CI: Immune-Modulating Enteral Nutrition (2006)

Study Design:
- Click here for explanation of classification scheme.
Quality Rating:
Research Purpose:
Evaluate a new immune-enhancing diet that includes Glutamine arginine, omega-3 polyunsaturated fatty acids, nucleotides, and branched chain amino acids in post injury patients.     
Inclusion Criteria:
  • Male and nonpregnant female trauma patients 18 to 65 years of age with a Injury Severity Score (ISS) of 16 to 45 or an Abdominal Trauma Index (ATI value of 18 to 40.
  • Patients had to receive their enteral diet for at least 72 hours.
Exclusion Criteria:
  • Head injury with a Glasgow Coma Scale (GCS) score <8 at 24hrous postinjury,
  • Pelvic fracture requiring >6 Units of blood within the first 12 hours
  •  24-hours transfusion requirement >20 Units of blood
  • Planned repeat laparotomy within 72 hours
  • Significant pre-existing disease including insulin-dependent Diabetes Mellitus, chronic obstructive pulmonary disease, congestive heart failure, or other complicated cardiac disease, hepatic dysfunction, renal failure, morbid obesity, metastatic cancer, HIV, organ transplantation, received immunosuppressive drugs, chemotherapy, or radiation.
Description of Study Protocol:
  • Patients were entered at five centers. Three centers started study recruitment in May 1991 and two centers were subsequently added.
  • Patients were randomized by a computer-generated schedule with equal probability of receiving early enteral feeding with the study diet or the control diet.
  • Patient either received study diet (Immun-Aid) or control diet (Vivonex T.E.N.).
  • Enteral feeding was started within 24 hours of injury.
  • Feeding was delivered by continuous pump infusion.
  • The study diet was started at full strength 25ml/h whereas the control diet was started at either full strength 25ml/h or half strength 50ml/h. 
  • Diets were advanced at set intervals to deliver the targeted total caloric goal of 35 kcal/kg/day by 72 hours.  


Statistical Analysis

  • Comparisons between treatment groups were performed by Wilcoxon ranksum test for continuous variables and Fisher's exact test for dichotomous categorical variables.
  • p value <0.05 is considered to be significant.


Data Collection Summary:

Outcome Variables:

  • Number of ventilator days
  • Length of hospital stay
  • Length of ICU stay
  • Abdominal Abscess
  • Multiple organ failure


Description of Actual Data Sample:

Initial N: 114

Attrition (final N): 98 ( 69 male, 29 female) (51 study group vs. 47 control group)

Age: 30 Study group vs.  31 Control group

Ethnicity: N/A



Summary of Results:



Study Group

Control group

Statistical Significance of Group Difference

Ventilator (Days)



Not Significant

ICU (Days)



Not Significant

Hospital (Days)   



Not Significant

Abdominal Abssess (%)



p = 0.02

Multiple Organ Failure (%)



         p = 0.02

Other Findings

There was no significant difference in mortality [study = 1 (2%) vs. control = 2 (4%)]

Author Conclusion:
  • Similar entry criteria and nutritional diagnosis of the control diet were used.
  • Author's found study diet to be safe.
  • The study group had significantly fewer intra-abdominal abscesses and significantly less multiple organ failure.
  • No significant difference in mortality.
  • The study group received more nitrogen.
Funding Source:
Government: CDC, Ministry of Health (Rwanda)
University/Hospital: University of California San Fransisco,
Reviewer Comments:

Small sample size.

Many patients excluded based on exclusion criteria.

Quality Criteria Checklist: Primary Research
Relevance Questions
  1. Would implementing the studied intervention or procedure (if found successful) result in improved outcomes for the patients/clients/population group? (Not Applicable for some epidemiological studies) ???
  2. Did the authors study an outcome (dependent variable) or topic that the patients/clients/population group would care about? Yes
  3. Is the focus of the intervention or procedure (independent variable) or topic of study a common issue of concern to dieteticspractice? Yes
  4. Is the intervention or procedure feasible? (NA for some epidemiological studies) Yes
Validity Questions
1. Was the research question clearly stated? Yes
  1.1. Was (were) the specific intervention(s) or procedure(s) [independent variable(s)] identified? Yes
  1.2. Was (were) the outcome(s) [dependent variable(s)] clearly indicated? Yes
  1.3. Were the target population and setting specified? Yes
2. Was the selection of study subjects/patients free from bias? ???
  2.1. Were inclusion/exclusion criteria specified (e.g., risk, point in disease progression, diagnostic or prognosis criteria), and with sufficient detail and without omitting criteria critical to the study? Yes
  2.2. Were criteria applied equally to all study groups? Yes
  2.3. Were health, demographics, and other characteristics of subjects described? Yes
  2.4. Were the subjects/patients a representative sample of the relevant population? ???
3. Were study groups comparable? Yes
  3.1. Was the method of assigning subjects/patients to groups described and unbiased? (Method of randomization identified if RCT) Yes
  3.2. Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline? Yes
  3.3. Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.) N/A
  3.4. If cohort study or cross-sectional study, were groups comparable on important confounding factors and/or were preexisting differences accounted for by using appropriate adjustments in statistical analysis? N/A
  3.5. If case control study, were potential confounding factors comparable for cases and controls? (If case series or trial with subjects serving as own control, this criterion is not applicable.) N/A
  3.6. If diagnostic test, was there an independent blind comparison with an appropriate reference standard (e.g., "gold standard")? Yes
4. Was method of handling withdrawals described? Yes
  4.1. Were follow-up methods described and the same for all groups? Yes
  4.2. Was the number, characteristics of withdrawals (i.e., dropouts, lost to follow up, attrition rate) and/or response rate (cross-sectional studies) described for each group? (Follow up goal for a strong study is 80%.) Yes
  4.3. Were all enrolled subjects/patients (in the original sample) accounted for? Yes
  4.4. Were reasons for withdrawals similar across groups? Yes
  4.5. If diagnostic test, was decision to perform reference test not dependent on results of test under study? Yes
5. Was blinding used to prevent introduction of bias? No
  5.1. In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate? No
  5.2. Were data collectors blinded for outcomes assessment? (If outcome is measured using an objective test, such as a lab value, this criterion is assumed to be met.) ???
  5.3. In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded? N/A
  5.4. In case control study, was case definition explicit and case ascertainment not influenced by exposure status? N/A
  5.5. In diagnostic study, were test results blinded to patient history and other test results? ???
6. Were intervention/therapeutic regimens/exposure factor or procedure and any comparison(s) described in detail? Were interveningfactors described? Yes
  6.1. In RCT or other intervention trial, were protocols described for all regimens studied? Yes
  6.2. In observational study, were interventions, study settings, and clinicians/provider described? N/A
  6.3. Was the intensity and duration of the intervention or exposure factor sufficient to produce a meaningful effect? ???
  6.4. Was the amount of exposure and, if relevant, subject/patient compliance measured? Yes
  6.5. Were co-interventions (e.g., ancillary treatments, other therapies) described? Yes
  6.6. Were extra or unplanned treatments described? N/A
  6.7. Was the information for 6.4, 6.5, and 6.6 assessed the same way for all groups? Yes
  6.8. In diagnostic study, were details of test administration and replication sufficient? Yes
7. Were outcomes clearly defined and the measurements valid and reliable? Yes
  7.1. Were primary and secondary endpoints described and relevant to the question? Yes
  7.2. Were nutrition measures appropriate to question and outcomes of concern? Yes
  7.3. Was the period of follow-up long enough for important outcome(s) to occur? ???
  7.4. Were the observations and measurements based on standard, valid, and reliable data collection instruments/tests/procedures? Yes
  7.5. Was the measurement of effect at an appropriate level of precision? Yes
  7.6. Were other factors accounted for (measured) that could affect outcomes? ???
  7.7. Were the measurements conducted consistently across groups? Yes
8. Was the statistical analysis appropriate for the study design and type of outcome indicators? Yes
  8.1. Were statistical analyses adequately described and the results reported appropriately? Yes
  8.2. Were correct statistical tests used and assumptions of test not violated? Yes
  8.3. Were statistics reported with levels of significance and/or confidence intervals? Yes
  8.4. Was "intent to treat" analysis of outcomes done (and as appropriate, was there an analysis of outcomes for those maximally exposed or a dose-response analysis)? No
  8.5. Were adequate adjustments made for effects of confounding factors that might have affected the outcomes (e.g., multivariate analyses)? ???
  8.6. Was clinical significance as well as statistical significance reported? No
  8.7. If negative findings, was a power calculation reported to address type 2 error? No
9. Are conclusions supported by results with biases and limitations taken into consideration? Yes
  9.1. Is there a discussion of findings? Yes
  9.2. Are biases and study limitations identified and discussed? Yes
10. Is bias due to study's funding or sponsorship unlikely? Yes
  10.1. Were sources of funding and investigators' affiliations described? Yes
  10.2. Was the study free from apparent conflict of interest? Yes