A reappraisal of the peptide-based enteral formulas: clinical applications.

The development of peptide-based enteral formulas is a significant milestone in the advancement of nutritional care of the nutritionally compromised patient. Although previously limited to specific gastrointestinal mucosal diseases, the use of peptide-based formulas has been extremely useful in the critically ill patient with impaired gastrointestinal absorption associated with hypoalbuminemia resulting from hypermetabolic states. Based on previous animal studies, several investigators have noted improved nitrogen absorption, greater nitrogen utilization, higher branched chain amino acid levels, and increased insulin secretion with the use of peptide-based formulas compared with intact protein or free amino acid diets. Recent studies have indicated an improved gastrointestinal tolerance with peptide-based diets, with the rate of absorption and the degree of tolerance dependent on the presence of small molecular weight peptides. In addition, we have found that the critically ill patient suffering from severe hypoalbuminemia frequently develops a protein-losing enteropathy, which can be attenuated by the use of a peptide-based formula. Thus, peptide-based formula may attenuate albumin turnover in the intestine and thus be efficacious in patients with a protein-losing enteropathy from a variety of etiologies (table 2). We therefore recommend that enteral support with a peptide-based diet is safe and extremely useful in the catabolic, critically ill patient or in patients with significant gastrointestinal malabsorption associated with a protein-losing enteropathy. Tolerance of these formulas is dependent on the catabolic state of the patient, with more catabolic patients needing higher concentrations of nitrogen in the form of peptides and/or supplemental parenteral branched chain amino acids.(ABSTRACT TRUNCATED AT 400 WORDS)