CI: Enteral Nutrition vs. Parenteral Nutrition (2012)

Study Design:
- Click here for explanation of classification scheme.
Quality Rating:
Research Purpose:
Review systematically and aggregate statistically the PRCTs conducted in patients appropriate for random assignment to Parenteral Nutrition (PN) and to compare the effects of PN with Enteral Nutrition (EN) and limited nutritional intervention on outcomes, which PN was provided at or above estimated energy needs.
Inclusion Criteria:
Only PRCTs that evaluated the effect of PN administrated at or above estimated energy needs compared with those of tube feeding or standard care on outcomes with clinical significance were reviewed.
Only subject specific information given: English speaking adults.
Exclusion Criteria:
Studies only evaluating nutritional outcomes
Description of Study Protocol:
MELINE search for PRCT evaluating effect of PN vs. EN or std care (IV dextrose and oral diet) from 1966 – 1999.  Ronald Koretx provided some studies from his files as well.
Study-quality scoring and subgroup analysis
  • quality scored based on concealed randomization, comparability of groups at baseline, endpoints (blinded to staff or not), well described treatment protocols, well-defined outcomes, and analysis by intent-to-treat.
  • Subgroup analysis based on 4 sources of heterogeneity: study-quality score, year of study publication, nutritional status of patients, and percentage of patient with cancer.
Analysis of PRCTs were divided into 2 categories: tube feeding compared with parenteral nutrition, and standard care compared with parenteral nutrition.
Data Collection Summary:
Infection, nutrition support complications, other complications, mortality.
Description of Actual Data Sample:
27 studies met criteria. Total of 1829 pts, EN = 985 and PN = 934.
Summary of Results:
Relative risks (RR) were calculated with intent-to-treat numbers.
Tube feeding compared to PN
  • 20 studies total of 508 tube feeding patients, and 525 PN patients)  EN was associated with significantly lower risk of infection (RR: 0.66); 95%CI: 0.56, 0.79).
  • Risk for nutrition support complications higher for EN than for PN (RR: 1.36; 95%CI: 0.96, 1.83) however this was positive for heterogeneity.
  • EN was associated with a lower risk of infection in all subgroup categories
  • Risk remained significantly lower for infections regardless of cancer, nutritional status, year of study publication, or study-quality score.
  • No difference in mortality.
Standard care compared with parenteral nutrition
  • 7 studies (387 pts received standard care and 409 patients received parenteral nutrition)
  • Significantly lower risk of infection (RR:0.77; 95% CI; 0.65, 0.91)  and a trend toward fewer other complications were found for those randomly assigned to standard care than those assigned to PN.  Test for heterogeneity was significant.
Author Conclusion:

EN and standard care associated with lower risk of infection than PN.

Authors admit their meta-analysis cannot "determine...whether aggressive enteral nutrition reduced the risk of infection or whether parenteral nutrition led to a higher risk of infection."

EN patients tend to receive less nutrition than PN because EN is often interrupted.

Failure to provide adequate nutrition to populations with protein-energy-malnutrition is associated with numerous consequences.

Authors concluded PN is associated with higher infection risks and should not be initiated in normally nourished patients unless good reason exists.

Authors recommend waiting 7 – 10 d before giving PN in normally nourished patient.

Funding Source:
University/Hospital: University of Michigan Medical Center
Reviewer Comments:

Noted limitations of each PRCT author used different definitions for the outcome variables evaluated.

This Analysis was comprehensive with significant findings supporting the use of enteral feedings or a diet has a lower risk of developing infections versus parenteral nutrition.

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? Yes
  5. Were specific treatments/interventions/exposures described? Were treatments similar enough to be combined? No
  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