Review ArticleImmunonutrition in the intensive care unit. A systematic review and consensus statement
Introduction
Enteral nutrition is the preferred method for feeding critically ill patients with functioning gastrointestinal tract. Enteral nutrition improves several clinical outcomes like infectious complications and ICU or hospital length of stay. Indeed, enteral nutrition seems to play a role in the modulation of the immune system of critically ill patients. Several specific substrates with immunological effects have been added, alone or in combination, to standard diets trying to modify the immune response of the patients. The number of these key nutrients, also called nutraceuticals or pharmaconutrients, is now increasing but arginine, glutamine, nucleotides and omega-3 polyunsaturated fatty acids seems to play a primordial role in the regulation of immunological and inflammatory responses in critically ill patients (1).
Enteral diets enriched with pharmaconutrients have been also called immune-enhancing diets. These immunonutrition formulas have been used in several studies trying to demonstrate their beneficial effects on laboratory, immunological and clinical parameters in comparison with standard diets in critically ill patients. However, results of these trials are controversial due to methodological limitations and to the heterogeneity of the studied patient populations. In order to advance in the knowledge in this field, the evidence-based medicine methodology has been also applied. Two meta-analysis 2., 3. have been recently published and both concluded that immunonutrition in critically ill patients could improve the incidence of nosocomial infections and shorten the length of stay, but do not improve mortality. This conclusion is also supported in another systematic review (4) but these authors also suggests that the effects of the immune-enhancing diets can be different depending on the subset of patients analyzed or on the methodological quality of the studies included in the meta-analysis.
The purpose of this study was to answer the following question: Compared to enteral nutrition with standard diets, has the use of diets enriched with pharmaconutrients a significant effect on the outcome of critically ill patients? In order to develop a process with clinical-practice implications we decided to use a combined methodology. A methodological group performed a systematic review. After this, a group of clinicians with experience in the field of nutritional support in critically ill patients discussed the appreciated results in order to obtain a consensus about the relevance of the result for the clinical practice and, finally, establish clinical recommendations about the use of pharmaconutrition in critically ill patients.
Section snippets
Working group configuration
Two separated working groups were created. A methodological group was formed with experts from the Ibero-American Cochrane Center. A clinical group was created with members of the Nutritional and Metabolic Working Group of the Spanish Society of Intensive Care Medicine and Coronary Units, clinicians with a large experience in the field of nutritional support of critically ill patients, asked by one of the authors (JCM, study coordinator) to participate in the project.
Parts of the study
The study was designed in a
Study identification and selection
Search strategy retrieved a number of 684 references. Finally, we reviewed 35 randomized studies. Seven of them 10., 11., 12., 13., 14., 15., 16. were papers with secondary data coming from one original study (Table 2). Data from these studies were similar to those provided by the primary published study. Another two studies were excluded 17., 18. because results from the control and the study groups were not clearly identified.
Twenty-six studies met the inclusion and exclusion criteria and
Discussion
Clinical guidelines are systematically developed statements designed to provide the best evidence to support the management strategies for patients with specific conditions. This paper represents the work of an independent group of experts trying to find the best evidence about the use of immune-enhancing diets in critically ill patients using the method of consensus (45). The methodology included a systematic review of the published trials (46) done by a group of epidemiologists and the
Acknowledgements
The authors thank Mireia Morera and Xavi Planet, from Novartis Consumer Health, for their assistance in making this study possible. The study was partially supported by a grant from Novartis Consumer Health (Barcelona, Spain).
References (54)
- Schloerb P R. Immune-enhancing diets: products, components and their rationales. J Parenter Enteral Nutr 2001; 25 (2...
- Beale R J, Bryg D J, Bihari D J. Immunonutrition in the critically ill: a systematic review of clinical outcome. Crit...
- Heys S D, Walker L G, Smith I, Eremin O I. Enteral nutritional supplementation with key nutrients in patients with...
- Heyland D K, Novak F, Drover J W, Jain M, Su X, Suchner U. Should immunonutrition become routine in critically ill...
- Moher D, Jadad A R, Nichol G, Penman M, Tugwell T, Walsh S. Assessing the quality of randomized controlled trials: an...
- Egger M, Smith G D. Bias in location and selection of studies. BMJ 1998; 316:...
- Sackett D L. Rules of evidence and clinical recommendations on the use of antithrombotic agents. Chest 1989; 95 (2...
- US Preventive Task Force. Guide to Clinical Preventive Services: An Assessment of the Effectiveness of 169...
- Canadian Task Force on the periodic Health Examination. The periodic health examination. Can Med Assoc J 1979; 121:...
- Bastian L, Weimann A, Regel G, Tscherne H. [Is modification of systemic inflammatory response syndrome and multiple...
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