EARLY ENTERAL FEEDING VERSUS ‘NIL BY MOUTH’

1. EARLY ENTERAL FEEDING VERSUS ‘NIL BY MOUTH’ Journal Club Presentation December 2001 Presenter: Jui Tham Mentor: Dr G Keogh

2. BACKGROUND • Many patients are relatively undernourished prior to surgery. • Physiological response to starvation – glycogen, proteins, fats as energy sources. • Nutritional depletion is an independent determinant of serious complications post major GI surgery. • Enteral nutrition versus TPN • Is early enteral nutrition safe? If so, could it be clinically beneficial?

3. SEARCH • Medline search. • Keywords: enteral nutrition and randomized controlled trials (limited to english and human) • Results: 8 articles (7 reviews and 1 meta-analysis.

4. Early enteral feeding versus ‘nil by mouth’ after gastrointestinal surgery: systematic review and meta-analysis of controlled trials • Authors: SJ Lewis, M Egger, PA Sylvester, S Thomas. • Objective: To determine if a period of starvation post GI surgery is beneficial. • Rationale of NBM post GI surgery is to prevent post-op N&V and to protect an anastomosis. • Post-op dysmotility predominantly affects stomach and colon; the small bowel recovers function 4-8 hours post-laporotomy.

5. Method of Selection • Eligibility criteria: Elective GI surgery with patients randomly allocated to receive either enteral feeding (within 24 hrs of surgery) or NBM/IV fluids with introduction of enteral fluids and diet as tolerated. • Searches were made of PubMed, Embase and Cochrane databases and further unpublished data was sought with letters sent to pharmaceutical companies and authors of the trials included in the study.

6. Outcomes Analysed • Anastomotic dehiscence • Infection of any type • Wound infection • Pneumonia • Intra-abdominal abscess • Vomiting • Mortality • Length of hospital stay

7. Results • 13 randomised controlled trials were found. 2 were excluded as no information on relevant outcomes was given. • Additional unpublished data was obtained for 6 of the remaining 11 studies.

8. Characteristics of the 11 trials

9. Comment on Quality of Trials • Only 4 of the trials outlined the exact method of randomisation. • Only 1 study had blinded outcome assessments.

12. Length of hospital stay • Reported in all 11 studies. • Mean length of stay 6.2 to 14.0 days in early feeding groups and 6.8 to 19.0 days in control groups. • Significant reduction by 0.84 day (P=0.001).

13. Summary of Authors’ Findings • No clear advantage in keeping pts NBM after elective GI surgery. • Early enteral feeding may be beneficial (decreased risk of infection of any type and length of hospital stay). • Suggested an adequately powered clinical trial.

14. “A Prospective, Randomized Trial of Early Enteral Feeding After Resection of Upper Gastrointestinal Malignancy” MJ Heslin, et al. Annals of Surgery 226: 4; 567-80. 1997. • 195 patients undergoing resection of neoplasms of the oesophagus, stomach, pancreas and distal bile duct were randomised to receive either intravenous crystalloid post-op (control) or enteral feeding via jejunostomy tube. • Feed consisted of supplemented Impact (boosted with arginine, RNA, omega-3 fatty acids, vitamins and minerals). • Feed commenced within 24 hours of operation. • Advanced to 25kcal/kg/day.

21. “Early Feeding After Elective Open Colorectal Resections: A Prospective Randomized Trial.” BT Stewart et al. ANZ J Surg. 1998. 68; 125-8. • 80 patients who underwent elective colorectal resection with anastomosis and without stoma formation. • Randomised to early feeding group (free fluids from 4 hrs post-op to solid diet day one post-op) or control group (NBM until passage of flatus or bowel motion).

25. Strengths and Weaknesses • Heterogeneity of studies. • Doubtful methodological qualities of many of the studies. • Incomplete outcomes for many of the studies. • Acknowledgement of limitations of analysis and need for further adequately powered trials.