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Does early enteral feeding after gastrointestinal surgery alter outcomes?

 

Feeding patients by the enteral route within 24 hours of gastrointestinal surgery is safe and well tolerated. Patients who were fed early had fewer infections and a shorter length of hospital stay. There is little evidence that keeping these patients nil by mouth is of any value.

 

Level of evidence: 1- (Meta-analysis with a high risk of bias)

 

Citation/s: Lewis SJ, Egger M, Sylvester PA, Thomas S. Early enteral feeding versus 'nil by mouth' after gastrointestinal surgery: systematic review and meta-analysis of controlled trials. BMJ 2001; 323: 773-776
 

Lead author's name and email: SJ Lewis: sjl@doctors.org

 

Three-part Clinical Question: Does a period of starvation after elective gastrointestinal surgery reduce wound dehiscence, septic complications, length of hospital stay and mortality?

Search Terms: Medline search: early enteral feeding, gastro-intestinal surgery

 

The Review:
 

Data Sources: Cochrane Library, Medline, Embase, Citation Index.

 

Study Selection: Randomised controlled trials published in English language journals were selected. Thirteen were identified and 2 excluded because they did not give outcomes data.
 

Data Extraction: Patients were elective GI surgery patients randomly allocated to receive either enteral feeding within 24 hours of surgery or nil by mouth plus IV fluids with introduction of enteral fluids and diet as tolerated. In 6 trials patients were fed directly into the small bowel and in 5 oral feed was given. Outcome data were given on anastomotic dehiscence, wound infection, pneumonias, other infections, intra-abdominal abscesses, vomiting, length of hospital stay and death. The types of feeds differed between trials and one trial used immunonutrition.
It is not possible to tell if the studies were multiple independent reviews of individual reports. They were tested for heterogeneity.

This meta-analysis is similar to Marik's in that the studies contained different patient populations, different feeding regimes and different routes of feeding. The trials are homogeneous in their conclusions regarding infection and length of stay despite being heterogeneous in clinical terms. This meta-analysis does not address the question of early enteral feeding after emergency gastrointestinal surgery

 

The Evidence:

 

Outcome

Time to Outcome

Typical CER

Typical OR

RRR

NNT

p Value

Anastomotic dehiscence

To hospital discharge

0.13

0.53

44%

18

0.08

95% Confidence Intervals:

ns

 

ns

 

Any infection

To hospital discharge

0.47

0.72

17%

12

0.036

95% Confidence Intervals:

0.53 to 0.98

 

7 to 199

 

Mortality

To hospital discharge

0.02

0.48

51%

97

0.15

95% Confidence Intervals:

ns

 

ns

 

 

EBM questions:

 

  1. Do the methods allow accurate testing of the hypothesis?  The methods allow    accurate testing but as with any meta-analysis the quality of the results depends on the quality of the studies included.  The trials included in this meta-analysis were small and ‘of doubtful quality’.  However, they have similar outcomes.

  2. Do the statistical tests allow correctly test the results to allow differentiation of statistically significant results?  Yes

  3. Are the conclusions valid in the light of the results?  The statistical tests are appropriate and the conclusions are reasonable given the small number and ‘doubtful quality’ of the studies.

  4. Did results get omitted and why?  No results were omitted.  

  5. Did they suggest areas of further research?  The authors suggest a large adequately powered trial to assess early enteral feeding in elective gastrointestinal surgery patients.

  6. Did they make any recommendations based on the results and were they appropriate?  They suggest that on the basis of this meta-analysis there seems to be no clear advantage in keeping patients nil by mouth after elective gastro-intestinal surgery, and that early feeding may be of benefit.

  7. Is the study relevant to my clinical practice?  This study relates to elective surgical patients whom the Intensivist may encounter in the high dependency unit or ICU.

  8. What level of evidence does this study represent?  1-, as the meta-analysis was of a small number of heterogeneous RCTs. 

  9. What grade of recommendation can I make on this result alone? N/A.

  10. What grade of recommendation can I make when this study is considered along with other available evidence? C, as the other available evidence consists of small heterogeneous trials and one meta-analysis (Marik- see CAT).

  11. Should I change my practice because of these results?  Many units are already feeding their patients early in the intensive care setting. Elective surgical patients usually have their feeding controlled by surgeons but we can contribute to the discussion regarding whether to feed them early

  12. Should I audit my current practice because of these results? Although this is only a grade C recommendation, it represents the best available evidence: you should probably audit your feeding practice.

 

Appraised by: Marcia McDougall; 28th March 2005. Email: marcia@dsl.pipex.com


Kill or Update By: 30/05/10

 

Reviewed & Edited by BC & GI

 

Citation: EBM Critical Appraisals. Scottish Intensive Care Society EBM Group. McDougal M. 2005. Lewis SJ, Egger M, Sylvester PA, Thomas S. Early enteral feeding versus 'nil by mouth' after gastrointestinal surgery: systematic review and meta-analysis of controlled trials. BMJ 2001; 323: 773-776

 

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