Foscarnet-induced electrolyte abnormalities in a bone marrow transplant patient receiving parenteral nutrition.

Cytomegalovirus (CMV) is a serious complication of immunosuppressed patients receiving bone marrow transplantation. Foscarnet, a pyrophosphate analog, has been used in the treatment of CMV infections. Renal impairment and electrolyte abnormalities are potential adverse reactions associated with the use of foscarnet. We report a case of significant electrolyte changes after initiation of foscarnet in a bone marrow transplant patient receiving parenteral nutrition.

Enteral feeding solutions.

There has been a widespread proliferation of enteral feeding solutions for general and specific therapeutic use. This article reviews the nutrient substrates and physical characteristics of these solutions with consideration to both psychological and clinically-proven principles pertinent to their application. The rationale for the composition and efficacy studies of disease-specific solutions also is presented.

Indirect calorimetry: technical aspects.

Indirect calorimetry measures oxygen consumption and carbon dioxide production to calculate resting energy expenditure and respiratory quotient. The respiratory quotient can be determined from indirect calorimetry to determine substrate utilization and used to alter the patient's nutrition support regimen. All but one indirect calorimeter manufactured in the United States are open-circuit rather than closed-circuit systems.

Rationale and efficacy of specialized enteral nutrition.

Enteral nutrition, whenever feasible, is the preferred route of nutrition support. There has been a tremendous increase in the number of enteral products available on the market. Many of these are designed for use in specific disease states. This review will summarize the scientific rationale and supporting research for specialized enteral nutrition.

Selection of nutrition support regimens.

The selection of a nutrition support regimen should be the product of a logical, stepwise process. After an appropriate candidate is selected, the integrity and function of the gastrointestinal tract must be assessed to determine if nutrients can be administered enterally or must be given by vein. The anticipated length of therapy will help determine the type of feeding access. Long-term nutrition support requires permanent access, such as a percutaneously or surgically placed feeding tube for enteral nutrition or a tunnelled catheter or implanted port for parenteral nutrition. Formula selection for enteral nutrition, providing adequate liver and renal function, depends largely on the patient's ability to assimilate intact nutrients. The primary decision in parenteral formula selection is whether to provide the macronutrients as a mixed fuel system. The ultimate goal of nutrition support is to make a smooth transition to oral feedings while maintaining adequate nutritional intake.

Psychosocial issues of nutritional support. A multidisciplinary interpretation.

In many cases, initiation of specialized nutritional support is a final attempt at medically managing illness for which other treatments have failed. Patients may have suffered for months or even years with their underlying diseases and are usually aware that poor response to nutritional support and concurrent therapies may lead to surgical intervention or more complex treatment. In some cases, there may be few alternatives left to pursue. For such patients, this paints a very stressful picture. If we as caregivers are empathetic to each patient's situation, we are better able to offer the support that these patients need. Health care professionals must keep patients informed of treatment plans and encourage participation in the planning process--during hospitalization, through the discharge phase, and after hospitalization. We need to pay close attention to those needs, whether nutritional support is short-term during hospitalization, prolonged, or permanent. The health care environment is demanding greater proficiency in cost containment and quality assurance in the delivery of care. Complex patient cases are becoming more difficult to manage as time constraints and resources become more restrictive. The ingenuity and imagination of health care providers trying to find ways to continue providing high-quality and safe care to patients are being tested daily. These worthwhile goals can be met only through cooperation, communication, and support among all levels and disciplines involved with the delivery of care. Feelings of helplessness, dependence, and loss of control can be diminished if health care providers maintain optimistic, confident attitudes, offer positive reinforcement for patients successes, and try to restore hope during this stressful period in patients' lives.

Efficacy of two elemental diets: a pair feeding study.

The efficacy and side effects of two elemental diets were studied. Twenty young Sprague-Dawley rats were fed one of three different diets. Group I (n = 7) was fed Vivonex-HN (VIV) ad lib; group II (n = 7) was given Criticare-HN (CRI), pair-fed to group I (the two elemental diets were given in glass bottles); group III was fed regular rat chow and served as control (CON). Body weight (WT), food intake, and nitrogen balance (NB) were measured daily. After 21 days, change in body weight was similar in the three groups (VIV = 64.9 +/- 3.2%; CRI = 59.6 +/- 3.3%; CON = 63.9 +/- 4.8%). Cumulative nitrogen balance was also similar in the two groups fed elemental diets (VIV = 4788 +/- 277 mg N; CRI = 4690 +/- 118 mg N), but in both these groups it was less than the control group fed chow (8060 +/- 85 mg N). Blood urea nitrogen (BUN) on the last day was higher in the VIV group (12.9 +/- 1.22 mg/dl) than in the CRI group (9.43 +/- 0.43 mg/dl), but in both study groups it was lower than in the CON group (17.2 +/- 1.08 mg/dl), although nitrogen intake was higher in the control (ad lib) group. SGPT was similar in the two elemental diets but higher than in CON. Liver weights were higher in the CRI group, probably abnormally so and likely due to increased fat content. Both diets had similar efficacy in nutritional support.

The effect of a new branched chain--enriched amino acid solution on postoperative catabolism.

Branched-chain amino acids (BCAAs) may regulate muscle amino acid flux. Metabolic studies of both experimental animals and humans utilizing comparatively large amounts of BCAAs infused with hypocaloric glucose have shown that catabolism and proteolysis can be blunted. These studies suggested that the nitrogen-sparing properties of amino acid solutions used in postoperative trauma or sepsis might be improved by increasing the amount of BCAAs. This hypothesis was tested on ten patients undergoing operations of moderate severity utilizing a peripheral amino acid mixture with a branched-chain:non-branched-chain ratio of 45:55% given in 5% dextrose. The patients received 1.7 gm of protein equivalent/kg of ideal body weight in 5% dextrose-crystalloid solution with a concentration of 3.5% amino acids for the first 5 postoperative days. Nitrogen balance, 3-methylhistidine excretion, blood chemistries, and plasma amino acid profile tests were done daily. The results showed that nitrogen equilibrium was maintained for 5 postoperative days without any untoward effects on patients, their surgical wounds, or hepatic function. Plasma amino acids showed no significant changes from baseline with the exception of elevations of the BCAAs. We conclude that this 45% BCAA-enriched solution may be safely administered to patients with postoperative traumatic injury and results in nitrogen equilibrium over a 5-day period.