Theory supporting hypocaloric nutrition
The nutrition paradox
Nutrition may not prevent muscle breakdown
Autophagy may be a good thing in moderation.
Landmark papers about hypocaloric nutrition
ARDS-NET investigators. Initial trophic vs. full enteral feeding in patients with acute lung injury: the EDEN randomized trial. JAMA 2012.
Arabi YM et al. Permissive underfeeding or standard enteral feeding in critically ill Adults (the PERMIT trial), NEJM 2015.
Limitations of both EDEN and the PERMIT trial
Nuts & bolts of providing hypocaloric enteral nutrition
- 1 kCal/kg, low-protein (~0.04 grams/ml)
- Osmolite 1-cal
- Nutren 1.0
- 1 kCal/kg, high-protein (~0.065 grams/ml)
- Promote, Promote with fiber
- Replete, Replete with fiber
- Peptamen VHP
- 1.5 kCal/kg concentrated (~0.065 grams/ml)
- Isosource 1.5
- Nutren 1.5
- Peptamen 1.5
- Osmolite 1.5
- Jevity 1.5
- Respalor 1.5
- 2 kCal/kg concentrated (~0.08 grams/ml)
- TwoCal HN
- Nutren 2.0
- NutriRenal 2.0
- NovaSource Renal
- Nutrition has a variety of effects on the endocrine and immune systems. Clinical evidence is required to determine the ideal nutritional target during acute illness, rather than assuming that 100% nutritional provision is ideal all the time.
- The PERMIT trial provides evidence that hypocaloric nutrition is safe among most acutely ill ICU patients for limited periods of time (e.g. 50% calorie provision for two weeks with administration of 100% of protein requirements).
- Currently it is unclear whether hypocaloric or full nutrition is superior upon admission to the ICU. The ideal nutritional strategy likely varies between patients based on several variables (e.g. pre-existing malnutrition, difficulty tolerating feeds).
- Hypocaloric nutrition may be a reasonable short-term approach for many patients who are having difficulty tolerating 100% caloric administration.
- For most ICU patients (e.g. without morbid obesity or renal failure), the following table may be used to quickly estimate a prescription for enteral nutrition which provides 100% of estimated protein requirements despite varying levels of calories.
- Schetz M et al. Does artificial nutrition improve outcome of critical illness? Critical Care 2013.
- Wischmeyer PE. The evolution of nutrition in critical care: how much, how soon? Critical Care 2013.