CI: Initiation of Enteral Nutrition (2012)


Doig GS, Heighes PT, Simpson F, Sweetman EA. Early enteral nutrition reduces mortality in trauma patients requiring intensive care: A meta-analysis of randomised controlled trials. Injury. 2011 Jan; 42(1): 50-56.

PubMed ID: 20619408
Study Design:
Meta-analysis or Systematic Review
M - Click here for explanation of classification scheme.
Quality Rating:
Positive POSITIVE: See Quality Criteria Checklist below.
Research Purpose:

To determine whether early EN has benefits to critically ill adult trauma patients.

Inclusion Criteria:
  • Methodologically sound RCT that compared standard EN provided within 24 hours of injury to standard care
  • Subjects were critically ill adult trauma patients (eg, mechanically ventilated, multi-trauma with urgent laparotomy, appropriate illness severity score)
  • ICU stay more than two days.
Exclusion Criteria:
  • Major methodological flaws
  • Publication based on sub-groups of patients from larger published trials
  • Non-RCTs
    • Letters
    • Observational studies
    • Systematic reviews
    • Narrative reviews
    • Previous meta-analyses
  • No provision of primary comparison of timing of EN
  • Non-adult trauma population
  • Crossover trials
  • Pre-operative interventions
  • Failure to report mortality
  • Evaluation of specialty EN formula
  • Early EN not commenced within 24 hours.
Description of Study Protocol:

Search Plan 

MEDLINE and EMBASE were searched using appropriately broad medical subject heading and EMTREE terms for nutritional support and critical illness.


Meta-analysis of RCTs.


To be included in meta-analysis, studies had to incorporate standard EN within 24 hours of ICU admission.

Statistical Analysis

  • Fixed effects model with OR
  • Tests for heterogeneity
  • α=0.05 denoted statistical significance
  • α=0.05 to 0.10 indicated a trend toward significance.
Data Collection Summary:


  • Methodological quality appraisal
  • Included trial characteristics
  • Patient-oriented outcomes
  • Complications and major ICU infections.

Dependent Variables

  • Primary outcomes:
    • Hospital discharge mortality
    • ICU discharge mortality
  • Secondary outcomes:
    • Incidence of vomiting or aspiration
    • Incidence of pneumonia
    • Incidence of bacteremia
    • Incidence of sepsis
    • Incidence and severity of multiple organ dysfunction syndrome.


Early standard EN within 24 hours of ICU admission. 

Description of Actual Data Sample:


Summary of Articles Reviewed  
Number of articles identified and retrieved as potentially relevant 701
Number of articles reviewed for more detailed evaluation 525
Number and type of studies considered for meta-analysis 33
Number of articles that met all criteria for inclusion 4



Summary of Results:

 Key Findings

Variable Number of Studies Early EN (Less than 24 hours) Standard Care P-value
Mortality (deaths/total subjects) 3 1/65 6/61 0.04
Pneumonia 1 9/27 16/25 0.05
MODS incidence 1 12/17 13/19 0.82
MODS severity (organ failures) 1 2.5±0.7 3.1±0.8 0.057


Author Conclusion:

Small studies of low quality suggest that there is a positive correlation between reduction in ICU and hospital discharge mortality to the initiation of early standard enteral nutrition. A large multi-center trial should be conducted to support these findings.

Funding Source:
University/Hospital: Northern Clinical School, University of Sydney
Reviewer Comments:
Quality Criteria Checklist: Review Articles
Relevance Questions
  1. Will the answer if true, have a direct bearing on the health of patients? Yes
  2. Is the outcome or topic something that patients/clients/population groups would care about? Yes
  3. Is the problem addressed in the review one that is relevant to dietetics practice? Yes
  4. Will the information, if true, require a change in practice? Yes
Validity Questions
  1. Was the question for the review clearly focused and appropriate? Yes
  2. Was the search strategy used to locate relevant studies comprehensive? Were the databases searched and the search termsused described? Yes
  3. Were explicit methods used to select studies to include in the review? Were inclusion/exclusion criteria specified andappropriate? Wereselectionmethods unbiased? Yes
  4. Was there an appraisal of the quality and validity of studies included in the review? Were appraisal methodsspecified,appropriate, andreproducible? No
  5. Were specific treatments/interventions/exposures described? Were treatments similar enough to be combined? Yes
  6. Was the outcome of interest clearly indicated? Were other potential harms and benefits considered? Yes
  7. Were processes for data abstraction, synthesis, and analysis described? Were they applied consistently acrossstudies and groups? Was thereappropriate use of qualitative and/or quantitative synthesis? Was variation in findings among studies analyzed? Were heterogeneity issued considered? If data from studies were aggregated for meta-analysis, was the procedure described? Yes
  8. Are the results clearly presented in narrative and/or quantitative terms? If summary statistics are used, are levels ofsignificance and/or confidence intervals included? Yes
  9. Are conclusions supported by results with biases and limitations taken into consideration? Are limitations ofthe review identified anddiscussed? Yes
  10. Was bias due to the review's funding or sponsorship unlikely? Yes