Gary M. Levine

Small Intestinal Mass of the Rat is Partially Determined by Indirect Effects of Intraluminal Nutrition

Although intraluminal nutrition presumably maintains small intestinal mass by direct contact with the epithelial cells, hormonal or neurovascular elicited by feeding may play an indirect role. In order to test for the presence of indirect factors, Thiry- Vella fistulae were created from the proximal small intestine of two groups of rats. The bypassed gut of a group of rats receiving an elemental diet intravenously was compared to a second group receiving the same diet by intragastric infusion. After 1 week, there was significantly greater (P less than 0.01) gut weight, mucosal weight, DNA content, and protein content of both the gut in continuity and tje bypassed gut of intragastric infused rats. Total sucrase activity was also greater (P less than 0.01) in intragastric fed rats, and this was due to both a greater protein content and specific activity (P is less than 0.05) of the gut in continuity and to the greater protein content of the bypassed gut. Serum gastrin levels were similar (P less than 0.05) in both groups, suggesting that gastrin may not play a role in initiating the differences reported. This study suggests that intraluminal nutrition maintains the small intestinal epithelial population in part, indirectly, by unidentified hormonal or neurovascular stimuli.

Serum albumin is predictive of 30-day survival after percutaneous endoscopic gastrostomy.

BACKGROUND Percutaneous endoscopic gastrostomy (PEG) tubes have been used since 1980 in patients who require prolonged enteral feeding. PURPOSE To identify factors associated with poor survival (defined as survival < 30 days) post-PEG. METHODS We assessed a cohort of 64 patients consecutively referred for a percutaneous endoscopic gastrostomy tube in a single, tertiary care hospital. Prior to PEG tube placement, we evaluated relevant clinical variables in each patient to determine their effect on 30-day mortality. RESULTS Of the cohort, 43 of 64 (67.2%) survived at least 30 days after tube placement. One death was attributable to tube placement. Bivariate analyses showed that 30-day survival correlated directly with serum albumin (r = .253; p = .049) and inversely with creatinine (r = -0.255; p = .042). Using multivariable logistic regression analysis, only albumin was identified as an independent predictor of 30-day survival (p = .044). Eighty-three percent of patients with a serum albumin > or = 3.0 g/dL survived 30 days compared with 58% with an albumin < 3.0, a difference of 25% (95% CI, -2% to 54%; p = .07). CONCLUSIONS In conclusion, serum albumin appears to be a predictor of early survival in individuals undergoing percutaneous endoscopic gastrostomy tube placement.

Direct and Indirect Effects of Dextrose and Amino Acids on Gut Mass

Oral intake of an elemental diet maintains small intestinal mucosal mass compared to the atrophy seen after intravenous infusion of the same diet. The greatest difference in intestinal mass occurs in the proximal bowel and is thought to occur because of rapid absorption in the proximal small bowel. This study was designed to determine the effects of the individual components of the elemental diet and their site of administration within the small bowel on small intestinal mass. Rats were maintained on intravenous alimentation and the proximal gut (by intragastric infusion) or the ileum was continuously infused with equal volumes of 30% dextrose, 5% dextrose, 5% amino acids, saline, or 30% mannitol. After 1 week of combined intravenous alimentation and gut infusion, the rats were killed and parameters of small intestinal epithelial mass were determined sequentially for the entire bowel. Although saline- and mannitol-infused controls did not differ from uninfused intravenously fed rats, proximal infusion of 30% dextrose reproduced the effects of a complete elemental diet. Proximal infusion of amino acids but not 5% dextrose had a limited effect on the duodenum and jejunum. Ileal infusion of 30% dextrose led to local hyperplasia of the site of infusion and in addition produced hyperplasia of the proximal gut. Ileal amino acid infusion, but not 5% dextrose infusion, led to local ileal hyperplasia. We conclude that: (1) intraluminal dextrose and amino acids have direct effects in maintaining gut mass (2) the gut is more responsive to amino acids compared to 5% dextrose, and (3) ileal 30% dextrose infusion leads to remote effects in the proximal gut, perhaps mediated by hormonal or neurovascular factors.

The Medical and Financial Costs Associated with Termination of a Nutrition Support Nurse

BACKGROUND Cost-containment pressures have adversely affected hospital nutrition support team staffing. We determined the effect of termination of a nutrition support nurse responsible for patients receiving total parenteral nutrition (TPN) on quality assurance and financial indicators. METHODS A retrospective review of all 1,093 patients receiving TPN from fiscal year (FY) 1992 through FY 1998 in a tertiary care community hospital. We documented the changes in care during years when the nutrition support nurse position was staffed, terminated, and restored. Indicators studied included inappropriate TPN, central venous line sepsis, TPN wastage, and estimates of preventable costs. RESULTS When the nurse was present, 8.6% of TPN patients had a functional gastrointestinal (GI) tract and inappropriately received TPN compared with 12.1% when the nurse was absent, a risk difference of 3.5% points (95% confidence interval [CI], -.06 to 8.3; p = .069). Risk of TPN-associated line sepsis increased from 8.8% of patients when the nurse was present to 13.2% when the nurse was absent, a difference of 4.4% points (95% CI, 0.06 to 9.2; p = .028). In the absence of the nurse, 26.3% of TPN patients had preventable charges vs 17.5% when the nurse was present (p < .0001). Total preventable charges were higher in the years without a nurse (p < .003). Total preventable costs increased by

Effect of Short-Chain Fatty Acids on Colonic Function and Structure

38,148 to

Impact of a Quality Assurance Program on Gastrointestinal Endoscopy

194,285 (depending on the estimate for sepsis) in the year after termination. Reinstatement of the nurse resulted in a decrease in costs between

Feeding Tube-Induced Pneumothorax

34,485 and

Bone and mineral status of patients beginning total parenteral nutrition.

156,654. CONCLUSIONS Adequate staffing of a nutrition support team reduced inappropriate TPN and complications of TPN. Financial savings of the same order of magnitude as the nurses compensation accompany substantial decreases in patient morbidity.

Luminal and metabolic regulation of jejunal amino acid absorption in the rat

Short-chain fatty acids (SCFA), fermentation products of fiber, are believed to play a role in intestinal adaptation. Although the administration of fiber or the infusion of SCFA has been shown to cause colonic growth, studies have been done primarily in enterally fed animals. In addition, the effects of SCFA on absorptive function have not been determined. Adult male rats were maintained on total parenteral nutrition (TPN) and, in addition, received either 150 mmol/L of saline or 150 mmol/L of SCFA mixture (60:25:15, acetate:propionate:butyrate) into the proximal colon. One week later, the in vivo absorption of water, electrolytes, and 20 mmol/L of butyrate was measured. After the rats were killed, parameters of colonic mass were determined. SCFA infusion into the colon had no significant effect on absorptive function. However, significantly greater mucosal height (p less than .01) and mucosal DNA (p less than .05), were observed. Although SCFA has a modest effect on colonic structure, they do not influence absorptive function in TPN rats.

Effect of fiber and its fermentation on colonic adaptation after cecal resection in the rat.

The impact of a quality assurance committee on documentation and use of gastrointestinal endoscopy was assessed. The committee, fulfilling Joint Commission on Accreditation of Healthcare Organizations criteria, performed retrospective (1984-1985) and prospective (1986-1988) reviews of all endoscopies. Criteria were developed from American College of Physicians and American Society for Gastrointestinal Endoscopy guidelines. All reviews of procedures that were questioned were returned to physicians for clarification. After reconsideration of the response, procedures were judged either justified or unjustified. There has been significant improvement in the quality of endoscopy reporting and documentation. The rate of questioned procedures decreased from 21.6% (95% confidence interval (CI), 20.1-23.1) in 1984-1985 to 9.2% (95% CI, 7.9-10.4) (P less than 0.01) in 1988. Improvement in use was reflected in the significant decrease in the rate of unjustified procedures from 8.2% (95% CI, 7.2-9.2) in 1984-1985 to 1.5% (95% CI, 1.0-2.0) (P less than 0.01) in 1988. Most importantly, this process curtailed the previously noted 10% annual increase in the number of endoscopic procedures (P less than 0.01).