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)

Intestinal absorption of peptide enteral formulas in hypoproteinemic (volume expanded) rats: a paired analysis.

Previous studies have confirmed the improved tolerance of a peptide enteral compared to standard enteral alimentation in hypoalbuminemic, critically ill patients. Animal studies, including hypoproteinemic, volume-expanded rats, demonstrated that the protein hydrolysate of a peptide enteral formula was responsible for the enhanced absorption. The purpose of this study was to determine whether the composition of small MW peptides (protein hydrolysate) in two commercially available peptide enteral formulas would affect the rate of intestinal absorption and albumin clearance in intact jejunal loops before and during hypoproteinemia induced by iv infusion of Tyrode's solution in Sprague-Dawley rats. Net transmucosal water movement was calculated using a volume recovery method; albumin clearance was calculated using iv radiolabeled albumin. We studied three groups of animals during luminal perfusion with either Tyrode's solution, diet A containing 21% peptides, or diet B containing 56% peptides. When compared to luminal perfusion with Tyrode's solution (control animals), both diets significantly enhanced net transmucosal water absorption before volume expansion (p less than .05). With the induction of hypoproteinemia, diet B continued to stimulate water absorption when compared to control animals (p less than .01). Luminal perfusion with diet A failed to attenuate net water secretion induced by hypoproteinemia. Capillary and mucosal albumin clearance was similar for all groups studied. These findings suggest the percentage of small MW peptides may affect the rate of intestinal absorption in patients with acute kwashiorkor-like hypoalbuminemia.

Recovery from hepatic vein thrombosis (Budd-Chiari syndrome) complicating ulcerative colitis.

A 22-year-old female with active ulcerative colitis developed massive ascites, hypoalbuminemia, and hepatomegaly compatible with thrombosis of the hepatic veins. The diagnosis of Budd-Chiari syndrome was confirmed by ultrasonography, computed tomography, and by liver biopsy. A search of the literature disclosed only three previous reports of Budd-Chiari syndrome occurring in patients with ulcerative colitis. All patients have been young females with active colitis and no other known risk factor for the development of hepatic vein thrombosis. Our patient, unlike the previously reported patients who died, recovered sufficiently to be discharged from the hospital.

Intestinal absorption of elemental and standard enteral formulas in hypoproteinemic (volume expanded) rats.

We examined the influence of a peptide-based enteral formula and a standard (intact protein) enteral formula on intestinal transcapillary and transmucosal water and protein fluxes during hypoproteinemia induced by plasma volume expansion. In 15 Sprague-Dawley rats, net transmucosal water flux and net transmucosal and capillary albumin clearances were monitored in jejunal loops before and during intravenous infusion (2.5 ml/min/kg) of Tyrodes solution. This procedure resulted in a 60% reduction in plasma protein concentration and net water secretion into the bowel lumen. Luminal perfusion with the peptide-based formula did not modify the magnitude of the reduction in plasma protein concentration, yet dramatically reduced transmucosal and transcapillary albumin clearances (p less than 0.05). In addition, a net absorptive water flux was maintained with the peptide-based formula during volume expansion despite hypoproteinemia. The response to luminal perfusion with the intact protein formula were not different from controls. The results of this study are consistent with previous observations that enteral feeding with a peptide-based formula significantly attenuates the diarrhea associated with acute hypoalbuminemia in the critically ill patient.

Diarrhea associated with severe hypoalbuminemia: a comparison of a peptide-based chemically defined diet and standard enteral alimentation.

To demonstrate a relationship between diarrheal incidence and the onset of hypoalbuminemia developing as a result of acute protein-calorie malnutrition and severe catabolism, we initially studied two patients who had developed severe hypoalbuminemia (less than 2.5 g/dl) and diarrhea on a variety of enteral diets. Each patient was placed on a peptide enteral formula at a rate of infusion equivalent to that used during the previous 24 h. Diarrheal volumes decreased significantly from greater than 1500 to less than 100 ml/day and from greater than 4000 to 800 ml/day. We subsequently studied 12 patients in a randomized, prospective fashion to confirm our previous observations. Seven patients received a peptide enteral formula, and five received a standard isotonic enteral formula as a control. The patients were monitored for a minimum of 2 wk or until serum albumin levels reached 3 g/dl. Nutritional variables were measured initially and every 4 days for the duration of the study. Of the patients receiving the isotonic feeding, only one of five completed the study period without diarrhea. Two patients died unrelated to the feeding, and three patients developed severe diarrhea within 48 h of institution of the study. Of the seven patients receiving the peptide feeding, six completed the study period without diarrhea. One patient had a large stool volume initially which decreased by day 2 of the study. We conclude that a peptide enteral formula is well tolerated in patients with severe hypoalbuminemia when compared to a standard isotonic enteral formula. The ability to provide enteral nutrition in a form that is well tolerated in hypoalbuminemia patients may obviate the need for parenteral nutrition routinely in these patients.

Diarrhea in the intensive care unit: the role of hypoalbuminemia and the response to a chemically defined diet (case reports and review of the literature).

We describe five patients who developed acute kwashiorkor-like hypoalbuminemia during their hospitalization in the intensive care unit. With the initiation of enteral alimentation, diarrhea ensued and continued for at least 48 hours. Routine evaluation for the cause of diarrhea including stool culture for enteric pathogens, white blood cells, ova and parasites, Clostridium difficile cytotoxin, and flexible sigmoidoscopy was negative. When a peptide based formula (Vital HN, Ross Laboratories, Columbus, OH) was initiated, there was a significant reduction in stool output within 24 hours. In three of the five cases, hypoalbuminemia corrected within 2 weeks. Four of the five patients were discharged from the hospital. Although several reports have acknowledged the association between hypoalbuminemia and impaired gastrointestinal absorption, no previous enteral formula has been tolerated in these acutely ill patients until serum albumin levels had improved. Further studies will be required to confirm the better gastrointestinal tolerance of this peptide based formula in patients with severe hypoalbuminemia.

Multiple squamous papillomas of the esophagus associated with Goltz syndrome.

A 30-yr-old white female with a history of focal dermal hypoplasia (Goltz syndrome), chronic gastroesophageal reflux, and dysphagia was found to have, by barium esophagram and esophagogastroduodenoscopy, multiple 2- to 3-mm papillary projections in the distal esophagus and an esophageal stricture. Biopsy of these lesions revealed squamous papillomas and a benign stricture. Although chronic irritation from gastroesophageal reflux has been suggested as a possible etiology of acquired esophageal papillomas, the previous association of congenital papillomas of the oral mucosa in Goltz syndrome suggests that the multiple papillomas in this patient are congenital in origin.

Hypoalbuminemia as an indicator of diarrheal incidence in critically ill patients.

Recently, we noted that substantial numbers of critically ill patients admitted to a medical ICU developed diarrhea. We checked them for infectious, metabolic, and untoward medication effects, which were negative. We next considered a possible causal relation between reduced serum albumin and diarrhea. To document the frequency of diarrhea in this population, explore the relation between hypoalbuminemia and diarrhea, and make a preliminary assessment of a peptide-based, chemically defined diet in these catabolic patients, a study of consecutive medical ICU patients was begun. For each patient, we recorded the principal diagnosis, type of diet received, the frequency and volume of stool, and the serum albumin concentration at admission. When diarrhea developed, attention was paid to the serum albumin levels as well as the effects of various diets. Overall, 12 (34%) of 35 study patients developed diarrhea. No patient had a previous history of diarrhea, malabsorption, weight loss, or GI symptoms that may precede the onset of diarrhea. The stools from each patient with diarrhea were examined for enteric pathogens, ova and parasites, Clostridium difficile culture and cytotoxin assay, and qualitative stool fat, which were all negative. Every patient with a serum albumin level less than 2.6 g/dl developed diarrhea. No patient with a serum albumin level of 2.6 g/dl or greater developed diarrhea, regardless of the type of nutritional support received. Four of the 12 patients with hypoalbuminemia and diarrhea were placed on a peptide-based, chemically defined diet, after which their diarrhea resolved and their serum albumin concentrations increased.

Spontaneous bacterial peritonitis associated with an intrauterine device.

Intrauterine contraceptive devices (IUD) have been associated with the induction of chronic anaerobic endometritis as well as superimposition of exogenous sexually transmitted diseases and unilateral tubo-ovarian abscesses. We report an unusual case of spontaneous bacterial peritonitis in a patient with ascites and an IUD. Bacteriological data support the concept that the source of infection was a chronic mixed endometritis induced by prolonged use of an IUD (16 years). In the presence of ascites, a localized endometritis with its reservoir of bacteria provided the medium for systemic disease.

Acute lymphoblastic leukemia manifested as aortic occlusion.

A 36-year-old black man is described who presented with occlusion of the distal aorta and common iliac arteries by thrombus composed of fibrin and leukemic cells. On the basis of a review of the literature, this may be the first report of acute leukemia presenting in this manner.

Human botulism (type F)--a rare type.

An unusual presentation of type F botulism (one of the world's three reported outbreaks) is described. The diagnosis was complicated by the presence of pre-existing Adie's myotonic pupil. There was also a history of self-inflicted small-caliber gunshot wound to the right brain 10 years before the onset of the botulism. Post-traumatic seizure disorder, also present in this patient, was under good control. No offending food was ever discerned, despite exhaustive study.