CI: Enteral Nutrition Energy Delivery (2012)

Study Design:
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Quality Rating:
Research Purpose:
To determine the effect of initiating early enteral nutrition on neurological outcome, infection, and total complications in a population of head-injured patients.
Inclusion Criteria:
  1. Presence of head injury necessitating mechanical ventilation from day one.
  2. Best Glasgow Coma Scale (GCS) score of greater than 3.
  3. At least one reactive pupil during the first 24-hour period.
  4. Greater than 10 years of age.
  5. Inability to receive oral nutrition for more than 24 hours.
  6. Must be able to tolerate the initiation of enteral nutrition within 24 hours of injury.
Exclusion Criteria:
  1. Recruitment into a concurrent drug study.
  2. Gunshot head wounds.
  3. Presence of organ failure or potentially fatal disease pre-head injury.
  4. Moribund state immediately post-head injury.
  5. Difficulty obtaining follow-up.
Description of Study Protocol:

Used a balanced six-block sequence generated from a randomized number table, in a 1:1 ratio, to assign subjects to the control or intervention group.

Enteral nutrition was started from day 1 in both groups and increased to meet estimated requirements.

Control patients received EN via orogastric or nasogastric tubes starting at 15 mL/hr and ­as tolerated up to the goal rate in 30 mL increments. Feeding was stopped from 12:00pm to 6:00am.  Feeding rate was increased if residuals were <50 mL on two consecutive occasions.  Feeding rates were held the same if residuals were between 50-150 mL, and rate was reduced by 50% if residuals exceeded 150 mL.

Intervention patients received EN via intestinal feeding (or gastric feeding when intestinal feeding was contraindicated) and were started at a feed rate that would meet their full estimated needs from day 1. The threshold for tolerance of feeding was established as = 200 mL.

Data Collection Summary:

Serum concentrations of albumin, prealbumin, IGF-1, C-reactive protein, pupillary response, Injury Severity Score, and Glasgow Coma Scale.

Outcome(s) and other measures:

  1. Death
  2. Length of Hospital Stay
  3. Infection
  4. Drug Cost
Description of Actual Data Sample:
82 total patients participated in the study.
  • 41 standard EN
  • 41 enhanced EN (Enhanced = feeding rate initiated at goal starting from day 1).
Summary of Results:

Infective Complications:

  • Fewer intervention patients suffered infective complications (p = .02)
  • Fewer intervention patients suffered from more than one total complication (p= .046)
  • Trend toward fewer infective complications occurred in intervention vs. control patients with moderate (75% vs 48% p = .18) and severe injuries (92% vs. 75% p = .21)

Length of Hospital Stay:

  • Intervention patients achieved discharge more quickly (median days to discharge, 30 [intervention] vs. 46 [control], p = .008)


  • The cost of delivering EN was slightly higher in intervention patients because of the cost of nasointestinal tubes, but no overall cost increase was observed when intravenous fluids and drugs were taken into account.
  • At six-months post-injury, no difference in the mortality occurred (13% total population: intervention, 5; control, 6).
  • No difference in time until death was also seen at 6-months post-injury (median days: intervention, 10; control, 8.5).
Author Conclusion:

Enhanced EN appears to expedite recovery; however, it does not appear to alter mortality.

Early EN may reduce the number of patients suffering from infectious complications, as well as reduce the total number of complications suffered by each patient.

Improved outcomes appear more often in severely injured patients, except for infective complications, which appear to be improved in moderately injured patients.

Improved outcomes resulted without increasing treatment costs.

Funding Source:
Reviewer Comments:
Very detailed trial with well-established inclusion/exclusion criteria. Although method of randomization was described in detail, allocation concealment was not fully disclosed
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) Yes
  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? N/A
  1.2. Was (were) the outcome(s) [dependent variable(s)] clearly indicated? N/A
  1.3. Were the target population and setting specified? N/A
2. Was the selection of study subjects/patients free from bias? Yes
  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? N/A
  2.2. Were criteria applied equally to all study groups? N/A
  2.3. Were health, demographics, and other characteristics of subjects described? N/A
  2.4. Were the subjects/patients a representative sample of the relevant population? N/A
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) N/A
  3.2. Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline? N/A
  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")? N/A
4. Was method of handling withdrawals described? Yes
  4.1. Were follow-up methods described and the same for all groups? N/A
  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%.) N/A
  4.3. Were all enrolled subjects/patients (in the original sample) accounted for? N/A
  4.4. Were reasons for withdrawals similar across groups? N/A
  4.5. If diagnostic test, was decision to perform reference test not dependent on results of test under study? N/A
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? N/A
  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.) N/A
  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? N/A
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? N/A
  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? N/A
  6.4. Was the amount of exposure and, if relevant, subject/patient compliance measured? N/A
  6.5. Were co-interventions (e.g., ancillary treatments, other therapies) described? N/A
  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? N/A
  6.8. In diagnostic study, were details of test administration and replication sufficient? N/A
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? N/A
  7.2. Were nutrition measures appropriate to question and outcomes of concern? N/A
  7.3. Was the period of follow-up long enough for important outcome(s) to occur? N/A
  7.4. Were the observations and measurements based on standard, valid, and reliable data collection instruments/tests/procedures? N/A
  7.5. Was the measurement of effect at an appropriate level of precision? N/A
  7.6. Were other factors accounted for (measured) that could affect outcomes? N/A
  7.7. Were the measurements conducted consistently across groups? N/A
8. Was the statistical analysis appropriate for the study design and type of outcome indicators? No
  8.1. Were statistical analyses adequately described and the results reported appropriately? N/A
  8.2. Were correct statistical tests used and assumptions of test not violated? N/A
  8.3. Were statistics reported with levels of significance and/or confidence intervals? N/A
  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)? N/A
  8.5. Were adequate adjustments made for effects of confounding factors that might have affected the outcomes (e.g., multivariate analyses)? N/A
  8.6. Was clinical significance as well as statistical significance reported? N/A
  8.7. If negative findings, was a power calculation reported to address type 2 error? N/A
9. Are conclusions supported by results with biases and limitations taken into consideration? Yes
  9.1. Is there a discussion of findings? N/A
  9.2. Are biases and study limitations identified and discussed? N/A
10. Is bias due to study's funding or sponsorship unlikely? Yes
  10.1. Were sources of funding and investigators' affiliations described? N/A
  10.2. Was the study free from apparent conflict of interest? N/A