Patients Receiving Nutrition Support Research Articles

Antipyrine clearance in surgical patients maintained on hypocaloric peripheral parenteral nutrition.

Antipyrine clearance (CLAP) constitutes a sensitive indicator of hepatic microsomal enzyme activity providing specific information on hepatic function. The purpose of this study was to evaluate the influence of hypocaloric peripheral parenteral nutrition on CLAP in patients receiving nutrition support after elective surgery. CLAP was measured in 15 patients before elective gastrointestinal surgery and 6 days after the surgery. Antipyrine (1 g) was administered orally, and CLAP was determined by the one-sample method. Subjects received a postoperative 786 kcal/d regimen providing 66 g of amino acid per day and 133 g of glucose per day for 5 days. Nutritional status was evaluated by anthropometric parameters. A control group of 15 patients received no postoperative hypocaloric peripheral parenteral nutrition but received conventional fluid therapy. Mean CLAP was increased by 61% (0.66 +/- 0.06 mL/min.kg-1 body wt vs 0.41 +/- 0.05 mL/min.kg-1 body wt in the preoperative period; p < .001), and antipyrine half-life was reduced by 42% (10.9 +/- 1.0 hours vs 18.9 +/- 2.0 hours; p < .001) after 5 days of hypocaloric peripheral parenteral nutrition. No significant modification was shown among control patients in CLAP (0.54 +/- 0.07 mL/min.kg-1 body wt vs 0.46 +/- 0.05 mL/min.kg-1 body wt in the preoperative period) or in antipyrine half-life (14.0 +/- 1.4 hours vs 16.5 +/- 1.8 hours). No significant correlation was observed between CLAP changes and those for the nutritional status of the patients. The results of our study indicate that oxidative drug-metabolizing capacity is increased in surgical patients maintained on hypocaloric peripheral parenteral nutrition. Clinicians should be conscious of the potential of this effect for altering the efficacy or toxicity of many therapeutic agents.

Is There a Role for Albumin Administration in Nutrition Support?

To review the administration of exogenous albumin in patients receiving nutritional support and determine if the use of albumin is supported by controlled trials. MEDLINE search of English-language literature using the key terms albumin, parenteral nutrition, and enteral nutrition. The references of articles identified were also searched. Studies examining the administration of exogenous albumin to hypoalbuminemic patients receiving nutrition support. Results from prospective randomized trials are presented in detail. Data from noncontrolled and animal studies are presented in areas where human controlled trials are limited. Albumin is a marker of malnutrition and numerous studies have demonstrated that a low serum albumin concentration is associated with increased morbidity and mortality. Investigators have attempted to improve outcome through the administration of exogenous albumin. The results of controlled trials examining exogenous albumin administration have been equivocal. One study demonstrated a significant decrease in overall complications, pneumonia, and sepsis. In two other controlled trials, albumin administration failed to decrease complications. None of the studies demonstrated a significant decrease in mortality or length of stay. A low serum albumin concentration has also been linked to intolerance to enteral feedings. Although case reports and one study support the administration of albumin, two prospective controlled trials have failed to demonstrate improved tolerance to enteral feeding in hypoalbuminemic patients receiving exogenous albumin. Evidence to date is insufficient to support the routine administration of exogenous albumin to hypoalbuminemic patients receiving nutrition support.

Hepatobiliary complications in adults receiving nutrition support.

Hepatobiliary dysfunction in patients receiving nutrition support is frequent. Other reasons for elevated enzyme levels including drugs, recent anesthesia and surgery or sepsis often coexist. Liver test abnormalities in adults are usually milder than in children and frequently self-limited and are 10 times more likely to occur with total parenteral nutrition (TPN) than tube enteral nutrition. Patients on short-term TPN usually have mild-to-moderate elevations in transaminase and alkaline phosphatase levels and steatosis or portal triaditis on biopsy. Patients who are infected while on TPN are at greater risk of developing steatosis and intrahepatic cholestasis. Strategies to correct abnormalities include alteration of the caloric mix in the TPN, cyclic infusions, metronidazole, enteral nutrition and inclusion of L-glutamine in the TPN formula. Patients on long-term home parenteral nutrition may develop persistent elevations in liver tests and steatohepatitis. Both acalculus and calculus cholecystitis occur with increased frequency in patients on long-term TPN. Biliary sludge precedes calcium bilirubinate stones: predisclosing factors include nil per os, prior ileal resection and use of narcotics or anticholinergics.

Invited Review: Infection Control of Parenteral Nutrition Solutions

Microbial contamination of parenteral nutrition solutions is a preventable cause of in patients receiving nutrition support. The components of the parenteral nutrition solutions have variable microbial growth potential. Crystalline amino acid and dextrose solutions are poor growth media for bacteria but may support fungal growth. Lipid emulsions provide an excellent medium for growth of bacteria and fungal species. Total nutrient admixtures will support microbial growth better than standard parenteral nutrition solutions will but less well than will lipid emulsion alone. Control of infection related to contaminated infusate depends on compounding procedure, quality control, appropriate storage, and procedures to prevent in-use contamination. Guidelines are presented for the preparation and administration of parenteral nutrition infusates that will minimize microbial contamination.