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CI: Gastric vs. Small Bowel Feeding Tube Placement (2006)

Citation:

Heyland DK, Drover JW, MacDonald S, et al. Effect of postpyloric feeding on gastroesophageal regurgitation and pulmonary microaspiration: Results of a randomized controlled trial. Crit Care Med 2001; 29 (8): 1,495-1,501.

PubMed ID: 11505114
 
Study Design:
Randomized Controlled Trial
Class:
A - Click here for explanation of classification scheme.
Quality Rating:
Positive POSITIVE: See Quality Criteria Checklist below.
Research Purpose:

To determine the extent to which postpyloric feeding reduces gastroesophageal reflux (GER) and pulmonary microaspiration.

Inclusion Criteria:
  • Expected >72 hours stay in ICU
  • Eligible for EN feeding.
Exclusion Criteria:
  • GI bleed
  • Less than one week s/p esophageal, gastric, small bowel surgery
  • Surgical gastric or jejunal tube in place
  • Refusal.
Description of Study Protocol:

Recruitment 

Admission to ICU, met inclusion criteria and gave consent

Design

RCT; block randomization with sealed, opaque envelopes

Blinding

Not Applicable

Intervention

Gastric or postpyloric feeding tube placement [technesium-sulfur colloid (IV contrast) added to enteral formula, quantitative measurement of contrast aspirated by Xray].

Statistical Analysis: 
  • Pilot study
  • Interim analysis after 20 patients revealed over 200 patients needed to detect statistically significant difference in gastroesophageal reflux and aspiration
  • Multiple logistic regression model to compare rates of gastroesophageal reflux and aspiration between gastric and small bowel group
  • Analyzed data using log of radioactive cpm per specimen
  • Repeated measures analysis of variance (ANOVA) applied to two groups
  • Adjusted (least squared) means log of radioactive cpm per specimen derived from ANOVA and compared statistically using 5% significance level
  • Repeated measures ANOVA to compare gastric pH between two groups.
Data Collection Summary:

Timing and method of measurements  

  • All patients received radiolabeled EN feeds and advanced per protocol
  • Measured GRV every four hours
  • Oropharynx and endotracheal tube suctioned at baseline (time zero) and 60, 120, 240, 300 and 360 minutes after initiation of radiolabeled feeds (to detect regurgitation and aspiration)
  • Aspirates of gastric contents collected at time zero, 60, 120, 240, 300 and 360 minutes after initiation of radiolabeled feeds (to detect duodenogastric reflux).

Dependent variables (outcomes) 

  • Gastroesophageal regurgitation
  • Pulmonary aspiration. 
Independent Variables (intervention or procedure) 

Gastric or post-pyloric feeding tube tip placement

Description of Actual Data Sample:
  • Initial n (percent male): 39
    • Gastric =21 (66% male)
    • Postpyloric=12 (42% male)
  • Final n (percent attrition): No attrition
  • Age: 59.5±16.8 years
    • Gastric
    • Postpyloric 
  • Ethnicity: Not described
  • Other relevant setting characteristics: Medical/surgical ICU
  • Anthropometrics or other relevant subject characteristics: Mean APACHE II score 22.5±7.8
  • Location: Ontario, Canada.
Summary of Results:
  • 88% had microaspiration, with no difference by tube position
  • Patients fed into the stomach had more episodes of gastroesophageal regurgitation (39.8% vs. 24.9%, P=0.004)
  • Patients with gastroesophageal regurgitation more likely to aspirate (OR 3.2, 95% CI, 1.37, 7.77, P=0.09).
Author Conclusion:

Postpyloric feeding reduces GER and trends towards reduced aspiration.

Funding Source:
University/Hospital: Kingston General Hospital, Ontario, Canada
Reviewer Comments:
  • No power analysis was reported, however others have calculated need for up to 300 points to detect difference in aspiration of 20%
  • Study must lack power to detect aspiration
  • Important study since it uses very tight measure of microaspiration, since it clearly associates GER with aspiration (even though underpowered for the latter).
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? 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? 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? 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) 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.) 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? 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.) Yes
  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? Yes
  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? 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? 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? Yes
  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? N/A
  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? No
  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