Parenteral vs. enteral nutrition in the critically ill patient: a meta-analysis of trials using the intention to treat principle
- 2.7k Downloads
Controversy surrounds the use of parenteral nutrition in critical illness. Previous overviews used composite scales to identify high-quality trials, which may mask important differences in true methodological quality. Using a component-based approach this meta-analysis investigated the effect of trial quality on overall conclusions reached when standard enteral nutrition is compared to standard parenteral nutrition in critically ill patients.
An extensive literature search was undertaken to identify all eligible trials. We retrieved 465 publications, and 11 qualified for inclusion. Nine trials presented complete follow-up, allowing the conduct of an intention to treat analysis.
Aggregation revealed a mortality benefit in favour of parenteral nutrition, with no heterogeneity. A priori specified subgroup analysis demonstrated the presence of a potentially important treatment-subgroup interaction between studies of parenteral vs. early enteral nutrition compared to parenteral vs. late enteral. Six trials with complete follow-up reported infectious complications. Infectious complications were increased with parenteral use. The I 2 measure of heterogeneity was 37.7%.
Intention to treat trials demonstrated reduced mortality associated with parenteral nutrition use. A priori subgroup analysis attributed this reduction to trials comparing parenteral to delayed enteral nutrition. Despite an association with increased infectious complications, a grade B+ evidence-based recommendation (level II trials, no heterogeneity) can be generated for parenteral nutrition use in patients in whom enteral nutrition cannot be initiated within 24 h of ICU admission or injury.
KeywordsEnteral nutrition Parenteral nutrition Meta-analysis Randomised controlled trials Critical illness Critical appraisal
This work was supported in part by grants from the Australian and New Zealand Intensive Care Foundation and the NorthCare Foundation.
- 6.Preiser JC, Berre J, Carpentier Y, Jolliet P, Pichard C, Van Gossum A, Vincent JL (1999) Management of nutrition in European intensive care units: results of a questionnaire. Working Group on Metabolism and Nutrition of the European Society of Intensive Care Medicine. Intensive Care Med 25:95–101CrossRefPubMedGoogle Scholar
- 7.Martin CM, Doig GS, Heyland DK, Morrison T, Sibbald WJ (2004) Multicentre, cluster-randomized clinical trial of algorithms for critical-care enteral and parenteral therapy (ACCEPT). Can Med Assoc J 170:197–204Google Scholar
- 14.Egger M, Juni P, Bartlett C, Holenstein F, Sterne J (2003) How important are comprehensive literature searches and the assessment of trial quality in systematic reviews? Empirical study. Health Technol Assess 7:1–76Google Scholar
- 19.Jadad AR, Moore RA, Carroll D, Jenkinson C, Reynolds DJ, Gavaghan DJ, McQuay HJ (1996) Assessing the quality of reports of randomized clinical trials: is blinding necessary? Control Clin Trials 17:1–12Google Scholar
- 25.Doig GS, Simpson F, Delaney A (2004) A review of the true methodological quality of nutritional support trials conducted in the critically ill: time for improvement. Anesth Analg (in press)Google Scholar
- 31.Kleinbaum DG, Kupper LL, Morgenstern H (1982) Measures of disease frequency: incidence. In: Kleinbaum DG, Kupper LL, Morgenstern H (eds) Epidemiological research: principles and quantitative methods. Van Nostrand Reinhold, New York, pp 96–115Google Scholar
- 35.Brookes ST, Whitley E, Peters TJ, Mulheran PA, Egger M, Davey SG (2001) Subgroup analyses in randomised controlled trials: quantifying the risks of false-positives and false-negatives. Health Technol Assess 5:1–56Google Scholar
- 41.Braga M, Vignali A, Gianotti L, Cestari A, Profili M, Di C, V (1996) Immune and nutritional effects of early enteral nutrition after major abdominal operations. Eur J Surgery 162:105–112Google Scholar
- 44.Wischmeyer PE, Lynch J, Liedel J, Wolfson R, Riehm J, Gottlieb L, Kahana M (2001) Glutamine administration reduces Gram-negative bacteremia in severely burned patients: a prospective, randomized, double-blind trial versus isonitrogenous control. Crit Care Med 29:2075–2080CrossRefPubMedGoogle Scholar
- 52.Woodcock NP, Zeigler D, Palmer MD, Buckley P, Mitchell CJ, MacFie J (2001) Enteral versus parenteral nutrition: a pragmatic study. Nutrition 17:1–12Google Scholar
- 53.Gianotti L, Braga M, Vignali A, Balzano G, Zerbi A, Bisagni P, Di C, V, Fischer JE, Rombeau J, Harrington D (1997) Effect of route of delivery and formulation of postoperative nutritional support in patients undergoing major operations for malignant neoplasms. Arch Surg 132:1222–1230PubMedGoogle Scholar
- 66.Dellinger RP, Zimmerman JL, Taylor RW, Straube RC, Hauser DL, Criner GJ, Davis K Jr, Hyers TM, Papadakos P (1998) Effects of inhaled nitric oxide in patients with acute respiratory distress syndrome: results of a randomized phase II trial. Inhaled Nitric Oxide in ARDS Study Group. Crit Care Med 26:15–23CrossRefPubMedGoogle Scholar
- 68.Cook DJ (1995) Clinical trials in the treatment of sepsis: an evidence-based approach. In: Sibbald WJ, Vincent JL (eds) Clinical trials for the treatment of sepsis. Springer, Berlin Heidelberg New York, pp XIX–XXXIGoogle Scholar
- 69.Drummond MF, Stoddart GL, Torrance GW (1995) Cost-effectiveness analysis In: Drummond MF, Stoddart GL, Torrance GW (eds) Methods for the economic evaluation of health care programmes. Oxford University Press, New York, pp 74–112Google Scholar