CI: Gastric vs. Small Bowel Feeding (2011)


Esparza J, Boivin MA, Hartshorne MF, Levy H. Equal aspiration rates in gastrically and transpylorically fed critically ill patients. Intens Care Med 2001; 27: 660-664.

PubMed ID: 11398691
Study Design:
Randomized Controlled Trial
A - Click here for explanation of classification scheme.
Quality Rating:
Neutral NEUTRAL: See Quality Criteria Checklist below.
Research Purpose:

To determine differences in aspiration rates between gastrically and transpylorically fed patients in the ICU.

Inclusion Criteria:

Not described except informed consent obtained

Exclusion Criteria:

Not described

Description of Study Protocol:


Not described


RCT; Randomization scheme not described.


Not used


  • 10 French feeding tube placed in either stomach (NG) or small bowel (NJ
  • EN with Perative formula initiated at 20mL per hour and advanced 20mL per four hours until reached goal feeding rate which was based on Harris-Benedict equation
  • Administer Tc-Su colloid added to enteral formula, fed Monday through Thursday, scanned Tuesday through Friday
  • Head of bed>30 degrees
  • Promotility agents if residual>150ml
  • Hold EN feeds four hours if residual>150ml.

Statistical Analysis

  • Power analysis projected a sample size of 54 needed to detect 30% absolute difference in aspiration rate with 80% power and α<0.05
  • Student’s T-test for continuous variables
  • Chi square test for dichotomous variables
  • Two-tailed P-value <0.05 considered to indicate statistically significant difference.
Data Collection Summary:

Timing and method of measurements  

  • Clinical aspiration (feed refluxed into patient’s mouth associated with either feed in pulmonary secretions–assessed visually (oxygen desaturation at least two percentage points)
  • Isotopic aspiration (pulmonary secretions collected into shielded bedside vacuum containers and scanned daily; aspiration determined to have occurred if 99mTc-tagged sulfur colloid tracer detected in secretions).

Dependent variables (outcomes) 


Independent Variables (intervention or procedure) 

NG or NJ enteral feeding

Description of Actual Data Sample:
  • Initial N: (percent male): 54
    • NG n=27 (63% male)
    • NJ n=27 (74% male)
  • Final N: (percent attrition): No attrition
  • Age: NS difference by group
    • NG 50±17
    • NJ 45±14
  • Ethnicity: Not described
  • Other relevant setting characteristics: MICU
  • Anthropometrics or other relevant subject characteristics: No significant differences by group
    • APACHE II scores (NG 17.1±5.9, NJ 15.8±4.0)
    • SAPS (NG 10.1±3.7, NJ 9.4±2.8)
    • Glasgow Coma Scale (NG 10±4, NJ 10±4)
    • Pneumonia (NG 6/27, NJ 5/27)
  • Location: University of New Mexico, Albuquerque, NM.
Summary of Results:

Other findings

Key finding

Transpyloric feeding not associated with lower incidence in critically ill patients

NG vs. NJ Feeding Tube Placement





Mean feeding days




Isotopic aspiration

2/27 (7%)

3/24 (13%)



11/27 (41%)

10/27 (37%)


Aspiration while on prokinetic agent for high GRV

0/52 patient feeding days

0/13 patient feeding days


 Other findings

  • Tip placement monitored daily with electromyographic electrode 4mm from tip; no tubes migrated from placement location
  • Patients followed during ICU stay for a maximum of eight days
  • No significant difference in average daily percent of goal fed with 64% and 67% for gastric and SB, respectively (P>0.05)
  • Nine patients suspected of clinical aspiration had negative scans of pulmonary secretions
  • Three of five patients who had isotopic aspiration also had clinical suspicion of aspiration (clinical suspicion sensitive to 60% of aspirations with 27% predictive value for aspiration  on 2/11 occasions).


Author Conclusion:

Transpyloric feeding is not associated with lower rate of aspiration in critically ill patients.

Funding Source:
Ross Products Division, Abbot Laboratories
Food Company:
Reviewer Comments:

Comments by reviewer from 2006:  

  • Others have calculated need for up to 300 patients to detect difference in aspiration of 20%. In spite of authors' comments, this one appears underpowered.
  • Important study since it evaluates the clinical observation of aspiration against isotopic aspiration.

Comment by 2011 reviewer:

  • This study rated as neutral because of validity criteria #2.1 and 2.2. As no inclusion/exclusion criteria were listed, reviewer not able to determine whether criteria were applied equally to both groups. Randomization method not described, but study groups were comparable per Table1.  



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? 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? No
  2.2. Were criteria applied equally to all study groups? ???
  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? Yes
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) No
  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.) Yes
  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? 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? 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? 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? Yes
  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? 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? 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? Yes
  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)? Yes
  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? Yes
  8.7. If negative findings, was a power calculation reported to address type 2 error? Yes
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