CI: Enteral Nutrition vs. Parenteral Nutrition (2012)

Study Design:
- Click here for explanation of classification scheme.
Quality Rating:
Research Purpose:
Examine the effect of early ENT vs early parenteral feeding on septic complications in trauma patients in the first 15 days of hospitalization.
Inclusion Criteria:

Adults 18 years and older with intra-abdominal injury requiring laparotomy who sustained an ATI > 15. Intestinal repairs and anastomosis included

Exclusion Criteria:
Description of Study Protocol:

Jejunostomy feeding tubes were placed in all subjects. Then a randomization table determined which treatment group (EN or PN) within 8 hours post-op.  Vital HN was used as the enteral product.

Travasol, dextrose, and Intralipd was used as the  PN. Goal rate was to feed 1.5 – 2.0 g/kg/d of protein and 30 to 35 kcal/kg/d of calories.  

N2 bal calculated on day 1, 4, 7, 10 from a 24-hour urine collection. Septic morbidity included pneumonia, intra-abdominal abscess (IAA), empyema, or line sepsis during the first 15 days.  Authors defined each septic condition.

After discharge, charts were reviewed.

Data Collection Summary:

Amount of nutrition delivered, time from injury to institution of feeding, septic morbidity rates and clinical outcomes in a population of consecutive trauma pts w/ an ATI > 15.

Also measured; length of stay, ventilator days, tube feeding days, number of antibiotics and number of days on antibiotics, failure of enteral nutrition requiring cross over to TPN, number of units of blood administered in the first 24 hours and during total hospitalization

Description of Actual Data Sample:
96 trauma patients.
EN = 51
TPN = 45
(2 died from original 98 pts)
Summary of Results:

No significant difference between demographics and mechanism of injury.

No significant differences in blood requirements during the first 24 hours, total blood administered, days on a vent, number of antibiotics, or number of days on antibiotics. 

No significant differences in nitrogen balance between either group on any day.

EN patient received less nutrition per kg than did TPN (p <0.05).

EN patient had significantly less septic morbidity than PN pts.  EN patients sustained significantly fewer infections per patient that the TPN group (p <0.03)

Of patients with a high ISS (>20), 15% of EN patients developed an infection versus 52% of the TPN group (p<0.002).

When pneumonia, abscesses and /or line sepsis grouped together: 15.7% of EN pts & 40% PN pts experienced one of these complications (p<0.02).

In patients with an ATI > 24, the use of TPN was associated with a sevenfold increased in the risk of infection (p<0.05).

If you consider the presence of pneumonia, intra-abdominal abscess, or empyema as source of infection, EN was most beneficial in the most several injured pts: 3/20 (15%) EN & 8/12 (66.7%) PN, p<0.003.

11/51 EN pts developed diarrhea compared to 7/45 PN, p<0.01.

Author Conclusion:

Authors concluded EN pts experiences significantly less septic morbidity, including fewer infections per patient and significantly fewer infections per infected patient .

Route of nutrition appears to be more important than actual caloric needs being met.

EN may improve status of gut immune system, restores normal gut architecture and microflora, and aid mucosa in withstanding challenges to these systems.

Authors added, it is unclear if EN improves rate of septic morbidity or if TPN causes increased septic complications.

Funding Source:
University/Hospital: University of Tennessee
Reviewer Comments:

Poorly defined exclusion criteria.

Unable to blind treatment group to investigators.

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? No
  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? Yes
  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