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Early enteral nutrition, provided within 24 h of injury or intensive care unit admission, significantly reduces mortality in critically ill patients: a meta-analysis of randomised controlled trials



To determine whether the provision of early standard enteral nutrition (EN) confers treatment benefits to critically ill patients.


Medline and EMBASE were searched. Hand citation review of retrieved guidelines and systematic reviews were undertaken, and academic and industry experts were contacted.

Methodologically sound randomised controlled trials (RCTs) conducted in critically ill patient populations that compared the delivery of standard EN, provided within 24 h of intensive care unit (ICU) admission or injury, to standard care were included.

The primary analysis was conducted on clinically meaningful patient-oriented outcomes. Secondary analyses considered vomiting/regurgitation, pneumonia, bacteraemia, sepsis and multiple organ dysfunction syndrome. Meta-analyses were conducted using the odds ratio (OR) metric and a fixed effects model. The impact of heterogeneity was assessed using the I 2 metric.


Six RCTs with 234 participants were analysed. The provision of early EN was associated with a significant reduction in mortality [OR = 0.34, 95% confidence interval (CI) 0.14–0.85] and pneumonia (OR = 0.31, 95% CI 0.12–0.78). There were no other significant differences in outcomes. A sensitivity analysis and a simulation exercise confirmed the presence of a mortality reduction.


Although the detection of a statistically significant reduction in mortality is promising, overall trial quality was low, trial size was small, and the findings may be restricted to the patient groups enrolled into included trials. The results of this meta-analysis should be confirmed by the conduct of a large multi-centre trial enrolling diverse critically ill patient groups.

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The conduct of this study was not funded. Ethics approval was not required to conduct this integrative meta-epidemiological study.

Conflict of interest statement

GSD has received academic research grants from Fresenius Kabi Deutschland GmbH and Baxter Healthcare Pty Ltd., and speaker's honoraria from Baxter Healthcare Pty Ltd. FS has received academic research grants from Fresenius Kabi Deutschland GmbH and Baxter Healthcare Pty Ltd., and speakers honoraria from Pharmatel-Fesenius Kabi Pty Ltd. EAS has received an academic research grant from Baxter Healthcare Pty Ltd. ARD has received an academic research grant from Cook Medical. PTH declares no competing interests.

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Correspondence to Gordon S. Doig.

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Doig, G.S., Heighes, P.T., Simpson, F. et al. Early enteral nutrition, provided within 24 h of injury or intensive care unit admission, significantly reduces mortality in critically ill patients: a meta-analysis of randomised controlled trials. Intensive Care Med 35, 2018–2027 (2009).

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  • Early enteral nutrition
  • Critical illness
  • Intensive care unit
  • Meta-analysis
  • Systematic review