecting muscle loss focused initially on meeting energy requirements. The assumption was that protein was being used (through oxidation) as an energy source. In healthy individuals, small amounts of glucose (approximately 400 calories) protect muscle loss and decrease amino acid oxidation (protein-sparing effect of glucose). Despite expectations of the benefits, the high provision of energy (above basal energy requirements) through the delivery of nonprotein calories has failed to demonstrate a clear benefit at curtailing protein loss. The protein-sparing effect of glucose is not clearly observed during illness. Increasing protein delivery beyond the normal nutrition requirements (0.8 g/k/d) has been investigated as an alternative solution. Over a dozen observational studies in critically ill patients suggest that higher protein delivery is beneficial at protecting muscle mass and associated with improved outcomes (decrease in mortality). Not surprisingly, new Society of Critical Care Medicine/American Society for Parenteral and Enteral Nutrition guidelines and expert recommendations suggest higher protein delivery (>1.2 g/kg/d) for critically ill patients. This article provides an introduction to the concepts that delineate the basic principles of modern medical nutrition therapy as it relates to the goal of achieving an optimal management of protein metabolism during critical care illness, highlighting successes achieved so far but also placing significant challenges limiting our success in perspective.

DGEM-Leitlinie: „Klinische Ernährung in der Intensivmedizin“

“…Allerdings wird dieses Konzept bereits seit mehr als 30 Jahren kritisiert, da vermutlich der proportionale Bedarf an einzelnen Aminosäuren speziell in der Akutpphase nach schwerer Homöostasestörung nicht mit dem proportionalen Bedarf gesunder Individuen gleichzusetzen ist (genauso wenig, wie eine ausgeglichene Stickstoffbilanz mit einer optimalen Bedarfsdeckung für reparative oder immunologische Prozesse gleichzusetzen ist) [340]. Dabei kann die Zufuhr von disproportionalen Aminosäurenlösungen zusätzliche metabolische Belastungen erzeugen [341], diewie bereits für eine exzessive Glutaminzufuhr nachgewiesendurchaus klinisch relevant sein können [342]. Trotz dieser bis heute nicht für die restlichen Aminosäuren geklärten Problematik ist die Zufuhr von Aminosäurenlösungen im Rahmen einer parenteralen Ernährung aus oben genannten Gründen insbesondere dann erforderlich, wenn im Rahmen antikataboler Konzepte die endogene Bedarfsdeckung (und damit der Verlust an Muskeleiweiß) minimiert werden soll.…”

Status and nutritional therapy in elective and emergency neurosurgery patients

“…Similarly, the authors included patients in the ICU and infirmary who received enteral nutrition in the open system, whose process requires manipulation of the enteral formula, with packaging for administration in intermittent periods (21) . The energy deficit accumulated in the first week in the ICU is described as a strong predictor of clinical outcomes, and the delay to the start of ENT may expose the patients to the energy deficit, which probably will not be compensated during hospitalization (22) . Tsai and colleagues evaluated associations between calories and protein consumed in the first week of ICU admission and outcomes.…”

Peptide nutrient‐energy dense enteral feeding in critically ill infants: an observational study

“…Gastric fed infants had a mean (SD) GRV of 3.5 (2.9) mL kg À1 day À1 and post-pyloric fed infants a GRV of 5.4 (6.9) mL kg À1 day À1 . Feeding was withheld for perceived feeding intolerance in two infants (7%) on two occasions for 19.5 h. In PICU-2, medication for the management of diarrhoea was prescribed to four infants (14%) on a median (IQR) of 7 (3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14) occasions.…”