Critically evaluate the role of “immunonutrition” in the management of the critically ill patient.
Critically evaluate implies evaluation (including risk/benefit assessment) is required rather than just providing a list of constituents. Immunonutrition usually refers to enteral feeding formulae that have been enriched with a variety of pharmaconutrients. These include arginine, glutamine, omega-3 fatty acids, nucleotides, or a combination (eg. in commercial products such as Alitraq and Impact). Multiple randomised studies involving thousands of patients, and more recently meta-analyses have been performed. Studies have been heterogeneous with regard to patient groups and nutritional limbs, and results have been variable with regard to specific outcomes (eg. infectious complications and mortality). Some consistent benefits appear to be observed (eg. decreased infectious complications, or length of hospital stay) but are contradicted in other studies. Given the increased cost, the lack of consistent benefit, and the potential for harm, the overall role in the critically ill is still to be established. Recent literature includes:
· Montejo JC et al. Immunonutrition in the intensive care unit. A systematic review and consensus statement. Clin Nutr. 2003 Jun;22(3):221-33.
· Bertolini G et al. Early enteral immunonutrition in patients with severe sepsis: results of an interim analysis of a randomized multicentre clinical trial. Intensive Care Med. 2003
· Heyland DK, Novak F, Drover JW, Jain M, Su X, Suchner U. Should immunonutrition become routine in critically ill patients? A systematic review of the evidence. JAMA. 2001 Aug 22-
The wacky topic of immunonutrition is discussed in greater detail elsewhere.
The three papers cited by the college answer are somewhat dated:
Montejo, Juan C., et al. "Immunonutrition in the intensive care unit. A systematic review and consensus statement." Clinical Nutrition 22.3 (2003): 221-233.
Bertolini, Guido, et al. "Early enteral immunonutrition in patients with severe sepsis." Intensive care medicine 29.5 (2003): 834-840.
Heyland, Daren K., et al. "Should immunonutrition become routine in critically ill patients?: A systematic review of the evidence." Jama 286.8 (2001): 944-953.
There is more recent data:
Marik, Paul E., and Gary P. Zaloga. "Immunonutrition in High-Risk surgical patients a systematic review and analysis of the literature." Journal of Parenteral and Enteral Nutrition 34.4 (2010): 378-386.
Hübner, Ma, et al. "Preoperative immunonutrition in patients at nutritional risk: results of a double-blinded randomized clinical trial." European journal of clinical nutrition 66.7 (2012): 850-855.
Cerantola, Y., et al. "Immunonutrition in gastrointestinal surgery." British Journal of Surgery 98.1 (2011): 37-48.
Marik, Paul E., and Gary P. Zaloga. "Immunonutrition in critically ill patients: a systematic review and analysis of the literature." Intensive care medicine 34.11 (2008): 1980-1990.
Heyland, Daren, et al. "A randomized trial of glutamine and antioxidants in critically ill patients." New England Journal of Medicine 368.16 (2013): 1489-1497.