Pediatric parenteral nutrition: putting the microscope on macronutrients and micronutrients

Dietary Micronutrients from Zygote to Senility: Updated Review of Minerals' Role and Orchestration in Human Nutrition throughout Life Cycle with Sex Differences

Micronutrients such as selenium, fluoride, zinc, iron, and manganese are minerals that are crucial for many body homeostatic processes supplied at low levels. The importance of these micronutrients starts early in the human life cycle and continues across its different stages. Several studies have emphasized the critical role of a well-balanced micronutrient intake. However, the majority of studies looked into or examined such issues in relation to a specific element or life stage, with the majority merely reporting the effect of either excess or deficiency. Herein, in this review, we will look in depth at the orchestration of the main element requirements across the human life cycle beginning from fertility and pregnancy, passing through infancy, childhood, adolescence, and reaching adulthood and senility, with insight on the interactions among them and underlying action mechanisms. Emphasis is given towards approaches to the role of the different minerals in the life cycle, associated symptoms for under- or overdoses, and typical management for each element, with future perspectives. The effect of sex is also discussed for each micronutrient for each life stage as literature suffice to highlight the different daily requirements and or effects.

Evaluating the risk of manganese-induced neurotoxicity of parenteral nutrition: review of the current literature

INTRODUCTION

Several diseases and clinical conditions can affect enteral nutrition and adequate gastrointestinal uptake. In this respect, parenteral nutrition (PN) is necessary for the provision of deficient trace elements. However, some essential elements, such as manganese (Mn) may be toxic to children and adults when parenterally administered in excess, leading to toxic, especially neurotoxic effects.

AREAS COVERED

Here, we briefly provide an overview on Mn, addressing its sources of exposure, the role of Mn in the etiology of neurodegenerative diseases, and focusing on potential mechanisms associated with Mn-induced neurotoxicity. In addition, we discuss the potential consequences of overexposure to Mn inherent to PN.

EXPERT OPINION

In this critical review, we suggest that additional research is required to safely set Mn levels in PN, and that eliminating Mn as an additive should be considered by physicians and nutritionists on a case by case basis in the meantime to avoid the greater risk of neurotoxicity by its presence. There is a need to better define clinical biomarkers for Mn toxicity by PN, as well as identify new effective agents to treat Mn-neurotoxicity. Moreover, we highlight the importance of the development of new guidelines and practice safeguards to protect patients from excessive Mn exposure and neurotoxicity upon PN administration.

Bone Mineral Composition Among Long-Term Parenteral Nutrition Patients: Postmortem Assessment of Calcium, Phosphorus, Magnesium, and Select Trace Elements

BACKGROUND

Patients receiving long-term parenteral nutrition (PN) treatment are at risk of developing metabolic bone diseases (MBDs). The bone compartment serves as a repository for a range of metal(loid)s that are administered intravenously to patients via PN solutions. Thus, the mineral composition of patient bones may be linked to the development of MBDs in this group.

METHODS

We measured 12 elements in bone samples obtained post mortem from 7 long-term (2-21 years) PN patients and 18 control bones obtained from hip/knee replacement surgery. The samples were cleaned, digested, and subsequently analyzed using a method based on inductively coupled plasma tandem mass spectrometry.

RESULTS

Compared with the control group, bones obtained from PN patients were significantly (P < 0.05) depleted in calcium (Ca), phosphorus (P), magnesium (Mg), chromium, and strontium and enriched in manganese (Mn), zinc, barium, cadmium (Cd), and uranium (U). No differences were observed for cobalt or lead.

CONCLUSIONS

Depletion of major components of bone mineral (Ca, P, and Mg) and enrichment in known toxicants (Cd, Mn, U) are concerns for PN patients.

Increased Needs for Copper in Parenteral Nutrition for Children in the Neonatal Intensive Care Unit With an Ostomy

BACKGROUND

Copper (Cu) is an essential trace element, with deficiency causing anemia, neutropenia, and other abnormalities. Cu is mainly absorbed in the small intestine. Patients with intestinal failure or jejunostomy have increased Cu losses and require additional Cu supplementation in parenteral nutrition (PN). The American Society for Clinical Nutrition standards for trace element recommendations in PN, including Cu, were created in 1988, and the American Society for Parenteral and Enteral Nutrition currently follows the same recommendations.

METHODS

Patients admitted to the neonatal intensive care unit for surgical intervention resulting in an ostomy (ileal or jejunal) were included in this retrospective study. Patients received PN support with Cu dosed individually, rather than in a multi-trace element package. Cu and ostomy output were analyzed daily. Serum Cu was obtained 2 months postsurgical intervention.

RESULTS

Out of the 7 patients enrolled, 71% had low serum Cu. Weekly mean Cu intake for all 7 patients ranged from 5.3 to 154.8 μg/kg/day from enteral and parenteral sources, with individual mean weekly Cu intake ranging from 18.9 to 74.4 μg/kg/day from surgical intervention to 2 months post-surgery. Patients' weekly ostomy outputs ranged from 0 mL/kg/day to 77.2 mL/kg/day, with individual mean weekly output ranging from 3.7 to 41.6 mL/kg/day.

CONCLUSION

Providing 20 μg/kg/day of Cu in PN to neonates with ostomies is insufficient to prevent Cu deficiency. Further studies are warranted to determine an optimal dosage of parenteral Cu to prevent Cu deficiency.

[Levels of blood free carnitine in preterm infants with different gestational ages and birth weights]

OBJECTIVE

To examine blood concentrations of free carnitine (FC) in preterm infants with different gestational ages (GA) and birth weights (BW).

METHODS

A total of 3 368 preterm infants were enrolled as subjects. According to GA, they were divided into extremely preterm birth (EPTB) group (GA <28 weeks; n=39), very preterm birth (VPTB) group (28 ≤GA <32 weeks; n=405), moderately preterm birth (MPTB) group (32 ≤GA <34 weeks; n=507), and late preterm birth (LPTB) group (34 ≤GA <37 weeks; n=2 417); according to BW, they were divided into extremely low birth weight (ELBW) group (BW <1 000 g; n=36), very low birth weight (VLBW) group (1 000 g ≤BW <1 500 g; n=387), low birth weight (LBW) group (1 500 g ≤BW <2 500 g; n=1 873), and normal birth weight (NBW) group (2 500 g ≤ BW <4 000 g; n=1 072). Blood concentrations of FC were measured between 72 hours and 7 days after birth.

RESULTS

The EPTB and VPTB groups had significantly higher FC concentrations than the MPTB and LPTB groups (P<0.05), and the MPTB group had significantly higher FC concentrations than the LPTB group (P<0.05). The lower limit of the 95% medical reference range of FC increased with the reduction in GA. The ELBW and VLBW groups had significantly higher FC concentrations than the LBW and NBW groups (P<0.05). The LBW group had significantly higher FC concentrations than the NBW group (P<0.05). The lower limit of the 95% medical reference range of FC increased with the reduction in BW.

CONCLUSIONS

There is a significant increase in blood FC concentrations in very/extremely preterm infants and very/extremely low birth weight infants, and tend to decrease with the increases in GA and BW.

Monitoring of long-term parenteral nutrition in children with intestinal failure

Pediatric intestinal failure (IF) is a rare and complex condition associated with significant morbidity and mortality. It is defined as the reduction of gut mass or function below the minimal needed for absorption of nutrients and fluid to sustain life and growth. Since the advent of specialized multidisciplinary intestinal rehabilitation centers, IF management has considerably evolved in the last years, but serious complications of long-term parenteral nutrition (PN) can occur. Main complications include intestinal failure-associated liver disease, growth failure, body composition imbalance, central venous access complications, micronutrient deficiencies and toxicities, metabolic bone disease, small intestinal bacterial overgrowth, and renal disease. With improvement in survival rates of patients over the last 20 years, emphasis should be on limiting IF-related comorbidities and improving quality of life. Close monitoring is pivotal to ensuring quality of care of these patients. The care of children with chronic IF should involve a comprehensive monitoring plan with flexibility for individualization according to specific patient needs. Monitoring of children on long-term PN varies significantly across units and is mainly based on experience, although few guidelines exist. This narrative review summarizes the current knowledge and practices related to monitoring of children with IF. The authors also share their 20-year experience at the Royal Children's Hospital in Melbourne Australia on this topic.

The Role of Parenteral Lipids in the Development of Hepatic Dysfunction and Hepatic Steatosis in a Mouse Model of Total Parenteral Nutrition

Parenteral nutrition-associated liver disease, a common and life-threating complication among people who require long-term parenteral nutrition, has been associated with abnormal liver function, cholestasis, steatosis and fibrosis. Intravenous soybean lipids may be associated with the development of liver disease. We therefore examined whether different doses of parenteral lipids would affect the development of liver disease, and further investigated the possible pathogenesis of it. C57BL/6J mice with a central catheter placed in the right jugular vein were divided into three groups. The control group received normal mouse chow with intravenous normal saline; The lipids group received parenteral nutrition solution (0.14 g lipids per day); the H-lipids group received parenteral nutrition solution with twice the amount of lipids (0.3 g lipids per day). Changes in body weight, serum biochemical parameters, liver histology and farnesoid X receptor gene expression in the liver were assessed. The values of serum direct bilirubin, total bilirubin and cholesterol were markedly increased in the H-lipids group at day 7. The predominant histologic finding in the H-lipids group was steatosis, and the steatosis score in the H-lipids group was much higher than in the other two groups at either day 5 or day 7. Hepatic expression of farnesoid X receptor mRNA decreased after 7 d of parenteral nutrition. High doses of parenteral lipids are more likely to develop liver disease in a mouse model of parenteral nutrition. Farnesoid X receptor may play a key role in the development of parenteral nutrition-associated liver disease.

Trace Element Provision in Parenteral Nutrition in Children: One Size Does Not Fit All

Routine administration of trace elements is recognised as a standard of care in children requiring parenteral nutrition. However, there is a lack of global consensus regarding trace elements provision and dosing in pediatric parenteral nutrition. This review provides an overview of available evidence regarding trace elements supply and posology in parenteral nutrition in neonates and children. Trace elements provision in children should be tailored to the weight and clinical condition of the child with emphasis on those at risk of toxicity or deficiency. Based on current evidence, there is a need to review the formulation of commercial solutions that contain multiple-trace elements and to enable individual trace elements additives to be available for specific indications. Literature supports the removal of chromium provision whereas manganese and molybdenum supplementation are debated. Preterm neonates may have higher parenteral requirements in iodine, selenium and copper than previously recommended. There is growing support for the routine provision of iron in long-term parenteral nutrition. Further studies on trace elements contamination of parenteral nutrition solutions are needed for a range of trace elements.

A safe and efficacious preventive strategy in the high-risk surgical neonate: cycled total parenteral nutrition

INTRODUCTION

Hepatic dysfunction in patients reliant on total parenteral nutrition (TPN) may benefit from cycled TPN. A concern for neonatal hypoglycemia has limited the use of cycled TPN in neonates less than 1 week of age. We sought to determine both the safety and efficacy of cycled TPN in surgical neonates less than 1 week of age.

METHODS

A retrospective chart review was conducted on surgical neonates placed on prophylactic and therapeutic cycled TPN from January 2013 to March 2016. Specific emphasis was placed on identifying incidence of direct hyperbilirubinemia and hypoglycemic episodes.

RESULTS

Fourteen neonates were placed on cycled TPN; 8 were prophylactically cycled and 6 were therapeutically cycled. Median gestational age was 36 weeks (34, 37). Sixty-four percent (n = 9) had gastroschisis. There was no difference between the prophylactic and therapeutic groups in incidence of hyperbilirubinemia > 2 mg/dL (3 (37%) vs 5 (83%), p = 0.08) or the length of time to development of hyperbilirubinemia [24 days (4, 26) vs 27 days (25, 67), p = 0.17]. Time on cycling was similar though patients who were prophylactically cycled had a shorter overall time on TPN. Three (21%) infants had documented hypoglycemia, but only one infant became clinically symptomatic.

CONCLUSION

Prophylactic TPN cycling is a safe and efficacious nutritional management strategy in surgical neonates less than 1 week of age with low rates of hypoglycemia and a shorter total course of TPN; however, hepatic dysfunction did not appear to be improved compared to therapeutic cycling.

Selenium supplementation in pediatric patients using parenteral nutrition: Is it time to do something?

OBJECTIVE

To analyze the nutritional status of selenium and verify the effect of its supplementation in pediatric patients during 14 days of parenteral nutrition (PN).

METHOD

This is a series of cases with patients followed for two weeks while using PN. Data collection was performed at the beginning (T0), in the 7th (T1) and 14th days of PN (T2). The supplemented group received 2 µg/kg/day of selenous acid. Weight and height were measured for nutritional status assessment. Tests requested: plasma selenium, albumin, pre-albumin, C-reactive protein (CRP), total cholesterol and HDL-cholesterol.

RESULTS

Fourteen (14) patients with inflammatory process and with low or very low weight for their ages were evaluated. In both groups (with and without supplementation), all patients had low selenium levels. Median plasma selenium concentrations were 17.4 µg/L (T0), 23.0 µg/L (T1) and 20.7 µg/L (T2). Increase and reduction of selenium occurred both in patients with high CRP and in those presenting normalization of this parameter.

CONCLUSION

Lower plasma selenium levels have been detected since the start of the research and supplementation (2 µg/kg/day of selenous acid) was not to enough to approach the reference values.

Survey of Nutrition Management Practices in Centers for Pediatric Intestinal Rehabilitation

BACKGROUND

Nutrition management of pediatric intestinal failure (IF) requires interdisciplinary coordination of parenteral nutrition (PN) and enteral nutrition (EN) support. Nutrition strategies used by specialists in pediatric intestinal rehabilitation to promote gut adaptation and manage complications have not been previously summarized.

METHODS

A practice survey was distributed to members of the dietitian subgroup of the American Society for Parenteral and Enteral Nutrition Pediatric Intestinal Failure Section. The survey included 24 open-ended questions related to PN and enteral feeding strategies, nutrition management of PN-associated liver disease, and laboratory monitoring.

RESULTS

Dietitians from 14 centers completed the survey. Management components for patients at risk for cholestasis were consistent and included fat minimization, trace element modification, avoiding PN overfeeding, and providing EN. Parenteral amino acid solutions designed for infants/young children are used in patients <1 or 2 years of age. Trace minerals are dosed individually in 10 of 14 centers. Eleven centers prescribe a continuous infusion of breast milk or elemental formula 1-2 weeks after resection while 3 centers determine the formula type by the extent of resection. Most (86%) centers do not have a protocol for initiating oral/motor therapy. Laboratory panel composition varied widely by center. The selection and frequency of use depended on clinical variables, including cholestatic status, exclusive vs partial PN dependence, postrepletion verification vs routine monitoring, intestinal anatomy, and acuity of care.

CONCLUSION

EN and PN management strategies are relatively consistent among U.S. centers. Collaborative initiatives are necessary to define better practices and establish laboratory monitoring guidelines.

Reduced risk of pulmonary emboli in children treated with long-term parenteral nutrition

BACKGROUND & AIMS

Pulmonary embolism (PE) is a complication of parenteral nutrition (PN) with a prevalence of 35% in children. In 2003 new intravenous lipid emulsions (ILEs) with MCT, olive and/or fish oil in addition to soybean oil were introduced. The aim was to compare the incidence of PE before and after introduction.

METHODS

327 surveillance ventilation-perfusion (V/Q) scintigraphies from 68 children aged 0.3-15 years, treated with PN from 1993 to 2010, were retrospectively reviewed. Rate of PE/1000 central venous catheter (CVC) days, number of children with PE pre- and post-introduction of ILEs were compared. Multivariate analyses were performed for risk factors.

RESULTS

Twenty-two (32%) children (19/42 before 2003 and 3/26 after 2003, p = 0.007) had at least one episode of PE. Thirty seven (11%) episodes of PE were detected accounting for a mean of 0.2/1000 CVC days prior to 2003 and 0.05/1000 CVC days after 2003, p = 0.04. Regression analysis indicated that higher content of ILE/infusion (p = 0.045) and frequency of ILE of >3 nights/week were associated with more PE (p = 0.001). New ILEs were associated with lower risk (p = 0.003).

CONCLUSION

With a four-fold fall in incidence with new ILE, PE remains a complication. We recommend 12-18 monthly surveillance with lung perfusion scan and anticoagulants if PE is diagnosed.

Pediatric parenteral nutrition-associated liver disease and cholestasis: Novel advances in pathomechanisms-based prevention and treatment

Parenteral nutrition constitutes a life-saving therapeutic tool in patients unable to ingest/absorb oral or enteral delivered nutrients. Liver function tests abnormalities are a common therapy-related complication, thus configuring the so-called Parenteral Nutrition Associated Liver Disease (PNALD) or cholestasis (PNAC). Although the damage is frequently mild, and resolves after discontinuation of parenteral nutrition, in some cases it progresses into cirrhotic changes, especially in neonates and infants. We present a literature review focusing on the pathogenetic mechanisms-driven prevention and therapies for the cases where parenteral nutrition cannot be discontinued. Ursodeoxycholic acid has been proposed in patients with cholestatic hepatopathy, but its efficacy needs to be better established. Little evidence is available on efficacy of anti-oxidants, antibiotics, probiotics and anti TNFα. Lipid emulsions based on fish oil with a high content of long-chain polyunsaturated fatty acids ω-3 appear effective both in decreasing intrahepatic inflammation and in improving biliary flow. Most recent promising variations such as soybean/MCT/olive/fish oil emulsion [third generation lipid emulsion (SMOFlipid)] are under investigation. In conclusion, we remark the emergence of a number of novel pathomechanisms underlying the severe liver impairment damage (PNALD and PNAC) in patients treated with parenteral nutrition. Only few traditional and innovative therapeutic strategies have hitherto been shown promising.

Impact of the Nationwide Intravenous Selenium Product Shortage on the Development of Selenium Deficiency in Infants Dependent on Long-Term Parenteral Nutrition

BACKGROUND

For patients dependent on parenteral nutrition (PN), selenium must be supplemented intravenously. A nationwide intravenous selenium shortage began in April 2011. The impact of this shortage on PN-dependent infants was evaluated by examining the provision of selenium, development of biochemical deficiency, and costs associated with the shortage.

MATERIALS AND METHODS

This single-center, retrospective study included PN-dependent infants aged ≤1 year who weighed ≤30 kg, received PN for ≥1 month, and had ≥1 serum selenium measurement. The primary outcome was the incidence of biochemical selenium deficiency. Secondary outcomes included severity of biochemical deficiency, clinical manifestations, costs, and relationship between serum selenium levels and selenium dose.

RESULTS

The average selenium dose decreased 2-fold during the shortage (2.1 ± 1.2 µg/kg/d; range, 0.2-4.6 µg/kg/d) versus the nonshortage period (3.8 ± 1 µg/kg/d; range, 2.4-6 µg/kg/d; P < .001). A linear relationship between serum selenium concentration and selenium dose was observed (r(2) = 0.42), with a dose of 6 µg/kg/d expected to result in normal serum levels in most cases. Similar proportions of patients developed biochemical deficiency in both groups: shortage period, 59.1%; nonshortage, 66.7%; P = .13. The severity of biochemical deficiency was similar between groups. A significant increase in incremental cost during the shortage was observed.

CONCLUSION

This is the first study examining the impact of the intravenous selenium shortage on PN-dependent infants. Both groups exhibited similarly high incidences of biochemical selenium deficiency, suggesting higher empiric doses may benefit this population. However, ongoing shortages limit the ability to provide supplementation.

Incidence and Risk Factors of Parenteral Nutrition-Associated Cholestasis in Omani Neonates: Single centre experience

OBJECTIVES

Parenteral nutrition-associated cholestasis (PNAC) is one of the most challenging complications of prolonged parenteral nutrition (PN) in neonates. There is a lack of research investigating its incidence in newborn infants in Oman and the Arab region. Therefore, this study aimed to assess the incidence of PNAC and its risk factors in Omani neonates.

METHODS

This retrospective study took place between January and April 2014. All neonates who received PN for ≥14 days during a four-year period (June 2009 to May 2013) at the neonatal intensive care unit (NICU) in Sultan Qaboos University Hospital, Muscat, Oman, were enrolled.

RESULTS

A total of 1,857 neonates were admitted to the NICU over the study period and 135 neonates (7.3%) received PN for ≥14 days. Determining the incidence of PNAC was only possible in 97 neonates; of these, 38 (39%) had PNAC. The main risk factors associated with PNAC were duration of PN, duration of enteral starvation, gastrointestinal surgeries, blood transfusions and sepsis. Neonates with PNAC had a slightly higher incidence of necrotising enterocolitis in comparison to those without PNAC.

CONCLUSION

This study found a PNAC incidence of 39% in Omani neonates. There were several significant risk factors for PNAC in Omani neonates; however, after logistic regression analysis, only total PN duration remained statistically significant. Preventive strategies should be implemented in NICUs so as to avoid future chronic liver disease in this population.

Glucagon-Like Peptide 2 Improves Cholestasis in Parenteral Nutrition--Associated Liver Disease

BACKGROUND

Parenteral nutrition-associated liver disease (PNALD) remains a significant cause of morbidity and mortality in neonates with intestinal failure. Although glucagon-like peptide-2 (GLP-2) is being advanced as therapy, the effect of GLP-2 treatment on PNALD is unknown. We aim to investigate the effect of exogenous GLP-2 administration on hepatic function in a neonatal piglet model of PNALD.

METHODS

Neonatal piglets (aged 2-6 days) underwent jugular venous catheterization to receive isonitrogenous, isocaloric parenteral nutrition (PN). Piglets were allocated to 2 groups: group 1 (n = 8) received saline while group 2 (n = 7) received GLP-2 (at 11 nmol/kg/d). After 17 days, piglets underwent terminal laparotomy, and bile flow was measured. Liver specimens were analyzed histologically and with immunoperoxidase staining. Age-matched sow-reared control piglets (group 3, n = 8) were used for comparison.

RESULTS

Both groups 1 and 2 receiving PN developed cholestasis relative to sow-reared controls, as evidenced by a decrease in bile flow and increase in serum total bilirubin. However, group 2 had improved bile flow (1.35 vs 0.73 µL/g; P = .02) and diminished bilirubin (38.0 vs 78.5 µmol/L; P = .008) compared with group 1. Group 2 also had lower serum alanine aminotransferase levels, a marker of liver injury. Histologically, the liver specimens in group 1 had marked hepatocyte pigmentation, which was decreased in group 2 specimens.

CONCLUSIONS

The exogenous administration of GLP-2 is associated with the improvement of cholestasis and liver injury. This study introduces a novel role for GLP-2 in improving PNALD in the setting of prolonged PN duration.

Understanding triglyceride levels related to intravenous fat administration

Lipid is an essential macronutrient in parenteral nutrition (PN) support. intravenous (IV) lipid provides essential fatty acids and a concentrated calorie source. Preterm infants are at risk for essential fatty deficiency early in life. Lipid administration is associated with some risks, and there are guidelines for administration to minimize complications. Lipid emulsions in the United States are derived from soybean oil. Outside of the United States, lipid emulsions made from fish oil or combinations of fish, soybean, olive, and medium-chain triglycerides (MCTs) are under investigation for improved tolerance, lower plasma lipid levels, and improved fatty acid profiles, all of which are considered beneficial. Triglyceride levels are an important measurement to assess patient tolerance.

Neonatal and pediatric parenteral nutrition

Parenteral nutrition is one of the most important therapeutic modalities invented in the last several decades. Since its introduction in the 1960s, this modality has saved thousands of lives by providing nutrients parenterally to sustain growth in premature neonates with severe intestinal immaturity and other pediatric patients with intestinal failure, such as a gastrointestinal fistula or short bowel syndrome. Although parenteral nutrition can be a lifesaving treatment, it is not benign. Many complications can result from either short- or long-term usage. This review discusses the nutritional requirements, common complications, medication additives, and special considerations for pediatric patients requiring parenteral nutrition.

Manganese and the brain

Manganese (Mn) is an essential trace metal that is pivotal for normal cell function and metabolism. Its homeostasis is tightly regulated; however, the mechanisms of Mn homeostasis are poorly characterized. While a number of proteins such as the divalent metal transporter 1, the transferrin/transferrin receptor complex, the ZIP family metal transporters ZIP-8 and ZIP-14, the secretory pathway calcium ATPases SPCA1 and SPCA2, ATP13A2, and ferroportin have been suggested to play a role in Mn transport, the degree that each of them contributes to Mn homeostasis has still to be determined. The recent discovery of SLC30A10 as a crucial Mn transporter in humans has shed further light on our understanding of Mn transport across the cell. Although essential, Mn is toxic at high concentrations. Mn neurotoxicity has been attributed to impaired dopaminergic (DAergic), glutamatergic and GABAergic transmission, mitochondrial dysfunction, oxidative stress, and neuroinflammation. As a result of preferential accumulation of Mn in the DAergic cells of the basal ganglia, particularly the globus pallidus, Mn toxicity causes extrapyramidal motor dysfunction. Firstly described as "manganism" in miners during the nineteenth century, this movement disorder resembles Parkinson's disease characterized by hypokinesia and postural instability. To date, a variety of acquired causes of brain Mn accumulation can be distinguished from an autosomal recessively inherited disorder of Mn metabolism caused by mutations in the SLC30A10 gene. Both, acquired and inherited hypermanganesemia, lead to Mn deposition in the basal ganglia associated with pathognomonic magnetic resonance imaging appearances of hyperintense basal ganglia on T1-weighted images. Current treatment strategies for Mn toxicity combine chelation therapy to reduce the body Mn load and iron (Fe) supplementation to reduce Mn binding to proteins that interact with both Mn and Fe. This chapter summarizes our current understanding of Mn homeostasis and the mechanisms of Mn toxicity and highlights the clinical disorders associated with Mn neurotoxicity.

Pathogenesis and treatment of parenteral nutrition-associated liver disease

BACKGROUND

Parenteral nutrition-associated liver disease (PNALD) has been common in patients who require long-term parenteral nutrition. PNALD develops in 40%-60% of infants on long-term parenteral nutrition compared with 15%-40% of adults on home parenteral nutrition for intestinal failure. The pathogenesis of PNALD is multifactorial and remains unclear. There is no specific treatment. Management strategies for its prevention and treatment depend on an understanding of many risk factors. This review aims to provide an update on the pathogenesis and treatment of this disease.

DATA SOURCES

A literature search was performed on the MEDLINE and Web of Science databases for articles published up to October 2011, using the keywords: parenteral nutrition associated liver disease, intestinal failure associated liver disease, lipid emulsions and fish oil. The available data reported in the relevant literatures were analyzed.

RESULTS

The literature search provided a huge amount of evidence about the pathogenesis and management strategies on PNALD. Currently, lack of enteral feeding, extended duration of parenteral nutrition, recurrent sepsis, and nutrient deficiency or excess may play important roles in the pathogenesis of PNALD. Recent studies found that phytosterols, present as contaminants in soy-based lipid emulsions, are also an important factor in the pathogenesis. Moreover, the treatment of PNALD is discussed.

CONCLUSIONS

The use of lipid emulsions, phytosterols in particular, is associated with PNALD. Management strategies for the prevention and treatment of PNALD include consideration of early enteral feeding, the use of specialized lipid emulsions such as fish oil emulsions, and isolated small bowel or combined liver and small bowel transplantation. A greater understanding of the pathogenesis of PNALD has led to promising interventions to prevent and treat this condition. Future work should aim to better understand the mechanisms of PNALD and the long-term outcomes of its treatment.

Parenteral trace elements in children: clinical aspects and dosage recommendations

PURPOSE OF REVIEW

Since the 1970s, it has been known that the supplementation of trace elements with parenteral nutrition is required in order to avoid the clinical manifestations of their deficiencies. However, the correct level of requirements of these trace elements, particularly in paediatrics, has provided some debate. The recent developments might help revise some of the current recommendations, particularly in short-term parenteral nutrition provision.

RECENT FINDINGS

Parenterally fed preterm neonates require routine addition of zinc. Provision of chromium and manganese in parenteral nutrition should be limited, particularly for short-term patients. Newer parenteral iron preparations provide the opportunity for a safer and larger dose of administration.

SUMMARY

Clinicians should prescribe according to the individual requirements and revise the routine practice of providing 'all in one' parenteral trace elements preparations, as these products do not reflect or allow tailored provision in paediatrics and may increase the risk of toxicity.

Enteral and Parenteral Applications of Ketogenic Diet Therapy

Ketogenic diet therapy is a high-fat, low-carbohydrate, moderate-protein regimen that results in a sustained metabolic state of ketosis. The diet was originally designed in the 1920s for treatment of epilepsy, but its use has expanded in recent years to other disorders. Most individuals who undergo this therapy are able to consume the diet orally, but those with restricted oral intake require alternative methods of nutrition. Many of our patients have feeding tubes in place for receiving part or all of their nutrition. It is possible to administer the diet during an acute condition or illness in patients who have previously received their nutrition orally. This may be accomplished enterally via a feeding tube or intravenously as parenteral nutrition. This article addresses enteral and parenteral applications of ketogenic diet therapy and provides examples of the modifications that have been successfully implemented at 4 medical centers.

High prevalence of multiple micronutrient deficiencies in children with intestinal failure: a longitudinal study

OBJECTIVE

To determine the prevalence of micronutrient deficiencies in children with intestinal failure as they transitioned from parenteral nutrition (PN) to enteral nutrition (EN).

STUDY DESIGN

We reviewed medical records of all patients with severe intestinal failure treated from 1999 to 2008 at a multidisciplinary intestinal rehabilitation program who had undergone micronutrient biochemical monitoring.

RESULTS

The cohort of 30 children (mean age, 5 years; range, 2 to 9 years; 18 boys) had median PN duration of 23 weeks (IQR, 13 to 34 weeks). Median transition from PN to full EN lasted 12 weeks (IQR, 8 to 20 weeks); during this transition, 33% of patients had at least one vitamin deficiency and 77% at least one mineral deficiency. After transition to 100% EN, 70% had at least one vitamin deficiency and 77% had at least one mineral deficiency, with the most common deficiencies being vitamin D (68%), zinc (67%), and iron deficiency (37%). After transition to 100% EN, multivariate analysis identified regular use of a multivitamin supplement (P=.004) and intact ileocecal valve (P=.02) as protective against the development of vitamin deficiencies, independent of bowel length, gestational age, and days on PN.

CONCLUSIONS

Children with intestinal failure exhibit a high prevalence of micronutrient deficiencies during intestinal rehabilitation. Regular monitoring and aggressive supplementation in children with intestinal failure is warranted.