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In total parenteral nutrition (TPN) of premature infants, glycero- and glucose-phosphate have been recommended, and clinically used, because of their considerable compatibility with calcium. However, a systematic comparative in vitro assessment of the therapeutic potential and safety of these substances has not yet been provided. We investigated the stability of TPN solutions containing calcium-gluconate and glycero- or glucose-phosphate in high concentrations. Evaluation was performed by visual inspection, absorptiometry, light microscopy, measurement of pH, and determination of calcium concentration before and after microfiltration. Even under circumstances promoting precipitation of calcium and phosphate--such as body temperature, relatively high pH, and concentrations of calcium and phosphorus exceeding those necessary to provide intrauterine accretion rates, all but one of the examined TPN admixtures remained stable. Our data suggest that the use of glycero-phosphate, and particularly glucose-phosphate, together with calcium-gluconate, is an uncomplicated and safe procedure to administer simultaneously high amounts of calcium and phosphorus in TPN of premature infants.

Three hearings on the diet industry took place during 1990 in the House of Representatives' Small Business Subcommittee on Regulation, Business Opportunities and Energy. Testimony from service organizations and consumers resulted in specific recommendations being made regarding consumer-protection standards. In addition, options for developing stricter regulatory standards were discussed.

Commercial diet programs, although numerous throughout the United States, are having little impact on the ever-growing overweight population. Dietitians and clinicians working with overweight clients should focus intervention strategies on the concept of replacing the "diet mentality" with a total life-style approach to weight management through improved eating behavior and regular physical activity.

Essential amino acids, found in abundance in high-quality dietary protein, are required daily by hospitalized patients and healthy persons to maintain the dynamic process of protein metabolism. One method for assessing dietary protein quality is by determining a diet's chemical score, ie, the ratio of a gram of the limiting amino acid in a test diet to the same amount of the corresponding amino acid in a reference diet (eg, whole-egg protein) multiplied by 100. This investigation used the chemical score to evaluate the protein quality of 9 parenteral and 17 enteral diets commonly used to feed hospitalized patients. Standard parenteral and enteral products (ie, formulas that had not been designed for patients with a specific disease state) had chemical scores that ranged from 46% to 70%. Limiting amino acids were either methionine (plus cysteine) or phenylalanine (plus tyrosine). Products designed for patients with renal failure had the highest scores, which ranged from 85% to 145%. Products that were enriched with branched-chain amino acids for trauma patients had scores that ranged from 38% to 73%. The only product available for patients with pulmonary compromise had a score of 50%. The lowest scores, which ranged from 5% to 13%, were found in products for patients with hepatic failure. All products, except those with chemical scores below 13%, may be fed in relatively small amounts of protein (7 to 33 g) to satisfy the minimum daily requirements of essential amino acids, although such levels would not meet minimal daily nitrogen requirements. We recommend that dietitians use the chemical score to assess the protein quality of parenteral and enteral diets.

The complementary feeding national programme (PNAC) delivers 2 kg-month of dried full-fat cow's milk (LP) to 0-1 year old infants. The purpose of this work was to design, produce and evaluate nutrient stability and shelf life of a modified LP milk formula (LPM), which seems nutritionally more adequate for infants and is of similar cost than LP, to be included into the PNAC. LPM has the following attributes: P% 12.0 (LP 21.8%): casein/whey proteins ratio: 40 to 50/60 to 50 (LP 80/20); more digestible fats; essential fatty acids: > or = 4% of total calories; vitamins and minerals which cover 100% daily requirements for 0 to 6 months old infants; protein and energy can be modulated between 1.5 and 2.25 g/100 ml and 50-75 kcal/100 ml respectively. Forty tons of LPM were produced in accordance with our specifications for a field study. Quality controls on the product showed the production feasibility of such a formula at a lower price than LP. To determine shelf life, periodical analysis of peroxides, available lysine, ascorbic acid and linoleic acid were carried out in LPM stored for 1 year at 20 degrees C and 37 degrees C. It was found that LPM has an optimum shelf life of 7 months when packed in the same material that is now being in use for LP.(ABSTRACT TRUNCATED AT 250 WORDS)

Recent advances in nutrition support methods now offer home patients the possibility of maintaining nutritional adequacy when intake is compromised. Using either enteral or parenteral feeding when appropriate allows patients to achieve an improved quality of life at home. Options for management offer a wide variety of choices in feeding methods, formulations, delivery systems, rates and scheduling as well as services provided for a given need. Team management of these patients is necessary to assure proper medical care and support.

Children with phenylketonuria (PKU) are treated with semi-synthetic diets restricted in phenylalanine. Low or phenylalanine-free formulae provide the majority of protein and energy in the diet while phenylalanine requirements are met by low-protein natural foods. Because of the restriction of natural protein sources in this diet, the study assessed the zinc and copper nutriture of treated children with PKU and correlated linear growth with zinc status. The plasma zinc of the PKU population was 66.6 +/- 3.3 micrograms/dl (mean +/- SEM). The hair zinc was 70.2 +/- 11.5 micrograms/g (mean +/- SEM). The mean plasma and hair zinc of the PKU population were significantly different (p less than 0.05) when compared to normal values of 84.2 +/- 2.9 micrograms/dl and 130.7 +/- 8.3 micrograms/g (mean +/- SEM), respectively. The dietary zinc intake of 10 PKU patients was 8.56 +/- 2.68 mg/day (mean +/- SD). No significant differences (p less than 0.123) were found when the mean zinc intake was compared with recommended dietary allowances for age of 10 mg/day. No significant correlations were found when plasma and hair zinc were plotted with height percentiles. Plasma copper of the PKU subjects (87.6 +/- 6.6 micrograms/dl, mean +/- SEM) was significantly less than that of normal young children (121.5 +/- 3.1 micrograms/dl, mean +/- SEM) despite a copper intake a 1.45 +/- 0.35 mg/day (mean +/- SD).

Neonatal Long-Evans hooded rat pups were assigned to one of three groups: 1) pups normally reared, 2) pups implanted with intragastric cannulas and artificially reared with a common milk replacement formula, 3) pups implanted with intragastric cannulas and artificially reared with a protein-enriched milk formula. Daily body weights were recorded, as were the ontogeny of various reflexes. On day 18, the animals were behaviorally tested and then killed. There were no differences among the three groups in daily body weights, nor in the ontogeny of reflexive behavior. There were no differences in the wet weights of caudal brain sections, but the normally reared animals had significantly larger rostral brain sections than either artificially reared group. While cerebella of normally reared animals were significantly larger than those of the two artificially reared groups, there was a significant trend towards more normal cerebellar weights with the addition of protein in the formula of artificially reared animals. Behavioral tests indicated that the animals artificially reared have significantly different behavior than normally reared animals. However, compared to animals artificially reared using a common milk formula, animals artificially reared with additional protein in their formula behave more like normally reared animals.

Due to calcium and phosphorus solubility problems in parenteral nutrition solutions, it is difficult to provide the premature infant with enough of these two minerals for adequate bone mineralization. In order to determine the maximum amounts of both Ca and P soluble in neonatal parenteral nutrition solutions, we employed the following procedure: (1) using concentrations of dextrose 10 to 25% and amino acid 0.5 to 4.0% with standard electrolyte and vitamin concentrations, Ca and P additions were sequentially made to determine the critical concentrations at which precipitates formed; (2) the pH of each test solution was determined; (3) all test solutions were incubated for 30 hr at room temperature; (4) following incubation, all tests were visually observed for calcium-phosphate crystals; (5) the solutions not obviously precipitated were filtered using black Millipore filters to determine the presence of any microprecipitates. Multiple graphs of Ca and P solubility in various dextrose/amino acid solutions were prepared from data generated by the study. The Ca and P interaction is primarily pH sensitive. Factors affecting the solution pH include both dextrose and amino acid concentrations. Our study showed that increases in amino acid concentrations enabled us to increase both Ca and P in the solutions.

The Authors studied the effectiveness and safety of a commercial hypocaloric diet on 11 obese postmenopausal women. During the experimental period 1 meal/day has been replaced with a chemically defined low calories product. Different parameters have been evaluated to assess the nutritional status 1), anthropometric: weight, skinfold thickness, arm muscle circumference; 2) biochemical total plasma proteins, transferrin, vitamins A, E, C, B12, folic acid; plasma iron, hemoglobin, MCV, RBC; 3) immune status (T lymphocytes and immunoglobulins). Moreover blood sugar, cholesterol and triglyceride levels, as well as blood pressure have been taken into account. All the possible side effects and the diet acceptance for all the patients have been scored. After 1 month all the abnormal conditions (weight, cholesterol, blood pressure) improved, while the nutritional status and immune response remained at an optimal level.

Technical considerations in the design, production, manufacture, process, and quality control of infant formulas are presented. Many of the criteria and systems used by manufacturers to assure the safety and adequacy of infant formulas have been codified by the U.S. Food and Drug Administration. Product label claims represent the minimum levels of nutrient that must be present throughout product shelf life. The precise nutrient level in an infant formula at any given time may differ from the label claim because of the variability of nutrient amounts contributed by major ingredients, a decrease of certain nutrients due to heat or oxygen exposure during processing, changes during storage, nutrient levels added to account for bio-availability, and the variation in analytical results. Infant formula manufacturers use various processes and quality control systems to assure the presence of appropriate amounts of each required nutrient in each batch. Infant formula manufacturers support the review of existing upper limits and the establishment of new limits where there is a justifiable and adequate basis to do so. Where needed, new upper limits should be set with appropriate consideration of existing technical factors affecting product formulation and nutrient content. Control of upper limits can best be achieved within the framework of existing regulations and manufacturing systems to assure that only batches of formula with appropriate levels of nutrients are introduced into commercial distribution.

Hospital malnutrition is a recognized condition that may be treated with a variety of feeding modalities. It is possible to achieve the goal of nutritional repletion with enteral feedings. Enteral feedings can now be prescribed for more types of patients because of our ability to better manipulate nutrition sources and the availability of modules and formulas designed for special use. The lower costs associated with enteral feeding have made it an option when nutritional support is required for a patient who has a functioning gastrointestinal tract.

Little is known about the specific effects of defined formula diets (DFD) on mucosal growth of the small intestine, pancreas, or liver. In the present study male Sprague Dawley rats weighing 220 to 250 g were fed isocaloric amounts of DFD (61 kcal/day) by continuous intragastric infusion. The diets fed were Vivonex, Vivonex-HN, Flexical, and Ensure. Oral chow-fed rats with intragastric water infusions served as reference. All groups gained weight: chow 50.50 g, Vivonex 21.17 g (P < 0.005), Vivonex-HN 25.40 g (P < 0.005), Flexical 30.5 g (P < 0.01), Ensure 39.29 g (NS). After 2 weeks rats were killed, the small bowel excised, rinsed, and divided into eight equal segments. Mucosal weight, DNA, and protein concentration per centimeter segment were measured. The pancreas was also removed, homogenized, and amylase activity assayed (units/g). Livers were excised, weighed, lipid content measured, and liver histology was examined by light microscopy. Mucosal weight, DNA, and protein concentrations per segment were decreased significantly in most bowel segments of DFD fed rats. Amylase activity per gram pancreas was significantly reduced in rats fed Vivonex, Flexical, and Ensure, Serum amylase activity was also lowered in animals on DFD. There was significant accumulation of lipid in the liver of Vivonex and Flexical animals (P < 0.01). Liver histology confirmed the striking increase in fat in the Vivonex and Flexical groups. These effects may result from differences in DFD absorption, mucosal metabolism, stimulation of enteric hormone release, and/or bile and pancreatic secretions.

There are two main routes for a central venous catheter to become infected and to produce septicemia: exogenous contamination from the skin or the hub, or from a contaminated infusate and endogenous seeding of the tip during bacterial and fungal episodes. Depending upon the patient population and medical and nursing care, one or the other mechanism may be involved. It is quite difficult to identify the route of infection in a single instance unless patients are enrolled in an ad hoc study protocol that guarantees the maximum safety in preparation of the solutions, administering them and managing the catheter. In critically ill patients, when the clinical picture is masked and confusing and the diagnosis is extremely difficult, a positive peripheral blood culture, a positive swab on the skin entry of the catheter or occasionally a quantitative culture of microorganisms from central blood that is higher than from peripheral blood dictates the removal or exchange of the catheter. Central venous catheter sepsis is usually resolved with catheter removal; however, in critical patients who still need the catheter in place, the risk of a new percutaneous catheter after removal of a suspected infected catheter must be weighted against the chance of resolving the sepsis by a simple exchange over a guidewire and long term irrigation of the new catheter with antibiotics.

Study A included 30 patients who received immediate postoperative enteral feeding with a nonelemental diet. The nonelemental diet was well tolerated. Study patients rapidly achieved nitrogen equilibrium and had a cumulative nitrogen balance of -11.1 g verus -46.7 g for the control group. In part B, 16 patients with varying degrees of bowel dysfunction received elemental and nonelemental diets in a crossover design. Patients with moderate small bowel impairment tolerated nonelemental better than the elemental diets. In those patients with more severe bowel impairment, the elemental diet was better tolerated. Nitrogen balance for both types of diet was similar in both groups of patients. It is concluded that nonelemental diets are better tolerated in most patients with moderate degrees of small bowel abnormality. In patients with severe bowel abnormality, elemental diets may be better tolerated, but nonelemental diets should still be the initial formula.

Ninety-seven patients with cancer, undergoing radiation treatment, were studied. Forty-two were given special dietary counseling and supplements of Sustagen or Isocal; 42 controls received no special advice or supplements. Thirteen patients were excluded because of poor prognoses and the ethical need for food supplements. Nutrient intake of all groups was assessed by 3-d diet records in household measures in the first and the last week of treatment. Intake was significantly higher in the adjunctive than the control group. The excluded group, despite supplementation, had intakes similar to the control group. No difference was observed between the control and adjunctive groups in clinical status at the end of treatment or in long-term outcome.

In intensive care it is usual to give from between 3000 and 4500 calories. It seems that an intake of 1 gram of nitrogen for 150 to 200 calories from a non-protein source allows the optimal utilization of nitrogen. The advances made in the manufacture of nutritional mixtures and the techniques of administration often allow high calorie/protein intakes by the oral route alone. Small calibre silicone tubes which are perfectly tolerated are now available. They avoid naso-pharyngeal, oesophageal and pulmonary complications, and there is no reflux. Continuous oral feeding usually given by a pump improves gastric tolerance, reduces the digestive secretions, and slows down the intestinal transit. Digestion and absorption are improved. This technique, as well as the new tubes, allows comatose patients to be fed without any risk. The use of refrigerated nutripompes avoids bacterial proliferation in the nutritional liquid, which can affect digestion. Furthermore these pumps reduce the work of the nurse. Various nutritional mixtures allow a high calorie intake despite the abnormal digestion in the patient. Complications of oral feeding are rare. Reactions of intolerance and the respiratory risks have been considerably reduced. Metabolic disorders can be easily avoided. Diarrhoea is the result either of bacterial proliferation or an error in administration. These complications are definitely less frequent and less serious than those of feeding by the intravenous route, and the precautions to be taken are much simpler. The method is also cheaper.

Low protein diets are used to treat infants and children with hyperammonemia due to urea cycle and other metabolic disorders as well as a number of amino and organic acidopathies. The incidence of these disorders is small and many are life-threatening. As a result, there is little in the literature on the dietary management of these patients. This paper draws on 10 years of clinical experience at the Hospital for Sick Children in Toronto, Ontario and presents a guide to the preparation of infant formulas providing levels of protein intake from 0.5 to 2.0 g per kg. Also described is a low protein equivalency system that is a useful guide for measuring both baby foods and table foods for affected children up to about six years of age. This dietary information is accompanied by a description of the disorders amenable to low protein diets, some of the adjunctive therapies employed and the nutritional concerns associated with severe restriction of protein.

The purpose of this paper is to attempt to define the upper limit of the safe range of protein intake, with particular reference to the protein content of prepared fixed-formulas used for feeding healthy, term infants. For discussion purposes we use the current upper limit proposed by the U.S. Food and Drug Administration (FDA), namely, 4.5 g protein per 100 kcal, as our initial reference level. To help reach a conclusion, the concept and definitions of nutritional adaptation and accommodation are considered, followed by a brief review of selected studies in full-term infants fed varying levels of protein intake. Based on growth and blood biochemical data, principally plasma free amino acid levels, we conclude that the currently proposed FDA upper limit is probably too high. The available data support a recommendation for lowering the value to about 3.5 g of protein per 100 kcal. Concerns for renal solute load (RSL) may require a further, desirable refinement in the value proposed. Indeed RSL should perhaps serve as the primary basis for establishing a rational and safe upper limit for the protein content of prepared fixed-formula diets for the very young, healthy infant.

Osmolalities of selected defined-formula products for use in treatment of inherited disorders of amino acid metabolism were measured at 12 energy concentrations. Osmotic behaviors of six carbohydrate modules as components of L-amino acid formulas were also studied. Osmolality measurements were made using a Wescor vapor pressure depression osmometer (model 5100 C). Phenyl-Free at concentrations greater than 10 kcal/oz yielded high osmolalities that exceeded the recommended level for infants. Lofenalac, Low Phe/Tyr Diet Powder, and MSUD Diet Powder at concentrations up to but no greater than 20 kcal/oz exerted osmolalities acceptable for use with infants. Low Methionine Diet Powder produced the lowest osmolality of the products tested. Differences among products can be explained by the formulations of the products, with sources of nitrogen and carbohydrate and percents of protein, carbohydrate, and fat considered. Carbohydrate type significantly affected formula osmolality; differences among carbohydrate sources can be attributed to their molecular sizes. Formulas that contained glucose exerted the highest osmolalities, while those with corn syrup or sucrose yielded the next highest. Protein Free Diet Powder, Polycose, and Moducal exerted reasonably low osmolalities.

Bacterial cultures were made on tube-feeding formulas provided to 35 unselected adult patients on termination of the infusion. Bacteria were counted and identified using routine procedures. Formulas were classified as nonmanipulated, manipulated, or locally prepared. Medical records were reviewed to determine if diarrhea was present during the period that included 2 days on either side of the sampling day. A significant association was observed between the extent of bacterial contamination and the presence of diarrhea (p = 0.027). Locally prepared and manipulated formulas contained a significantly greater number of organisms when compared to nonmanipulated formulas (x2 = 17.81, p less than 0.001). Counts for two baseline and four termination cultures on locally prepared formulas exceeded the acceptable limit for coliform organisms in pasteurized milk according to public health standards. Eight additional cultures on commercial feeding formulas which were presumably sterile initially, exceeded these standards at the end of the administration period. Thus 12 of 35 formulas (34%) would not meet public health standards applicable to pasteurized milk. Use of sterile nonmanipulated formulas in a closed administration set is recommended, along with routine, periodic bacteriologic surveillance of enteral feeding programs.

Careful medical and laboratory monitoring of 27 subjects during a 28-day use of a 330-calorie (Cal)/day liquid formula, with weight loss averaging 9.1 kg (range, 3.2 to 19.1 kg), included a 22-factor automated blood chemistry analysis, BP, hematology, urine analysis, lipid profile, delayed cutaneous hypersensitivity, differential cell count, ECG, and Holter monitoring. Results suggest that very-low-calorie diets can be an effective and safe means of substantial weight reduction. Cautions for specific individuals are noted. The possible beneficial effects on hypertension and on serum cholesterol and triglycerides levels are discussed.

The chemical stability of folic acid in 25% dextrose, 3.5% amino acids, and multivitamin solution was investigated. Solutions of 0.25, 0.5, 0.75, and 1.0 mg/liter of folic acid admixed in the study solution were prepared. Solutions were stored in light-room temperature, light-refrigeration, dark-room temperature, or dark-refrigeration. Samples were drawn to determine folic acid concentration and again at 4, 8, 12, 18, 24, 36, and 48 hr after admixture. Folic acid concentration was determined by competitive binding radioassay, and results are expressed as percent of initial folic acid concentration. Folic acid was stable for 48 hr with each tested concentration and stability was found to be independent of temperature or light storage effects. Folic acid admixed in the study solution is chemically stable for up to 48 hr after initial admixture under normal total parenteral nutrition storage conditions.

The authors conducted a three-month safety test of a textured soy (TS) product manufactured by the Agricultural Plant, Boly. Young male and female rats received semisynthetic diets containing 8, 18 and 38% of TS protein or casein supplemented with methionine, as the only source of protein. The effect of the diet containing 18% of TS protein on the growth, on certain parameters of protein and fat metabolism and on the zinc and copper status corresponded to that produced by 18% of casein supplemented with methionine. When the content of TS protein was lower or higher than the optimal (18%), the development of rats fell behind the control ones receiving adequate amount of casein. High doses of TS protein produced a favourable effect on lipid metabolism in the liver, but its effect on zinc metabolism was unfavourable. No signs of toxic action of the TS product were recorded during the three-month safety test of TS.

Use of refractive index measurements to assure accurate formulation of pediatric parenteral nutrient base solutions is described. The refractive indexes for various amino acid and dextrose concentrations were determined. An equation was derived to define the theoretical refractive index for combinations of amino acids and dextrose. Finally, a clinically acceptable range (deviation from theoretical) was determined. The actual refractive index for 300 pediatric parenteral nutrient solutions was compared with the calculated theoretical reading. The actual refractive index for all solutions was consistently predicted by the derived equation. Discussions with clinicians resulted in identification of an allowable range for these readings. All reading were within the identified range. The use of refractive index measurements is a valuable quality assurance tool for pediatric parenteral nutrient base formulations.

The solubility and stability of Ca and P in a parenteral nutrition solution is defined. In this study we demonstrate that high levels of Ca and P can be attained in parenteral nutrition solutions suitable for use in neonates. The efficacy and safety in neonates, however, will require specific study.

The trace mineral (chromium, copper, iron, selenium, and zinc) status of 10 children (4 to 13.8 years) with phenylketonuria (PKU) and 9 normal children (6.5 to 15.9 years) was assessed. The children with PKU were treated with a phenylalanine-free L-amino acid mix that supplied the following percentages (mean +/- standard deviation) of total daily intake: energy, 45 +/- 13; protein, 75 +/- 11; copper (Cu), 62 +/- 10; iron (Fe), 82 +/- 7; selenium (Se), 40 +/- 20; and zinc (Zn) 87 +/- 8. Diet records and blood samples were collected from each subject. Children with PKU had significantly greater mean intakes of Cu, Fe, and Zn than normal children. Mean serum Cu, Fe, and Zn concentrations of the children with PKU and normal children were not different despite significantly greater intakes by the children with PKU. Normal children had a significantly greater mean serum Se concentration and a mean blood chromium concentration 1.6 times that of children with PKU. Individuals whose primary source of protein is an elemental diet are especially at risk for multiple trace mineral deficiencies. Manufacturers of chemically defined medical foods should evaluate composition, specifically molar ratios between minerals, as a basis for product formulation.

This is a report of an in vitro study evaluating clotting ability of some formulas with intact protein and hydrolyzed protein sources in a series of buffers ranging from a pH of 1 thru 10. The following 10 products were tested: Ensure Plus, Ensure, Enrich, Osmolite, Pulmocare, Citrotein, Resource, Vivonex TEN, Vital, and Hepatic Acid II. Protein (10 and 20 g/liter) was added to Citrotein and Ensure Plus. All formulas were tested at full and some at half strength. Clotting occurred only in premixed intact protein formulas (Pulmocare, Ensure Plus, Osmolite, Enrich, Ensure) and in Resource. No clotting was observed for Citrotein (intact protein formula in powder form), Vital, Vivonex TEN, and Hepatic Aid II. Adding protein did not cause or increase clotting. In summary, clotting of some liquid formula diet appears to be an important factor causing possible gastric feeding tube occlusion. The following measures may help in preventing this problem: flushing before and after aspirating for gastric residuals to eliminate acid precipitation of formula in the feeding tube, advance the nasogastric feeding tube into the duodenum if possible, and avoid mixing these products with liquid medications having a pH value of 5.0 or less.