Effects of Small-Peptide and Whole-Protein Enteral Feedings on Serum Proteins and Diarrhea in Critically III Patients: A Randomized Trial

Abstract

Background: It has been proposed that enteral feeding formulas containing small peptides are more efficacious and better tolerated than whole-protein formulas in critically ill patients. Methods: Intensive care unit patients were stratified with regard to treatment with antibiotics and serum albumin and randomized to treatment with a small-peptide enteral diet or an isoenergetic, isonitrogenous whole-protein diet for 10 days. To assess efficacy, we measured serum prealbumin and fibronectin, and to assess tolerance, we monitored the incidence of diarrhea. A protocol was followed to ascertain all causes of diarrhea (defined as >200 g stool or ≥3 liquid stools on 2 consecutive days). Results: Fifty subjects completed the trial. Serum prealbumin and fibronectin increased between 21% and 36% in both groups, but the increase was significant only in the small-peptide group. The change in fibronectin between days 5 and 10 was significantly greater in the small-peptide group (p = .02). Diarrhea occurred in 10 subjects (17.8% of days) receiving small-peptide feeding and 4 subjects (7.5% of days) receiving whole-protein feeding (p = .07 for incidence and 0.03 for prevalence), but the difference was explained by the coincidental use of more diarrhea-causing medications in the former. Only one case of diarrhea could be attributed to tube feeding. Conclusions: During 10 days of feeding, the small-peptide diet produced slightly greater increases in serum rapid-synthesis proteins than did the whole-protein diet, especially between days 5 and 10. The clinical implications of this difference between the diets are unknown. Both small-peptide and whole-protein diets were well tolerated. (Journal of Parenteyal and Enteral Nutrition 21:162-167, 1997)