Total parenteral nutrition in children

Pitfalls of Iron Supplementation in Parenteral Nutrition Admixtures for Children with Intestinal Failure

BACKGROUND

Pediatric patients with intestinal failure are at increased risk for iron deficiency. Supplementation is not routinely included in parenteral nutrition solutions. There is currently limited research related to the safety of iron supplementation in parenteral nutrition and for intravenous forms used in patients with intestinal failure. Current ASPEN and ESPGHAN guidelines promote the use of enteral iron, acknowledging the risks of using iron supplementation within parenteral nutrition admixtures.

METHODS

We review a patient case and the current available literature related to iron in parenteral nutrition.

RESULTS

Five major concerns are identified: peroxidation reactions, incompatibility, hypersensitivity, infection risk, and iron overload.

CONCLUSION

We propose an argument against the preferential use of iron supplementation within parenteral nutrition in children with intestinal failure when enteral supplementation or intermittent parenteral infusion may be sufficient.

CLINICAL RELEVANCY STATEMENT

Pediatric patients with intestinal failure are at risk for iron deficiency anemia, anemia due to folate or B12 deficiency, vitamin B6 deficiency, copper deficiency, non-anemic iron deficiency, and anemia of inflammation. Iron status assessment and supplementation for these patients is variable over time. There are several biochemical and physiologic concerns about the safety of adding iron supplementation to parenteral nutrition admixtures. This paper briefly reviews the current available literature. Further research is needed to evaluate best practices for iron supplementation for pediatric patients with intestinal failure. This article is protected by copyright. All rights reserved.

The role of parenteral lipids in the development of advanced intestinal failure-associated liver disease in infants: a multiple-variable analysis

BACKGROUND

Given the recent interest in the role of ω-6 lipids in the development of intestinal failure-associated liver disease (IFALD), the authors sought to examine the role of parenteral lipids in the development of a serum conjugated bilirubin >100 µmol/L (5.9 mg/dL; CB100) in infants.

METHOD

Between 2003 and 2004, data were collected prospectively on infants undergoing an abdominal surgical procedure. Univariate logistic regression models for the prediction of CB100 by 1 year postoperatively were developed. Predictors significant at the 0.2 level on univariate analysis were entered into a backward stepwise multiple variable logistic regression.

RESULTS

Of 152 infants who received parenteral nutrition (PN) postoperatively, 22 developed CB100. Predictors that met criteria for consideration in the multiple-variable model were age, weight, small bowel length, presence of a stoma, proportion of enteral feeds postoperatively, septic episodes, days of maximal PN amino acid (>2.5 g/kg/d), days of maximal lipid (>2.5 g/kg/d), and PN duration. The final model included septic episodes (odds ratio, 3.23; 95% confidence interval, 1.8-5.9) and days of lipid >2.5 g/kg/d (1.04; 1.003-1.06). At 60 days of maximal lipid, the odds of advanced IFALD were increased 10-fold.

CONCLUSIONS

This model suggests a key role of parenteral lipids and septic events in the development of CB100 from IFALD. These data may provide targets, such as careful line care, reduction in maximal lipid dose, or alternate lipids such as ω-3 fatty acids, to prevent CB100, an identified marker of subsequent liver failure from IFALD.

Metabolism and nutrition in the surgical neonate

Considerable improvements have been achieved in pediatric surgery during the last two decades: the mortality rate of neonates undergoing major operations has declined to less than 10%, and the morbidity of major operations has become negligible. This considerable improvement can be partly ascribed to a better understanding of the physiological changes that occur after an operation and to more appropriate management and nutrition of the critically ill and "stressed" neonates and children. The metabolic response to an operation is different in neonates from adults: there is a small increase in oxygen consumption and resting energy expenditure immediately after surgery with return to normal by 12-24 hours. The increase in resting energy expenditure is significantly greater in infants having a major operation than in those having a minor procedure. The limited increase in energy expenditure may be due to diversion of energy from growth to tissue repair. During parenteral nutrition, it is not advisable to administer more than 18 g/kg/day of carbohydrate because this intake will be associated with lipogenesis, increased CO(2) production, and increased free radical-mediated lipid peroxide formation. Glutamine intake is potentially beneficial during total parenteral nutrition, although a large, randomized, controlled trial in surgical neonates requiring parenteral nutrition is needed to provide evidence for its benefit.

Network approach to the child with primary intestinal failure

Intestinal failure (IF) is a rare condition resulting from short gut and other heterogeneous intestinal diseases. Major centers in Italy merged in a national network to build common diagnostic and management approaches and to investigate the natural history of IF. Gastroenterological reference centers with specific expertise in intestinal morphology, diagnosis of autoimmune conditions, intestinal microbiology and parenteral nutrition were identified to act as consultants to the network. These centers of expertise provided specific diagnostic approaches while ensuring high technical standards. The approach allowed each center to learn from a larger cohort of patient samples. A database was set up to investigate etiology, epidemiology and natural history of IF. A common diagnostic algorithm for intractable diarrhea was designed. This process was largely based on electronic communication among centers and specimen shipping. Etiologic diagnosis was obtained in almost all cases of IF secondary to severe protracted diarrhea. The study of the natural history of IF showed a close association between etiology of IF and its outcome. The natural history of IF also provided the starting point for specific therapeutic approaches to its complications such as parenteral nutrition-associated cholestasis and catheter-related sepsis. The network approach to IF provides an effective model to optimize resources and prospectively investigate the natural history of IF, essential steps to design interventions, including intestinal transplantation and improve the outcome of IF.

Natural history of intestinal failure, investigated through a national network-based approach

OBJECTIVES

Intestinal failure (IF) is a condition whose treatment requires advanced knowledge and techniques and a multidisciplinary approach. Intestinal failure is the endpoint of many intestinal diseases and may result in full recovery, in life-long parenteral nutrition, or in the death of the child. The aim of this study was to evaluate the natural history of IF in children using a national network of resources.

METHODS

Italian centers of pediatric gastroenterology merged in a national network, developing a collaborative management approach for children with IF. A consensus definition of IF was achieved. A database was set up to investigate the cause, epidemiologic factors, and natural history of IF.

RESULTS

One hundred nine children were enrolled in 5 years. The cause of IF was: short bowel syndrome (n = 48), disorders of motility (n = 16), structural enterocyte defects (n = 14), multiple food intolerance (n = 10), autoimmune enteropathy (n = 7), and others or unknown (n = 14). The eventual outcome was closely related to the primary cause, ranging from full and permanent intestinal sufficiency in children with multiple food intolerance to high death rate or total dependance upon parenteral nutrition in those with structural enterocyte defects. Intermediate outcomes were observed for the other causes. Four children received intestinal transplantation.

CONCLUSIONS

The network approach for IF provides an effective model to optimize resources and to investigate prospectively the natural history of IF. Based on the work on this series, a European network for IF could be an effective model for fulfilling the diagnostic and management needs, including intestinal transplantation.

Metabolism and nutritional support in the surgical neonate

Various factors can influence the metabolism of surgical neonates. These include prematurity, operative stress, critical illness, and sepsis. The nutritional management of surgical infants with congenital or acquired intestinal abnormalities has improved after the introduction of parenteral nutrition. This article is focused on the energy and protein metabolism of surgical neonates with particular reference to the metabolic response to operative trauma and sepsis. The metabolic utilization of intravenous nutrients also is discussed. The metabolic response to operative trauma is different between neonates and adults. Infants have high rates of protein turnover and are avid retainers of nitrogen. Energy expenditure increases only transiently (4 to 6 hours) after major surgery in neonates. Protein turnover and catabolism seems not to be affected by major operative procedures in neonates. In neonates on parenteral nutrition, carbohydrate and fat have an equivalent effect on protein metabolism. The main determinants of fat utilization are carbohydrate intake and resting energy expenditure. Parenteral nutrition in surgical neonates is associated with increased production of oxygen-free radicals. This seems to be related to intravenous fat administration. Promoting fat utilization by reducing the carbohydrate to fat ratio in the intravenous diet reduces free radical activity to a similar extent as fat exclusion. Glutamine appears to be safe for use in neonates and infants and is "conditionally essential" in very-low birth weight infants and in septic neonates. Enteral glutamine supplementation in very-low birth weight infants reduces the risk of sepsis. The metabolism of surgical neonates is affected by operative trauma, critical illness, and sepsis. Nutritional support in surgical neonates has a profound impact on outcome. Exogenous glutamine can modulate immune, metabolic, and inflammatory responses. Further investigations are needed to clarify the clinical benefit of parenteral or enteral glutamine administration in surgical neonates.

Energy metabolism, nitrogen balance, and substrate utilization in critically ill children

BACKGROUND

Critically ill patients are characterized by a hypermetabolic state, a catabolic response, higher nutritional needs, and a decreased capacity for utilization of parenteral substrate.

OBJECTIVE

We sought to analyze the relation between a patient's metabolic state and their nutritional intake, substrate utilization, and nitrogen balance (NB) in mechanically ventilated, critically ill children receiving parenteral nutrition.

DESIGN

This was a cross-sectional study in which resting energy expenditure (REE) and NB were measured and substrate utilization and the metabolic index (MI) ratio (REE/expected energy requirements) were calculated.

RESULTS

Thirty-three children (mean age: 5 y) participated. Their average REE was 0.23 +/- 0.10 MJ x kg(-1) x d(-1) and their average MI was 1.2 +/- 0.5. Mean energy intake, protein intake, and NB were 0.25 +/- 0.14 MJ x kg(-1) x d(-1), 2.1 +/- 1 g x kg(-1) x d(-1), and -89 +/- 166 mg x kg(-1) x d(-1), respectively. Patients with an MI >1.1 (n = 19) had a higher fat oxidation than did patients with an MI <1.1 (n = 14; P < 0.05). Patients with lipogenesis (n = 13) had a higher carbohydrate intake than did patients without lipogenesis (n = 20; P < 0.05). Patients with a positive NB (n = 12) had a higher protein intake than did patients with a negative NB (n = 21; P < 0.001) and lower protein oxidation (P < 0.01).

CONCLUSIONS

Critically ill children are hypermetabolic and in negative NB. In this population, fat is used preferentially for oxidation and carbohydrate is utilized poorly. A high carbohydrate intake was associated with lipogenesis and less fat oxidation, a negative NB was associated with high oxidation rates for protein, and a high protein intake was associated with a positive NB.

The effect of graded intake of glycyl-L-tyrosine on phenylalanine and tyrosine metabolism in parenterally fed neonates with an estimation of tyrosine requirement

Although tyrosine is considered indispensable during the neonatal period, its poor solubility has limited its inclusion in parenteral amino acid solutions to less than 1% of total amino acids. Dipeptides of tyrosine are highly soluble, have been shown to be well used and safe in animal models and humans, and, therefore, may be used as an effective means of providing tyrosine in the parenterally fed neonate. The goal of the present study was to determine the tyrosine requirement of the parenterally fed neonate receiving graded intakes of glycyl-L-tyrosine as a source of tyrosine. Thirteen infants receiving adequate energy (340 +/- 38 kJ. kg(-1).d(-1)) and protein (2.4 +/- 0.4 g.kg(-1).d(-1)) were randomized to receive parenteral nutrition with one of five graded levels of glycyl-L-tyrosine. The mean requirement and safe level of intake were estimated using a 1-(13)C-phenylalanine tracer and linear regression cross-over analysis that identified a break point in the response of label appearance in breath CO(2) (F(13)CO(2)) and phenylalanine oxidation to graded tyrosine intake. Based on the mean estimates of whole-body phenylalanine oxidation, the tyrosine mean requirement and safe level of intake were found to be 74 mg.kg(-1). d(-1) and 94 mg.kg(-1).d(-1), respectively. This represents 3.1 and 3.9% of total amino acids, respectively, considerably higher than levels found in present commercially available pediatric amino acid solutions. These data raise concern regarding the adequacy of aromatic amino acid intake in the parenterally fed neonate.

Phenylalanine and tyrosine metabolism in neonates receiving parenteral nutrition differing in pattern of amino acids

Tyrosine is considered to be an indispensable dietary amino acid in the neonate, yet achieving adequate parenteral tyrosine intake is difficult due to its poor solubility. Increasing the supply of phenylalanine is the most common means of compensating for low tyrosine levels. Unfortunately, plasma phenylalanine concentrations are sometimes elevated in infants receiving high phenylalanine intake. This led us to study the phenylalanine and tyrosine metabolism in 16 neonates randomized to receive total parenteral nutrition with either a high or a moderate phenylalanine-containing amino acid solution. A primed, 24-h continuous stable isotope infusion of L-[1-13C]phenylalanine and L-[3,3-2H2]tyrosine was given to enable the measurement of phenylalanine and tyrosine kinetics. Results demonstrated that 1) phenylalanine hydroxylation was significantly greater in infants receiving high phenylalanine, 2) phenylalanine oxidation and percent dose oxidized was also significantly greater in infants receiving high phenylalanine, 3) apparent phenylalanine retention was greater in neonates receiving high phenylalanine, and 4) alternate catabolites of phenylalanine and tyrosine metabolism were significantly greater in infants receiving high phenylalanine compared with moderate phenylalanine. We conclude that neonates respond to increased parenteral phenylalanine intake by increasing their hydroxylation and oxidation rates. The greater oxidation of phenylalanine in infants receiving high phenylalanine in conjunction with the urinary excretion of alternate catabolites of phenylalanine and tyrosine suggests that the high phenylalanine intake may be in excess of needs. However, the lower apparent phenylalanine retention observed in infants receiving moderate phenylalanine suggests that the total aromatic amino acid level of moderate phenylalanine may be deficient for neonatal needs.

Nutritional support in malnourished paediatric patients

An imbalance between a person's energy requirements and his or her dietary protein and caloric supply is the source of protein energy malnutrition (PEM), which compounds the problems of any underlying disease. Malnutrition may occur quite rapidly in critically ill patients, particularly those suffering from sepsis, setting up a vicious cycle with worsening of the PEM. This chapter examines the main consequences of PEM, the means whereby appropriate nutrition may be provided, and risks for severely malnourished paediatric patients in hospital. If the gastrointestinal tract can be used for refeeding, it should be used. When the gastrointestinal tract is unable to meet the protein and energy requirements, parenteral nutrition (PN) is required. PN is efficient but carries a high risk of metabolic complications known as the refeeding syndrome and directly related to the homeostatic changes secondary to severe PEM. Catch-up growth may be achieved by using appropriate nutritional support. Changes in body composition have to be assessed during the course of renutrition.

Iron absorption and red blood cell incorporation in premature infants fed an iron-fortified infant formula

This study was designed to identify differences in red blood cell (RBC) incorporation and iron absorption in premature infants between iron provided in a premature infant formula compared with iron provided as a supplement between feedings. We used a triple stable isotope technique in which 13 infants received 57Fe mixed with Enfamil Premature Formula on d 1 of the study, and 54Fe with a multivitamin supplement between meals on d 2. Two weeks later, blood was drawn for isotope analysis and 58Fe was given i.v. The percentage RBC incorporation of the 54Fe and 57Fe was calculated, and the percent absorption of these tracers was estimated by dividing by the percentage of 58Fe identified in RBCs 14 d after its infusion. We found a small, but significantly greater, percentage of RBC incorporation of the 54Fe given as a supplement compared with the 57Fe given in the formula (9.7 +/- 3.8% versus 7.8 +/- 3.1%, p = 0.02). The RBC 57Fe incorporation was closely correlated with the reticulocyte count (r = 0.80, p = 0.001), but not the serum ferritin or the Hb concentration. Approximately 68% of an i.v. dose of 58Fe was incorporated into RBCs. These findings indicate 1) iron is incorporated well into RBCs from preterm infant formula, with only a small increase in incorporation when given as a supplement, and 2) the reticulocyte count, but not the Hb concentration, is a good measure of RBC iron-incorporating capacity.

Resting energy expenditure and nitrogen balance in critically ill pediatric patients on mechanical ventilation

Nutritional support is important in critically ill patients, with variable energy and nitrogen requirements (e.g., sepsis, trauma, postsurgical state) in this population. This study investigates how age, severity of illness, and mechanical ventilation are related to resting energy expenditure (REE) and nitrogen balance. Nineteen critically ill children (mean age, 8 +/- 6 [SD] y and range 0.4-17.0 y) receiving total parenteral nutrition (TPN) were enrolled. We used indirect calorimetry to measure REE. Expected energy requirements (EER) were obtained from Talbot tables. Pediatric Risk of Mortality (PRISM) and Therapeutic Intervention Scoring System (TISS) score were calculated. Total urinary nitrogen was measured using the Kjeldahl method. PRISM and TISS scores were 9 +/- 5 and 31 +/- 6 points, respectively. REE was 62 +/- 25 kcal.kg-1.d-1, EER was 42 +/- 11 kcal.kg-1. d-1, and caloric intake was 49 +/- 22 kcal.kg-1.d-1. Nitrogen intake was 279 +/- 125 mg.kg-1.d-1, total urinary nitrogen was 324 +/- 133 mg.kg-1.d-1, and nitrogen balance was -120 +/- 153 mg.kg-1.d-1. The protein requirement in this population was approximately 2.8 g.kg-1.d-1. These critically ill children were hypermetabolic, with REE 48% higher (20 kcal.kg-1.d-1) than expected. Nitrogen balance significantly correlated with caloric and protein intake, urinary nitrogen, and age, but not with severity of illness scores or ventilatory parameters.

Long-term growth and development in children after home parental nutrition

Growth and development after the cessation of prolonged parenteral nutrition (PN) has not been fully evaluated. Growth, body composition, and nutritional and developmental status were documented in nine children (five boys, four girls) 2 to 6 years old (mean 4.9 +/- 1.0 years) who had previously received long-term PN (mean 14.6 +/- 11.4 months). PN had been discontinued in all subjects for at least 6 months (mean 3.4 +/- 1.4 years); they were receiving oral feedings only. One subject had a significantly low height-for-age, and another had a low percent ideal body weight; five subjects had low total body fat. Serum vitamin A was low in six subjects. Seventy-two-hour fecal fat analysis was abnormal in two of eight subjects. Abnormal bone mineral density was present in four of nine subjects. Psychomotor development was normal in all nine subjects. Two had functional difficulties in swallowing. One or more abnormalities were present in all nine subjects. These findings suggest that children who require prolonged PN in early life are at risk for abnormalities in growth and nutritional status in later childhood; they require long-term dietary, growth, and nutritional monitoring.

Parenteral and Enteral Nutrition Support Service (NSS): A Multidisciplinary Approach in a Community Hospital

Nutritional support for hospitalized patients is recognized as an important medical therapy. Appropriate nutritional support can promote the patient's maximal response to medications, resistance to sepsis, and recovery from injury. Nutritional support service can be performed by a multidisciplinary team consisting of physicians, registered dietitians, registered nurses, and registered pharmacists. A comprehensive protocol has been developed to guide the nutritional support service. This review summarizes the guidelines of our protocol.

Whole body protein metabolism in children with cancer

Whole body protein synthesis and catabolism were measured using the [ring-2H5]phenylalanine and [1-13C]leucine primed constant infusion technique in 32 paediatric patients with cancer at different stages of treatment. Rates of synthesis (S) and catabolism (C) derived from the [ring-2H5]phenylalanine and [1-13C]leucine models were 4.7 (SD 1.3) (S) and 6.0 (1.5) (C) g/d/kg, and 5.5 (0.8) (S) and 6.8 (1.2) (C) g/d/kg, respectively. These results show that these two tracer techniques give similar results in this study population. Comparison of these values with results previously reported for groups of control children using the [ring-2H5]phenylalanine model (S = 3.69 and 3.93; C = 4.09 and 4.28 g/d/kg) and the [1-13C]leucine model (S = 4.32; C = 4.85 g/d/kg) show that rates of synthesis and catabolism were higher in cancer patients than in controls. Thus whole body protein turnover is increased in children under treatment for cancer. Other indices of metabolism such as plasma amino acids and intermediary metabolites were also measured and showed that, although subjects were in isotopic steady state, there were significant metabolic changes during the course of the primed constant infusions used to measure protein turnover.

Development of pediatric and neonatal parenteral nutrition order forms

The diversity of nutritional needs within the pediatric population makes ordering parenteral nutrition (PN) for infants and children a difficult task for inexperienced clinicians. A well designed PN order form can simplify this task. Standard PN solutions, tables with age-specific nutrient requirements, and guidelines for advancing substrate may improve PN prescriptions and serve as an educational tool. The development of an optimal PN order form for an institution requires consideration of many factors, including the patient population, requirements of the institution, and the needs of the staff and students. One nutrition support team's experience in developing pediatric PN order forms is described.

Intravenous iron administration to very-low-birth-weight newborns receiving total and partial parenteral nutrition

BACKGROUND

Intravenous iron supplements are not routinely administered to very-low-birth-weight newborns receiving total parenteral nutrition because of the possible increased risk of infection and because iron needs may be met with blood transfusions.

METHODS

To assess the benefits of a prudent IV iron supplement (200 to 250 micrograms/kg/d), 26 very-low-birth-weight newborns (birth weight, 1005 +/- 302 g; gestational age, 28 +/- 2.3 weeks; mean +/- SD) were randomly allocated to receive total parenteral nutrition without iron (No-Iron) or with iron supplied as iron dextran (Iron). These newborns were followed at baseline (2 to 3 days after birth) and at weeks 1 to 4 thereafter. At each sampling time, urine samples, fecal samples (rarely), unused total parenteral nutrition solutions, blood products, and a blood sample (1 mL) were collected.

RESULTS

There were no differences between the two groups in anthropometric measurements, hematologic or biochemical parameters, number or amount of blood transfusions (2.3 +/- 1.9), amount of blood removed for diagnostic purposes (44 +/- 16 mL), or number of septic events (n = 16). There was no difference between the groups for the total iron excreted; however, the Iron group retained more iron. Iron balance was negative for all but 10 newborns (No-Iron, 3; Iron, 7) throughout the study.

CONCLUSIONS

A total iron intake of 400 micrograms/kg/d, half of which was provided by IV iron, is not sufficient to maintain iron balance or to meet fetal accretion rates (1000 micrograms/kg/d) in very-low-birth-weight newborns receiving total parenteral nutrition. Furthermore, endogenous iron from blood transfusions does not provide an adequate supply of iron.

Characteristics and consequences of duodenogastric reflux in children on total parenteral nutrition (TPN) for severe gastrointestinal disorders

This study was carried out to determine the frequency and composition (biliary and/or pancreactic) of duodenogastric reflux (DGR) in children with severe gastro-intestinal disorders on total parenteral nutrition (TPN), and to assess its consequences in terms of gastric histology (gastric per endoscopic biopsies) and secretion (acid, pepsin and sialic acid output). Sixteen children (mean age: 20 months) with severe gastro-intestinal disorders requiring TPN (mean duration: 9.5 months) were studied. DGR was demonstrated by measuring gastric choline and trypsin outputs. Serum gastrin levels were measured in all patients. Seven children (44%) had a DGR, with a significant increase in choline output (p < 0.02). Trypsin output was elevated in one patient only. Exudative gastritis and increased sialic acid output occurred in the presence and in the absence of DGR. DGR did not alter the basal acid and pepsin secretions. The serum gastrin levels were normal except in one case. These results show that DGR occurs frequently in children suffering from severe gastro-intestinal disorders on TPN, that it is mainly of biliary origin and that exudative gastritis is very frequent but not correlated with DGR. It suggests that DGR causes little injury in children on TPN, perhaps because of their decreased pancreatic secretion.

The injured child. An approach to care

Injury is the leading cause of childhood death and disability in this country and has been for over a decade. Examination of the current injury statistics clearly demonstrates the failure of our present prevention strategies. Unless definitive steps are undertaken to initiate a comprehensive national injury prevention program, this tragic impact upon children will continue. To ensure that optimal care for injured children is provided, several criteria must be met. Seriously injured children require skillful assessment by clinicians experienced in pediatric trauma and rapid evacuation to a regional pediatric trauma center when appropriate. Their care is best provided by a multidisciplinary team including intensivists, surgeons, and rehabilitation specialists, all thoroughly familiar with the types of injuries children sustain. In the ICU, careful monitoring of circulatory, respiratory, renal, and neurologic status combined with early intervention for physiologic derangements maximizes the injured child's chances for recovery. Finally, it is important to understand that care for the injured child spans a continuum beginning with prevention, continuing through acute care, and ending only after rehabilitation and reintegration into the community is complete, and that each component is no less important than another. Only through these efforts can the loss of our nation's most precious resource be avoided.

Use of cyclic parenteral nutrition in infants less than 6 months of age

Cyclic parenteral nutrition is the technique of infusing the intravenous solution in less than 24 hours, during a portion of the day or night, allowing the patient freedom from the intravenous tubing and pump apparatus. In addition, adverse effects of long-term parenteral therapy, such as liver complications, were reported to be decreased with the use of cyclic parenteral nutrition in adult patients. Literature on the method and effects of cycling in young infants is minimal. This report describes cyclic parenteral nutrition use with guidelines for cycling and the potential beneficial metabolic effects in 10 infants less than 6 months of age who required long-term parenteral nutrition support. Diagnosis, gestational age, length of time on parenteral nutrition, macronutrient intake, growth, and biochemical parameters for the patients are presented. Overall, cyclic parenteral nutrition was well tolerated without clinical symptoms of hypoglycemia, elevated capillary blood glucose concentrations, or abnormal urine glucose levels. The direct bilirubin concentrations showed a decrease or stabilization after cycling was initiated in eight of 10 patients.

Nutrition considerations in the neonatal extracorporeal life support patient

Extracorporeal life support (ECLS) is a type of heart-lung bypass commonly used to support neonates with life-threatening respiratory or cardiac failure. These patients are among the most critically ill patients in the neonatal intensive care unit and are at significant nutritional risk. Unfortunately, there is a paucity of literature regarding guidelines for nutrition support of the neonatal ECLS patient. The purpose of this article is to provide an overview of the indications, techniques, and complications of ECLS and to address the approach to nutrition support of these patients. Emphasis will be placed on issues unique to the neonatal ECLS patient.

Iron overload in children receiving prolonged parenteral nutrition

This study was carried out to evaluate the iron status of 30 children aged 1 to 18 years who had been receiving total parenteral nutrition (TPN) for an average of 43 months with iron intakes of 100 micrograms/kg per day. Iron status was assessed by assaying the serum iron and ferritin levels and the transferrin saturation coefficient as a function of iron intake. Liver biopsy specimens were taken from 13 children. Twelve children had serum ferritin levels greater than 300 ng/ml, and 8 had levels greater than 800 ng/ml. The serum ferritin level and the transferrin saturation coefficient were positively correlated (r = 0.81; p < 0.01). The serum ferritin level was positively correlated with TPN duration and with the total iron intake (r = 0.68; p < 0.01). Of the 13 liver biopsy specimens, six showed signs of iron deposition. We conclude that there is a risk of iron overload in children receiving 100 micrograms iron per kilogram of body weight per day by TPN, indicating that intake should be reduced.

Nitrogen balance in patients treated with extracorporeal membrane oxygenation

Extracorporeal membrane oxygenation (ECMO) is a commonly used technique in the management of newborn respiratory failure. However, few studies have addressed the optimal nutritional support of these critically ill neonates. Eleven newborns undergoing ECMO for respiratory failure were studied at various levels of intravenous caloric and nitrogen intake, using nitrogen balance techniques, to assess optimal nutritional support necessary to achieve positive nitrogen balance. Nonprotein nitrogen calories > 60 kcal/kg/d, and nitrogen > 240 mg/kg/d were necessary to achieve positive nitrogen balance, while maximum positive balance was seen with nitrogen intake > 400 mg/kg/d. These data suggest that newborns treated with ECMO can achieve positive nitrogen balance with modest amounts of caloric and nitrogen intake.

Intestinal absorption of immunologically intact macromolecules in germfree colostrum-deprived piglets maintained on total parenteral nutrition

We have compared the neonatal absorption of anti-bovine gamma-globulin (BGG) antibody supplied in colostrum or saline in three groups of piglets born and maintained under different environmental conditions to determine the effect of these conditions on the cessation of intestinal absorption of macromolecules (anti-BGG antibody), termed "closure." An enzyme-linked immunosorbent assay was used to estimate the concentration of anti-BGG antibody in sera from each group of piglets. Three stages of macromolecular absorption through the piglet's intestine could be detected. The first stage is a nonselective massive absorption of macromolecules (in milligram levels) that lasts up to 3 days in germfree (GF) colostrum-deprived or conventional colostrum-fed piglets but up to 5 days in GF piglets maintained on total parenteral nutrition. In this stage, absorption was significantly (r = .05) higher in piglets fed anti-BGG serum with colostrum than in piglets fed anti-BGG serum without colostrum on GF day 0 (31.28% vs 15.59%) and GF-total parenteral nutrition day 3 (3.08% vs 0.11%). Thus, whenever there was the ability to absorb a massive amount of macromolecules, the sow colostrum had an enhancing affect. Although there was a minor effect of environmental or orally received stimuli in delaying closure, absorption of macromolecules decreased in all piglets maintained either parenterally or enterally after day 3. Thus, intestinal closure to massive absorption of macromolecules in piglets is primarily time (age)-dependent. The second stage is a selective absorption of immunoglobulins in much smaller quantities (microgram levels), inasmuch as absorption of 0.02% to 0.1% was determined in all 5-day-old piglets.(ABSTRACT TRUNCATED AT 250 WORDS)

Parenteral nutrition in the management of severe protracted diarrhea

Seventeen children aged 3 weeks to 19 months with severe Protracted Diarrhea (PD), and who were deteriorating on our standard management protocol (including special diets) were given Parenteral Nutrition (PN) for 4 to 19 days with crystalline aminoacid solution (Vamin N) in 10% dextrose and lipid emulsion (Intralipid 10%). Peripheral lines were used in majority (84%). Enteral feeds were started early and rebuilt as per tolerance. The mean daily protein and caloric intake achieved by hyperalimentation was 2.2 +/- 0.7 g/kg and 106 +/- 41 K cal/kg respectively. Diarrheal control and improvement in nutritional status was achieved in all but 4 who died (2 of refractory diarrhea and 2 of sepsis, 1 of which was probably PN related). Other PN related, treatable complications included thrombophlebitis (11.8%), sepsis (17.6%), and metabolic imbalance (17.6%). PN solutions and accessories alone cost an approximate average of Rs. 280/day, with extras for biochemical monitoring (Rs. 70/day) and special nursing (Rs. 200/day). Only 5 of the 13 survivors had a significant relapse of PD, within 5 to 80 days of discharge, necessitating further PN in 2. There were no further deaths. PN was therefore, found to be of life saving value in 13 of 17 children with severe protracted diarrhea and therefore, must be available in specialised units caring for such children.

Glucose versus glucose-fat mixture in the course of total parenteral nutrition: effects on substrate utilisation and energy metabolism in malnourished children

Energy substrate utilisation was evaluated over 21 days in two groups of malnourished children on total parenteral nutrition (TPN). Non-protein energy was infused as glucose (Group A; n = 7) or as a glucose/fat (1:1 v/v) mixture (Group B; n = 10). Results indicated that: 1) net glucose oxidation was related to glucose intake; 2) glucose storage was elevated in group A; 3) net fat synthesis occurred earlier in group B together with constant net fat oxidation which was inversely related to glucose intake (r = -0.89, p < 0.001); 4) lipogenesis from glucose occurred only when glucose intake exceeded 19.3g/kg/d; 5) energy expenditure increased by 36% (group A) and 18% (group B) during renutrition; 6) 73% and 82% of the energy administered in excess of energy required was stored in group A and B respectively. Hence, glucose/fat infusion appears to be more energy-efficient than glucose-alone in TPN of malnourished children.

Electrophysiologic and histological monitoring of MHC-matched and mismatched canine intestinal allografts

Intestinal transplantation (ITx) has potential applications for the treatment of short-bowel syndrome (SBS). A major obstacle to its clinical use is rejection, which may partly be overcome by major histocompatibility complex (MHC) matching. At present, it is impossible to predict accurately the early onset of rejection. The aim of this study was to assess the value of in vivo measurements of transepithelial potential difference (PD) for the determination of rejection in MHC-matched and -mismatched canine ITx. A heterotopic ITx was performed in MHC tissue-typed Beagle dogs. Two ileostomies were created for PD monitoring and histology. Via one ileostomy, a well-defined segment of the IT, was isolated by a double balloon catheter and the intraluminal PD was measured in reference to a subcutaneous electrode. The PD responses during perfusion of a theophylline solution (crypt cell stimulation, PD theophylline) and during perfusion of a glucose solution (villus cell stimulation, PD glucose) were assessed. The results of in vivo PD measurements were compared with simultaneously obtained histology specimens. Four groups of dogs were studied: group 1 (controls, n = 10) ileal autotransplants; group 2 (n = 6) ileal allotransplants, fully mismatched; group 3 (n = 3) ileal allotransplants, 1 haplotype identical; and group 4 (n = 5), ileal allotransplants, fully matched. No immunosuppression was given. All dogs of group 1 survived indefinitely and both PD and histology showed no abnormalities. In group 2, 3, and 4 the onset of histological changes related to rejection corresponded well with decreased PD responses.(ABSTRACT TRUNCATED AT 250 WORDS)

Energy expenditure and substrate utilization in the course of renutrition of malnourished children

Energy expenditure (EE) and substrate utilization in the course of renutrition of malnourished children is not well understood in children receiving total parenteral nutrition (TPN). The aim of this study was to evaluate, during protein-glucose renutrition, EE and substrate utilization and the relationship between EE and growth and/or protein metabolism. Seven malnourished children were studied during the first 3 weeks of TPN. Weight-for-height = 81.4 +/- 8.0%, with an initial weight of 4.5 +/- 3.3 kg. Caloric support was progressively increased according to a preestablished protocol. Every 7 days the following were determined: (1) EE at 3 different 3-hour intervals per day using an open circuit indirect calorimetric system, (2) anthropometrically defined fat free mass (FFM), and (3) 24-hour urinary 3-methylhistidine (3-M-His) and protein balance. Compared to initial values, EE increased 13% at day 7 and 36% at day 14. A negative relationship was found between the amount of perfused glucose and lipid utilization (r = -0.82; p less than 0.0001). EE per kilogram of total body FFM changes during renutrition were more than EE changes per kilogram of total body weight. There was a relationship between EE and weight gain (r = 0.62; p less than 0.005) and a positive relationship between EE and protein gain (r = 0.48; p = 0.012) and 3-M-His excretion (r = 0.51; p less than 0.026).(ABSTRACT TRUNCATED AT 250 WORDS)

A usage evaluation of total parenteral nutrition in pediatric patients

Records of 20 consecutive pediatric patients receiving total parenteral nutrition over a 1-month period were reviewed for appropriateness of nutritional assessment and management. Each patient was monitored until total parenteral nutrition was discontinued or for a maximum of 2 weeks. A total of 124 therapy days were reviewed. Results demonstrated that only 35% of these patients had a nutritional assessment performed prior to initiation of therapy, and only 65% had nutritional goals determined. Nutritional goals were defined as patient-specific goals for fluid volume (FV), calories, protein, and fat emulsion. Analysis of data demonstrated that goals for FV were met on 62% of therapy days. Of the days on which FV goals were met, goals for calories, protein, and fat emulsion were met on 54%, 59%, and 51% of therapy days, respectively. Baseline serum triglyceride levels were measured in one of 20 patients. Serial laboratory monitoring was adequate, with the exception of hepatic enzymes and serum triglycerides, which were measured in 14 and 9 patients, respectively. Recommendations for pediatric parenteral nutrition therapy are discussed, as well as methods to implement these recommendations.

Three-in-one parenteral nutrition: a safe and economical method of nutritional support for infants

The medical records of 20 infants under 1 year of age who received parenteral nutrition (PN) for a minimum of 1 week were reviewed. Patients were divided into two groups based on the method of PN administration. One group received PN by the traditional two-plus-one method where lipid emulsion is given separately from the dextrose-amino acid mixture. The second group received PN by the three-in-one method where lipid emulsion is admixed with the dextrose and amino acids. There were no statistically significant differences between the two groups in the amount of calories, lipid, dextrose, protein, calcium, and phosphorus received per kg of body weight. Average daily weight gain was not statistically different, and no obvious trends were noted in serum biochemical parameters between the two groups. Average total PN days for the groups (13 +/- 7 days for the two-plus-one group vs 39 +/- 35 days for the three-in-one group) were significantly different (p less than 0.05). A cost comparison of the two methods of PN administration indicated that the two-plus-one method costs our hospital $11.78 more per day than the three-in-one solution. We conclude that the three-in-one method of PN administration is safe, efficacious, and cost effective for infants under 1 year of age.

Intravenous fat emulsion (intralipid) delays gastric emptying, but does not cause gastroesophageal reflux in healthy volunteers

The impact of overnight intravenous lipid emulsion (ILE) infusion on upper gastrointestinal tract physiology was assessed in 10 healthy volunteers. No changes in lower esophageal sphincter pressure (before infusion: 28 +/- 4 mm Hg; after infusion 20.5 +/- 3; p:NS), plasma concentrations of gastrointestinal hormones (gastrin: preprandial before/after lipids: 14 +/- 2.1/13 +/- 1.4 pM; postprandial before/after lipids: 28 +/- 2.7/30 +/- 3.4 pM, CCK: preprandial before/after lipids: 69 +/- 10/64 +/- 10 pM; postprandial before/after lipids: 96 +/- 11/95 +/- 12 pM; neurotensin: levels less than 6 pM in all samples; somatostatin levels undetectable in all samples) nor on pathologic gastroesophageal reflux episodes (% of time of pH less than 4, before/after lipids: 0.6 +/- 0.4/0.15 +/- 0.09), were found (p = NS). In contrast, technetium gastric emptying studies showed a significant delay when comparing pre- and post-lipid infusion values (37 +/- 4/54 +/- 4%) (p greater than 0.005). The mechanism of this effect remains unexplained.

Measured energy expenditure in critically ill infants and young children

Technological limitations have impeded accurate energy expenditure assessment in critically ill infants and young children. Instead, a predicted energy expenditure (PEE) is derived based on weight, heat loss, activity, growth requirements, and degree of stress. This study compared actual measured energy expenditure (MEE) with conventional predicted values in 20 critically ill infants and children using a validated metabolic cart designed for use in this age group. All patients were studied either within 4 days of major surgery or during an acute disease process necessitating intensive care. All were severely stressed clinically and were studied while mechanically ventilated in a temperature-controlled environment. The study interval ranged from 1 to 12 hr and averaged 4 hr after a stabilization period of 30 min. The mean MEE was significantly lower than the mean PEE (52.2 +/- 16 kcal/kg/day vs 101.8 +/- 17 kcal/kg/day, P less than 0.001) with a mean MEE/PEE of 52.6 +/- 17% (range 26 to 92%). In a subgroup of 7 paralyzed patients, the mean MEE was significantly lower than in the 13 nonparalyzed patients when compared with PEE and predicted basal metabolic rate (PBMR). The coefficient of variance, conventionally recognized to be approximately 15% for PEE, averaged 6.35% for MEE in this study. These data indicate that if PEE is used as the sole guide for caloric repletion in the stressed infant or child, these patients will be substantially overfed.

An algorithm for pediatric enteral alimentation

Many of the metabolic and gastrointestinal complications that occur when patients receive tube feedings result from improper selection or administration of the formula. An algorithm, available tables of formula composition, and adequate flowsheets for recording clinical information that can be adapted to individual institutions will provide simple and practical guidelines for the selection, administration, and management of enteral feeding programs in pediatric patients.