CI: Enteral Nutrition vs. Parenteral Nutrition (2012)

Study Design:
- Click here for explanation of classification scheme.
Quality Rating:
Research Purpose:
To define the indications for and evaluate the cost-effectiveness of nutritional support in patients with acute pancreatitis.
Inclusion Criteria:
  • For the first 12 months, the study included all participants admitted to the hospital with a diagnosis of acute pancreatitis
  • For the next three months, data collection was limited to patients having acute pancreatitis and in need of nutritional support
  • Eligible patients were defined as:
    • Acute abdominal pain
    • Three-fold elecation of serum pancreatic enzymes amylase and lipase
    • Primary diagnosis of acute pancreatitis.
Exclusion Criteria:
  • Diagnosis other than acute pancreatitis
  • In the final three months, not requiring nutritional support.
Description of Study Protocol:
  • Patients admitted to facility during 12-month period and met criteria were entered into the study. The study was extended for three additional months to enroll more patients requiring nutritional support.
  • Patients kept nil per os (NPO) and given intravenous fluids and electrolytes for first 48 hours. Those with alcoholic etiology were given 5% glucose with multivitamin (folic acid and thiamin). Patients with improvement in 48 hours (signs, symptoms, serum enzyme levels) were given a soft oral diet. Good tolerance was advanced to regular diet. Those without improvement were graded by Ranson’s criteria to gauge severity and prognosis of disease and then randomized to TPN and bowel rest (PN) or jejunal elemental feeding (EN). Goal feeding rates were to provide 1.5g protein per kg per day and 25 to 30kcal per kg per day.
  • Patients receiving tube feedings were evaluated for tube tolerance, high residual volumes, exacerbation of abdominal pain and diarrhea. Blood sugar fluctuations were controlled with insulin injections and then by adding insulin to TPN. Weaning from nutritional support occurred when abdominal pain and distention settled and enzyme elevations had moved toward normal. Patients were reintroduced with oral liquids and advanced to soft, then solid oral diet.
Data Collection Summary:
Length of hospitalization (LOS) and duration of interventional feeding were used to determine the efficacy of management. Incidence of nutrition-related complications, tolerance of feeding and cost-effectiveness were also evaluated.
Description of Actual Data Sample:

156 patients entered the study:

  • 117 received no nutrition support (Group O)
  • 26 were randomized to EN
  • 27 were randomized to TPN.
Summary of Results:
  • Average length of stay (LOS) was eight days
    • Average LOS for Group O was four days
    • Average EN LOS was 14 days vs. TPN LOS was 18 days (P=0.1)
  • Feeding duration avg was 6.7 days for EN vs. 10.8 days for PN (P=0.03)
  • EN Patients received less than 50% of nutrient needs vs. PN received 85% (P<0.005)
  • 80% of EN tolerated oral diet advance vs. 63% of PN
  • No significant difference between disease severity
  • Nutrition-associated complications were more common in PN patients: Increased incidence of hyperglycemia, septic complications
  • Incidence of respiratory distress, multisystem organ failure, pancreatic necrosis, pseudocysts and death were similar in both groups
  • Average cost of $11,183 for hospitalization, because acute pancreatitis per patient
    • $23.30 per day for EN vs. $222 per day for PN
    • Proportion of hospital costs were 1.8% for EN vs. 8.4% for PN (P<0.0001).
Author Conclusion:
  • Most patients with acute pancreatitis do not need nutritional support and are able to resume oral feeding in two days
  • For those with severe disease, EN with an elemental diet was shown to be safer, less expensive and had a shorter LOS than did PN.
Funding Source:
University/Hospital: Medical College of Virginia Hospitals
Foundation associated with industry:
Reviewer Comments:
  • The study design was appropriate and provided sufficient statistical analysis
  • Didn't specify method of randomization.
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) ???
  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? Yes
  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.) No
  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? 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? 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? 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)? Yes
  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? N/A
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