Changing the paradigm: omegaven for the treatment of liver failure in pediatric short bowel syndrome

Enteral High Fat-Polyunsaturated Fatty Acid Blend Alters the Pathogen Composition of the Intestinal Microbiome in Premature Infants with an Enterostomy

OBJECTIVE

To determine the effect of enteral fish oil and safflower oil supplementation on the intestinal microbiome in infants with an enterostomy born premature.

STUDY DESIGN

Infants with an enterostomy born premature were randomized to receive early enteral supplementation with a high-fat polyunsaturated fatty acid (HF-PUFA) blend of fish oil and safflower oil vs standard nutritional therapy. We used 16S rRNA gene sequencing for longitudinal profiling of the microbiome from the time of study entry until bowel reanastomosis. We used weighted gene coexpression network analysis to identify microbial community modules that differed between study groups over time. We performed imputed metagenomic analysis to determine metabolic pathways associated with the microbial genes.

RESULTS

Sixteen infants were randomized to receive enteral HF-PUFA supplementation, and 16 infants received standard care. The intestinal microbiota of infants in the treatment group differed from those in the control group, with greater bacterial diversity and lower abundance of Streptococcus, Clostridium, and many pathogenic genera within the Enterobacteriaceae family. We identified 4 microbial community modules with significant differences between groups over time. Imputed metagenomic analysis of the microbial genes revealed metabolic pathways that differed between groups, including metabolism of amino acids, carbohydrates, fatty acids, and secondary bile acid synthesis.

CONCLUSION

Enteral HF-PUFA supplementation was associated with decreased abundance of pathogenic bacteria, greater bacterial diversity, and shifts in the potential metabolic functions of intestinal microbiota.

TRIAL REGISTRATION

ClinicalTrials.gov:NCT01306838.

Intestinal Failure in Children

Children with intestinal failure have had improved survival, particularly those with extreme short bowel syndrome, over the last 10-15 y. This has been attributed to better understanding of the pathophysiology of intestinal failure, improvement in line care, recognition of the importance of a team approach as well as the progress of intestinal transplant as a viable option. Parenteral nutrition remains the cornerstone for the continual survival of these patients. This review will cover contemporary approaches to intestinal failure including post surgical approaches, non-transplant surgery, dietetic and medication approaches during the adaptation process, considerations for home parenteral nutrition and latest in intestinal transplantation.

Intravenous Fat Emulsion Formulations for the Adult and Pediatric Patient: Understanding the Differences

Intravenous fat emulsions (IVFEs) provide essential fatty acids (EFAs) and are a dense source of energy in parenteral nutrition (PN). Parenterally administered lipid was introduced in the 17th century but plagued with side effects. The formulation of IVFEs later on made it a relatively safe component for administration to patients. Many ingredients are common to all IVFEs, yet the oil source(s) and its (their) percentage(s) makes them different from each other. The oil used dictates how IVFEs are metabolized and cleared from the body. The fatty acids (FAs) present in each type of oil provide unique beneficial and detrimental properties. This review provides an overview of IVFEs and discusses factors that would help clinicians choose the optimal product for their patients.

Intestinal transplantation in children: current status

Intestinal transplantation (IT) is the least common form of organ transplantation; however, it has shown exceptional growth and improvement in graft survival rates over the past two decades mainly due to better outcomes achieved during the first year of transplantation (76 % at 1 year), due to improvement in surgical techniques and the development of better immunosupressive therapies as we understand more about the relationship between the recipient and host immune system. There are still ongoing issues with chronic rejection and long-term survival. Intestinal transplantation is still an acceptable therapy for patients with intestinal failure (IF), but it is generally reserved for patients who develop severe and life-threatening complications despite standard therapies, or those who are not able to maintain a good quality of life. The purpose of this review is to describe the current status, indications, outcomes and advances in the field of intestinal transplantation.

Molecular impact of omega 3 fatty acids on lipopolysaccharide-mediated liver damage

BACKGROUND

Growing evidence suggests that omega 3 fatty acid containing lipid emulsions have a beneficial effect on parenteral nutrition associated liver disease (PNALD). However, the cellular and molecular mechanisms responsible for this effect are unclear. In this study, we investigated whether Omegaven™ fish oil emulsion could inhibit lipopolysaccharidase (LPS) mediated liver damage.

METHODS

We examined the effects of Omegaven™ and LPS alone and synergistically on hepatic paraoxonase 1 (PON1), a potent antioxidant protein, ERK1/2 activity, and TLR4 regulation.

RESULTS

LPS did not alter PON1 release from HepG2 cells but did significantly decrease PON1 protein synthesis (44%, P<0.05). Omegaven™ alone had no direct effect on PON1 release. However, it did significantly reverse LPS-mediated decrease in PON1 protein levels (control: 100%; LPS alone: 56+/4%; LPS+Omegaven™: 87+/6%, P<0.05). Furthermore, molecular analysis indicated that Omegaven™ blocked LPS-mediated increase in ERK1/2 activity (35% increase), an important LPS signal transduction pathway. TLR4, the receptor for LPS, was down-regulated in the presence of Omegaven™.

CONCLUSION

Omegaven™ may be beneficial in patients with PNAC because of its ability to reverse LPS-mediated inhibition of antioxidant promoting PON1 expression, and this activity may be in part mediated by the ERK1/2 pathway.

ESPGHAN Committee on Nutrition Position Paper. Intravenous Lipid Emulsions and Risk of Hepatotoxicity in Infants and Children: a Systematic Review and Meta-analysis

The aim of the present article was to perform a systematic review with meta-analysis of available scientific evidence regarding the role of different intravenous lipid emulsions (ILE) in the pathogenesis of cholestasis and parenteral nutrition-associated liver disease. A systematic review of the literature (up to March 2015) identified 23 randomized controlled trials (RCTs). Of these, 17 were performed in preterm infants or critically ill neonates with a short duration of intervention, 2 in older children with short-term use (following surgery or bone marrow transplantation), 1 in neonates with long-term use, and 3 in infants and children receiving long-term parenteral nutrition (PN). Meta-analysis showed no differences in the rate of cholestasis or bilirubin levels associated with short-term use of different ILEs. Because of high heterogeneity of the long-term studies no meta-analysis could be performed. Available studies found that the use of multicomponent fish oil (FO)-containing ILE compared with pure soya bean oil (SO), ILE-reduced liver enzymes, and bilirubin levels in noncholestatic children on long-term PN and one other RCT found that FO-based ILE-reversed cholestasis in a proportion of patients. The ESPGHAN Committee on Nutrition concludes that there is no evidence of a difference in rates of cholestasis or bilirubin levels between different ILE for short-term use in neonates. The use of multicomponent FO-containing ILE may contribute to a decrease in total bilirubin levels in children with IF on prolonged PN. Well-designed RCTs are, however, lacking and long-term effects have not been determined.

The Effect of Fish Oil-Based Lipid Emulsion and Soybean Oil-Based Lipid Emulsion on Cholestasis Associated with Long-Term Parenteral Nutrition in Premature Infants

Purpose. To retrospectively study the effect of fish oil-based lipid emulsion and soybean oil-based lipid emulsion on cholestasis associated with long-term parenteral nutrition in premature infants. Methods. Soybean oil-based lipid emulsion and fish oil-based lipid emulsion had been applied in our neonatology department clinically between 2010 and 2014. There were 61 qualified premature infants included in this study and divided into two groups. Soybean oil group was made up of 32 premature infants, while fish oil group was made up of 29 premature infants. Analysis was made on the gender, feeding intolerance, infection history, birth weight, gestational age, duration of parenteral nutrition, total dosage of amino acid, age at which feeding began, usage of lipid emulsions, and incidence of cholestasis between the two groups. Results. There were no statistical differences in terms of gender, feeding intolerance, infection history, birth weight, gestational age, duration of parenteral nutrition, total dosage of amino acid, and age at which feeding began. Besides, total incidence of cholestasis was 21.3%, and the days of life of occurrence of cholestasis were 53 ± 5.0 days. Incidence of cholestasis had no statistical difference in the two groups. Conclusion. This study did not find the different role of fish oil-based lipid emulsions and soybean oil-based lipid emulsions in cholestasis associated with long-term parenteral nutrition in premature infants.

Omega-3 Fatty Acids in Modern Parenteral Nutrition: A Review of the Current Evidence

Intravenous lipid emulsions are an essential component of parenteral nutrition regimens. Originally employed as an efficient non-glucose energy source to reduce the adverse effects of high glucose intake and provide essential fatty acids, lipid emulsions have assumed a larger therapeutic role due to research demonstrating the effects of omega-3 and omega-6 polyunsaturated fatty acids (PUFA) on key metabolic functions, including inflammatory and immune response, coagulation, and cell signaling. Indeed, emerging evidence suggests that the effects of omega-3 PUFA on inflammation and immune response result in meaningful therapeutic benefits in surgical, cancer, and critically ill patients as well as patients requiring long-term parenteral nutrition. The present review provides an overview of the mechanisms of action through which omega-3 and omega-6 PUFA modulate the immune-inflammatory response and summarizes the current body of evidence regarding the clinical and pharmacoeconomic benefits of intravenous n-3 fatty acid-containing lipid emulsions in patients requiring parenteral nutrition.

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.

Preventing the Progression of Intestinal Failure-Associated Liver Disease in Infants Using a Composite Lipid Emulsion: A Pilot Randomized Controlled Trial of SMOFlipid

BACKGROUND

To examine whether SMOFlipid prevents progression of intestinal failure-associated liver disease (IFALD) in parenteral nutrition (PN)-dependent infants with early IFALD (conjugated bilirubin 17-50 µmol/L, 1-3 mg/dL).

STUDY DESIGN

Pilot multicenter blinded randomized controlled trial comparing SMOFlipid with Intralipid. Patients received the trial lipid for up to 12 weeks, unless they achieved full enteral tolerance sooner. The primary clinical outcome was the serum conjugated bilirubin.

RESULTS

Twenty-four infants (mean age, 6 weeks) participated in the trial (13 Intralipid and 11 SMOFlipid). At the time of trial enrollment, patients in both groups were receiving 90% of their calories by PN. Mean duration on trial was 8 weeks and did not differ according to treatment ( P = .99). At trial conclusion, patients who received SMOFlipid had a lower conjugated bilirubin than those who received Intralipid (mean difference, -59 µmol/L; P = .03). Patients receiving SMOFlipid were also more likely to have a decrease in serum conjugated bilirubin to 0 µmol/L than those in the Intralipid group over the entire observation period (hazard ratio, 10.6; 95%; P = .03). The time to achievement of full enteral tolerance did not differ statistically (hazard ratio, 1.3; P = .59) between the groups. There was no significant difference in safety outcomes between the groups.

CONCLUSIONS

Compared with Intralipid, SMOFlipid reduces the risk of progressive IFALD in children with intestinal failure. This trial was registered at clinicaltrials.gov as NCT00793195.

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.

Omega-3 Fatty Acid-Rich Parenteral Nutrition: Is It a Double-Edged Sword?

Parenteral nutrition (PN) has been strongly associated with intestinal failure-associated liver disease. Cholestasis, liver steatosis, and liver fibrosis are features of this liver injury, which can progress to end stage liver disease. Omega-3 fatty acid rich PN has been shown to alleviate cholestasis and steatosis. There have been reports although suggesting that it may not be able to arrest or reverse the progression to liver fibrosis. In this article, we develop a hypothesis of the mechanism of how Ω-3 fatty acid rich PN may influence the progression of fibrosis.

Prevalence of Gallstones Compared in Children With Different Intravenous Lipids

OBJECTIVE

The aetiology of biliary liver disease in children with intestinal failure treated with long-term parenteral nutrition (PN) is multifactorial. Risks include the lipid component of PN. The aim of the study was to compare prevalence and outcome of gallstones with different types of intravenous lipids.

METHODS

Liver and biliary tract imaging and relevant clinical details were reviewed in 71 patients (37, 52% boys) treated with PN for >3 months. Types of lipid infused were compared with regard to hepatobiliary abnormalities.

RESULTS

In total 369 abdominal ultrasounds were performed in 71 patients of age between 3 months and 17 years. Underlying diagnoses were short bowel syndrome in 20 (28%), small intestinal enteropathy in 34 (48%), and motility disorder in 17 (24%). A total of 67 (94%) children had 362/369 scans on lipid-containing PN. Of the total, 15 (21%) patients had gallstones, 8 (11%) had sludge, and both were detected in 7 (10%) children. The gallstones/sludge resolved in 7 patients (10%) and persisted in 10 (13%). In 6 patients, sludge progressed to form discrete gallstones, and in 9 children, gallstones led to biliary duct dilatation. Four (6%) patients underwent cholecystectomy. Fewer children had abnormalities with the newer mixed lipid emulsion (P = 0.005). There was a higher prevalence of sludge (P = 0.01) on pure soya lipid. Predictors for sludge were young age at PN (P = 0.001), lack of enteral feed (P < 0.001), and motility disorder with stoma (P = 0.002).

CONCLUSIONS

Hepatobiliary pathology is common in children on PN. The use of mixed lipid was associated with less biliary complications and should be the first choice of treatment in children.

Parenteral Soy Oil and Fish Oil Emulsions: Impact of Dose Restriction on Bile Flow and Brain Size of Parenteral Nutrition-Fed Neonatal Piglets

BACKGROUND

Parenteral nutrition (PN)-associated liver disease (PNALD) remains a significant cause of morbidity and mortality for neonates dependent on PN. Total fat emulsion dose and composition, particularly the large amount of ω-6 long-chain polyunsaturated fatty acids in plant oils, have been proposed as risk factors for PNALD. We hypothesized restriction of the dose of emulsion would prevent PNALD, regardless of the composition, but growth could be compromised.

METHODS

Using a neonatal piglet model, we compared conventional soy oil emulsion (Intralipid), dosed high (SO10, n = 8: 10 g/kg/d) and low (SO5, n = 6: 5 g/kg/d), with fish oil (Omegaven), dosed low (FO5, n = 8: 5 g/kg/d). Piglets were given isonitrogenous PN for 14 days. The normal range for all parameters was determined by measurement in equivalent aged sow-reared piglets.

RESULTS

Bile flow was lower with high-dose Intralipid, outside the normal range, while higher for the other groups (SO10, 5.4 µg/g; SO5, 8.6 µg/g; FO5, 13.4 µg/g; P = .010; normal range, 6.5-12.2 µg/g). Total body weight was low in all treatment groups (SO10, 4.4 kg; SO5, 4.5 kg; FO5, 5.0 kg; P = .038; normal range, 5.2-7.3 kg). Brain weight was not different between groups (SO10, 40.3 g; SO5, 36.0 g; FO5, 36.6 g; P = .122; normal range, 41.8-51.4 g). Corrected for body weight, brain weight was lowest in the fish oil group (SO10, 9.3 g/kg; SO5, 8.0 g/kg; FO5, 7.3 g/kg; P < .001; normal range, 5.9-9.0 g/kg).

CONCLUSION

Low-dose fat emulsions reduce the risk of developing PNALD. Further investigation of the risk to brain development in neonates exposed to dose restriction, particularly with fish oil, is required.

Glucagon-Like Peptide-2 Alters Bile Acid Metabolism in Parenteral Nutrition--Associated Liver Disease

BACKGROUND

We aim to study the mechanisms underlying our previous finding that exogenous glucagon-like peptide-2 (GLP-2) treatment in a preclinical model of neonatal parenteral nutrition-associated liver disease (PNALD) improves cholestasis.

METHODS

Neonatal piglets received 17 days of parenteral nutrition (PN) therapy and either saline control (PN/Saline n = 8) or GLP-2 treatment at 11 nmol/kg/d (PN/GLP-2, n = 7). At terminal laparotomy, bile and liver samples were collected. The relative gene expression of enzymes involved in bile acid synthesis, regulation, and transport was measured in liver by reverse-transcriptase quantitative polymerase chain reaction. Bile acid composition in bile was determined using tandem mass spectrometry. Data were analyzed using 1-way analysis of variance (ANOVA) or Kruskal-Wallis ANOVA.

RESULTS

GLP-2 increased the expression of bile acid export genes: multidrug resistance-associated proteins 2 (MRP2) (P = .002) and 3 (MRP3) (P = .037) over saline control. GLP-2 increased expression of Farnesoid X receptor (FXR) (P < .001) and CYP7A1 (cytochrome P450, family 7, subfamily A, polypeptide 1) (P = .03). GLP-2 treatment was associated with decreased concentrations of taurohyocholic acid and conjugates of toxic lithocholic acid (P < .01). GLP-2 treatment increased the liver bile acid content.

CONCLUSIONS

GLP-2 treatment was associated with alterations in the hepatic expression of genes involved in bile acid metabolism. The transcriptomic results indicate the mechanisms at the transcriptional level acting to regulate bile acid synthesis and increase bile acid export. Differences in bile acid profiles further support a beneficial role for GLP-2 therapy in PNALD.

Impact of Intestinal Rehabilitation Program and Its Innovative Therapies on the Outcome of Intestinal Transplant Candidates

OBJECTIVES

The outcome of children with intestinal failure has improved during the past decade following the introduction of novel therapies by dedicated intestinal rehabilitation programs (IRP). The aim of the present study was to assess the impact of IRP on the outcome of intestinal transplant (IT) candidates and the transplant waiting list.

METHODS

A retrospective cohort study of children assessed for IT (n = 84) during a 10-year period. Comparisons were made among the following 3 time periods: before the establishment of our center's IRP (1999-2002; n = 33), early IRP (2003-2005; n = 18), and late IRP (2006-2009; n = 33). The following endpoints were used: patient outcome following IT assessment (not listed, listed and removed from the list, received transplant, died while on the list), patient characteristics at IT assessment, and patient status at the end of the study.

RESULTS

The late-IRP era was associated with an increase in patients who were not listed (42% vs 28% at other periods, P = NS) and patients who were removed from the IT waiting list because of clinical improvement (P < 0.0005), and a decrease in those who died before transplant (15% vs >60% at other periods, P < 0.0005). The cause of death shifted from traditional causes such as liver failure or sepsis to other comorbid conditions (P < 0.005). Improved liver function at listing was also observed during late IRP (P < 0.005).

CONCLUSIONS

Treatment by IRP, coupled with recent advances in the medical management of intestinal failure, is associated with improved survival and outcome of patients waiting for IT, and may lead to overall reduction in the number of IT in the future.

Pediatric intestinal transplant listing criteria - a call for a change in the new era of intestinal failure outcomes

Current listing indications used for intestinal transplantation (IT) were proposed in 2001. We undertook the present single center study to see if these criteria are still valid. The 2001 criteria (advanced cholestasis, loss of >50% central venous catheter (CVC) sites, ≥2 sepsis/year, ultrashort bowel) were compared in children with intestinal failure in old era-1998-2005 (N = 99) to current era-2006-2012 (N = 91) to predict the need for IT using sensitivity, specificity, NPV and PPV. Two 2001 criteria had poorer predictive value in the current era: Advanced cholestasis (PPV 64% old vs. 40% current era; sensitivity 84% vs. 65%, respectively) and ultrashort bowel (PPV 100% old vs. 9% current era; sensitivity 10% vs. 4%, respectively). Three newly proposed criteria had high predictive value: ≥2 ICU admissions (p = 0.0001, OR 23.6, 95% CI 2.7-209.8), persistent bilirubin >75 mmol/L despite lipid strategies (p = 0.0005, OR 24.0, 95% CI 3.2-177.4), and loss of ≥3 CVC sites (p = 0.0003, OR 33.3, 95% CI 18.8-54.0). There was 98% probability of needing IT when two of these new criteria were present. The 2001 IT criteria have limited predictive ability in the current era and should be revised. A multicenter study is required to validate the findings of this single center experience.

Review on hepatic explant pathology of pediatric intestinal transplant recipients: Is it time for an oil change?

A recent study attempts to add to the body of evidence that is emerging regarding the fish oil parenteral lipid product Omegaven™. The authors have shown from explant livers of children on chronic parenteral nutrition with Omegaven™ that biochemical improvement in cholestasis does not always reflect improvement in liver histology. These findings support 2 small case series that were previously published. Despite improvement and resolution of hyperbilirubinemia in all six infants, five of six infants had persistent or progressive hepatic fibrosis, while only one infant had regression of fibrosis. The study raises questions of whether there is a window of opportunity for efficacy of this preparation; also, an important question is if this omega-3 fatty acid-rich preparation is superior to newer "blended lipids" containing olive, coconut, soy, and fish oil.

Intestinal failure-associated liver disease: a position paper of the ESPGHAN Working Group of Intestinal Failure and Intestinal Transplantation

Intestinal failure-associated liver disease is the most prevalent complication affecting children with intestinal failure receiving long-term parenteral nutrition. This paper reviews the definition, diagnostic criteria, pathogenesis, and risk factors. The authors discuss the role of enteral nutrition, parenteral nutrition, and its components, especially lipid emulsions. The authors also discuss the surgical treatment, including intestinal transplantation, its indications, technique, and results, and emphasise the importance of specialised intestinal failure centres.

Platelet Arachidonic Acid Deficiency May Contribute to Abnormal Platelet Function During Parenteral Fish Oil Monotherapy in a Piglet Model

BACKGROUND

Fish oil monotherapy has been an advance for treating intestinal failure-associated liver disease (IFALD). However, such patients are at risk of bleeding complications from liver disease and because fish oil can inhibit thrombosis. We have previously reported abnormal platelet function in neonatal piglets given fish oil monotherapy during parenteral nutrition (PN). The purpose of this study was to determine if abnormal fatty acid composition of the platelets could explain the prior observed antiplatelet effect.

METHODS

Neonatal piglets were assigned to 2 treatments: PN with fish oil monotherapy (FO; n = 4) or PN with soy oil (SO; n = 5). On day 14, plasma was collected and platelets isolated by centrifuging. The fatty acid content in plasma and platelet plug were measured using gas liquid chromatography and compared with controls (CON; n = 5).

RESULTS

The arachidonic acid (AA) content in the FO group was on average half that of the SO group, in both the platelets (FO, 3.5% vs SO, 7.6%; P = .021; CON, 4.5%-11%) and the plasma (FO, 3.8% vs SO, 9.2%; P = .002; CON, 6.1%-9.5%). No bleeding complications were observed for any piglets during PN treatment.

CONCLUSIONS

Using platelet mapping, we have previously shown that neonatal piglets given fish oil monotherapy have abnormal platelet function in the AA pathway. This report demonstrates that such an abnormality can be explained by platelet AA deficiency. Platelet mapping and platelet fatty acid analysis should be undertaken in human infants treated with fish oil monotherapy during PN.

Low-fat, high-carbohydrate parenteral nutrition (PN) may potentially reverse liver disease in long-term PN-dependent infants

INTRODUCTION

Parenteral nutrition-associated cholestasis (PNAC) is a complication of long-term parenteral nutrition (PN). Removal of lipids may reverse PNAC but compromises the energy to ensure infant growth. The purpose of this study was to test whether a low-fat, high-carbohydrate PN regimen, which prevents and reverses PNAC in adults, could do the same in infants. This regimen could potentially avoid the problem of diminished energy input after removing nutritional lipids.

METHODS

Infants developing PNAC over a 2-year period were started on a low-fat PN regimen with calories primarily from carbohydrates. The fat-free PN, containing 314 kJ/ml, was provided 5-6 times a week and fat, including essential fatty acids and fat-soluble vitamins, 1-2 times a week. Enteral feeding was continued according to individual tolerance.

RESULTS

The study included 10 infants with short bowel syndrome (six with intestinal failure due to necrotizing enterocolitis, one with gastroschisis, one with complications due to unrecognized anal atresia and two with midgut volvulus). Median duration of PN with fat before initiating the low-fat regime was 69 days (25-75 % percentile: 41-75 days), and mean s-bilirubin was 139 µmol/l (range 87-323 µmol/l). Median duration with low-fat regimen was 69 days (25-75 % percentile: 18-123 days). Bilirubin reversed to normal (<50 µmol/l) in all infants. Seven children showed catch-up growth. No essential fatty acid deficiency, steatosis or deaths were observed.

CONCLUSIONS

A low-fat, high-carbohydrate PN regimen together with enteral feeding is well tolerated and may be used in reversing liver disease in PN-dependent infants without compromising growth.

Intestinal transplant registry report: global activity and trends

The Registry has gathered information on intestine transplantation (IT) since 1985. During this time, individual centers have reported progress but small case volumes potentially limit the generalizability of this information. The present study was undertaken to examine recent global IT activity. Activity was assessed with descriptive statistics, Kaplan-Meier survival curves and a multiple variable analysis. Eighty-two programs reported 2887 transplants in 2699 patients. Regional practices and outcomes are now similar worldwide. Current actuarial patient survival rates are 76%, 56% and 43% at 1, 5 and 10 years, respectively. Rates of graft loss beyond 1 year have not improved. Grafts that included a colon segment had better function. Waiting at home for IT, the use of induction immune-suppression therapy, inclusion of a liver component and maintenance therapy with rapamycin were associated with better graft survival. Outcomes of IT have modestly improved over the past decade. Case volumes have recently declined. Identifying the root reasons for late graft loss is difficult due to the low case volumes at most centers. The high participation rate in the Registry provides unique opportunities to study these issues.

Animal models of gastrointestinal and liver diseases. Animal models of infant short bowel syndrome: translational relevance and challenges

Intestinal failure (IF), due to short bowel syndrome (SBS), results from surgical resection of a major portion of the intestine, leading to reduced nutrient absorption and need for parenteral nutrition (PN). The incidence is highest in infants and relates to preterm birth, necrotizing enterocolitis, atresia, gastroschisis, volvulus, and aganglionosis. Patient outcomes have improved, but there is a need to develop new therapies for SBS and to understand intestinal adaptation after different diseases, resection types, and nutritional and pharmacological interventions. Animal studies are needed to carefully evaluate the cellular mechanisms, safety, and translational relevance of new procedures. Distal intestinal resection, without a functioning colon, results in the most severe complications and adaptation may depend on the age at resection (preterm, term, young, adult). Clinically relevant therapies have recently been suggested from studies in preterm and term PN-dependent SBS piglets, with or without a functional colon. Studies in rats and mice have specifically addressed the fundamental physiological processes underlying adaptation at the cellular level, such as regulation of mucosal proliferation, apoptosis, transport, and digestive enzyme expression, and easily allow exogenous or genetic manipulation of growth factors and their receptors (e.g., glucagon-like peptide 2, growth hormone, insulin-like growth factor 1, epidermal growth factor, keratinocyte growth factor). The greater size of rats, and especially young pigs, is an advantage for testing surgical procedures and nutritional interventions (e.g., PN, milk diets, long-/short-chain lipids, pre- and probiotics). Conversely, newborn pigs (preterm or term) and weanling rats provide better insights into the developmental aspects of treatment for SBS in infants owing to their immature intestines. The review shows that a balance among practical, economical, experimental, and ethical constraints will determine the choice of SBS model for each clinical or basic research question.

Preliminary findings of long-term neurodevelopmental outcomes of infants treated with intravenous fat emulsion reduction for the management of parenteral nutrition-associated cholestasis

INTRODUCTION

Parenteral nutrition-associated cholestasis (PNAC) is linked with the administration of soybean-based intravenous fat emulsion (IVFE). IVFE reduction (IFER) may be an effective management strategy for PNAC; however, long-term associated neurodevelopmental outcomes (NDOs) for infants undergoing IFER have not been measured previously. This single-institution, prospective study examined the risk for negative NDOs and key predictors of NDOs associated with IFER.

METHODS

Patients (2-5 years) treated with soybean-based IFER as neonates underwent NDO measurements, including Ages and Stages Questionnaires-3 (ASQ-3), Parents' Evaluations of Developmental Status (PEDS), and Behavior Assessment System for Children, Second Edition Preschool, Parent (BASC-2 PRS-P). The relationship between NDOs and predictive variables was evaluated.

RESULTS

A total of 25 children had a complete PEDS survey, and 17 were found to be "not at risk." The BASC-2 PRS-P evaluation (n = 18 patients) showed that all 4 composite domains fell within the normative developmental range, and 67%-89% of patients were observed to be "typically developing." For the primary outcome measure, ASQ-3, 82.4%-94.4% of patients were "not at risk." Logistical regression analyses were performed to examine risk factors contributing to negative NDOs. Of children completing all NDO studies, IFER-related variables (eg, development of essential fatty acid deficiency, duration of IFER, and mean IVFE dose) were not found to be predictors of adverse NDOs.

CONCLUSIONS

This study represents the first report of NDOs in pediatric patients treated with IFER. IFER-treated patients score within the normative range most of the time. IFER-related variables were not found to be associated with negative NDOs. The results set the stage for a larger, multicenter, prospective study.

Short bowel syndrome in children: surgical and medical perspectives

The main cause of intestinal failure in children is due to short bowel syndrome (SBS) resulting from congenital or acquired intestinal lesions. From the first lengthening procedure introduced by Bianchi, the last three decades have seen lengthening procedures established as fundamental components of multidisciplinary intestinal rehabilitation programs. Debate on indications and timing of the procedures is still open leaving SBS surgical treatment a great challenge. However, enteral autonomy is possible only with an individualized approach remembering that each SBS patient is unique. Current literature on autologous gastrointestinal reconstruction technique was reviewed aiming to assess a comprehensive pathway in SBS non-transplant management.

Scientific, economic, regulatory, and ethical challenges of bringing science-based pediatric nutrition products to the U.S. market and ensuring their availability for patients

Many nutrition products and related drugs are unavailable or not consistently available to clinicians despite a body of clinical data and experience supporting their use. Many of these can be related to drug shortages that have increased since 2009. In addition, there are potentially useful products that are not approved for a specific use or are no longer being manufactured. This review broadly examines the product availability gap from the perspectives of a clinician/former nutrition industry medical director and an economist. The process of pediatric nutrition product and related drug innovation, as well as its drivers and the steps involved in bringing a product to market, is first described. This is followed by an assessment of factors influencing product availability beyond the innovation process, including regulatory issues, manufacturing compliance, purchasing practices, and other factors related to drug and nutrition product pricing and reimbursement. Three pediatric case examples are reviewed and placed in the context of the prior review. Last, recent and future possible steps toward closing the product availability gap are discussed.

Impact of Providing a Combination Lipid Emulsion Compared With a Standard Soybean Oil Lipid Emulsion in Children Receiving Parenteral Nutrition: A Systematic Review and Meta-Analysis

BACKGROUND

Soybean oil lipid emulsion may compromise immune function and promote hepatic damage due to its composition of long-chain fatty acids, phytosterols, high proportion of ω-6 fatty acids, and low α-tocopherol levels. Combination lipid emulsions have been developed using medium-chain triglyceride oil, fish oil, and/or olive oil, which provide adequate essential fatty acids, a smaller concentration of ω-6 fatty acids, and lower levels of phytosterols. The purpose of this systematic review is to determine if combination lipid emulsions have a more favorable impact on bilirubin levels, triglyceride levels, and incidence of infection compared with soybean oil lipid emulsions in children receiving parenteral nutrition.

METHODS

This study comprises a systematic review of published studies. Data were sufficient and homogeneous to conduct a meta-analysis for total bilirubin and infection.

RESULTS

Nine studies met the inclusion criteria. Meta-analysis showed that combination lipid emulsion decreased total bilirubin by a mean difference of 2.09 mg/dL (95% confidence interval, -4.42 to 0.24) compared with soybean oil lipid emulsion, although the result was not statistically significant (P = .08). Meta-analysis revealed no statistically significant difference in incidence of infection between the combination lipid emulsion and the soybean oil lipid emulsion groups (P = .846). None of the 4 studies that included triglyceride as an outcome detected a significant difference in triglyceride levels between the combination lipid emulsion and soybean oil lipid emulsion groups.

CONCLUSION

There is inadequate evidence that combination lipid emulsions offer any benefit regarding bilirubin levels, triglyceride levels, or incidence of infection compared with soybean oil lipid emulsions.

Phytosterols promote liver injury and Kupffer cell activation in parenteral nutrition-associated liver disease

Parenteral nutrition-associated liver disease (PNALD) is a serious complication of PN in infants who do not tolerate enteral feedings, especially those with acquired or congenital intestinal diseases. Yet, the mechanisms underlying PNALD are poorly understood. It has been suggested that a component of soy oil (SO) lipid emulsions in PN solutions, such as plant sterols (phytosterols), may be responsible for PNALD, and that use of fish oil (FO)-based lipid emulsions may be protective. We used a mouse model of PNALD combining PN infusion with intestinal injury to demonstrate that SO-based PN solution causes liver damage and hepatic macrophage activation and that PN solutions that are FO-based or devoid of all lipids prevent these processes. We have furthermore demonstrated that a factor in the SO lipid emulsions, stigmasterol, promotes cholestasis, liver injury, and liver macrophage activation in this model and that this effect may be mediated through suppression of canalicular bile transporter expression (Abcb11/BSEP, Abcc2/MRP2) via antagonism of the nuclear receptors Fxr and Lxr, and failure of up-regulation of the hepatic sterol exporters (Abcg5/g8/ABCG5/8). This study provides experimental evidence that plant sterols in lipid emulsions are a major factor responsible for PNALD and that the absence or reduction of plant sterols is one of the mechanisms for hepatic protection in infants receiving FO-based PN or lipid minimization PN treatment. Modification of lipid constituents in PN solutions is thus a promising strategy to reduce incidence and severity of PNALD.

Assessment and outcome of children with intestinal failure referred for intestinal transplantation

BACKGROUND & AIMS

Chronic intestinal failure (CIF) requires long term parenteral nutrition (PN) and, in some patients, intestinal transplantation (ITx). Indications and timing for ITx remain poorly defined. In the present study we aimed to analyze causes and outcome of children with CIF.

METHODS

118 consecutive patients referred to our institution were assessed by a multidisciplinary team and four different categories were defined retrospectively based on their clinical course: Group 1: patients with reversible intestinal failure; group 2: patients unsuitable for ITx, group 3: patients listed for ITx; group 4: patients stable under PN. Analysis involved comparison between groups for nutritional status, central venous catheter (CVC) related complications, liver disease, and outcome after transplantation by using non parametric tests, Mann-Whitney tests, Kruskal-Wallis, Wilcoxon signed rank tests and chi square distribution for percentage.

RESULTS

118 children (72 boys) with a median age of 15 months at referral (2 months-16 years) were assessed. Etiology of IF was short bowel syndrome [n = 47], intractable diarrhea of infancy [n = 37], total intestinal aganglionosis [n = 18], and chronic intestinal pseudoobstruction [n = 17]. Most patients (89.8%) were totally PN dependent, with 48 children (40.7%) on home-PN prior to admission. Nutritional status was poor with a median body weight at -1.5 z-score (ranges: -5 to +2.5) and median length at -2.0 z-score (ranges: -5.5 to +2.3). The mean number of CVC inserted per patient was 5.2 (range 1-20) and the mean number of CRS per patient was 5.5 (median: 5; range 0-12) Fifty-five patients (46.6%) had thrombosis of ≥2 main venous axis. At admission 34.7% of patients had elevated bilirubin (≥50 μmol/l), and 19.5% had platelets <100,000/ml, and 15% had both. Liver biopsy performed in 79 children was normal (n = 4), or showed F1 or F2 fibrosis (n = 29), bridging fibrosis F3 (n = 20), or cirrhosis (n = 26). Group 1 included 10 children finally weaned from PN (7-years survival: 100%). Group 2 included 12 children with severe liver disease and associated disorders unsuitable for transplantation (7-years survival: 16.6%). Group 3 included 66 patients (56%) who were listed for small bowel or liver-small bowel transplantation, 62/66 have been transplanted (7 years survival: 74.6%). Factors influencing outcome after liver-ITx were body weight (p < .004), length (p < .001), pre-Tx bilirubin plasma level (p < .001) and thrombosis (p < .01) for isolated ITx, Group 4 included 30 children (25.4%) with irreversible IF considered as potential candidates for isolated ITx. Four children were lost from follow up and 3 died within 2 years (survival 88.5%). Among potential candidates, the following parameters improved significantly during the first 12 months of follow up: Body weight (p.0001), length (p < .0001) and bilirubin (p < .0001).

CONCLUSIONS

many patients had a poor nutritional status with severe complications especially liver disease. PN related complications were the most relevant indication for ITx, but also a negative predictor for outcome. Early patient referral for Tx-assessment might help to identify and separate children with irreversible IF from children with transient IF or uncomplicated long-term PN, allowing to adapt a patient-based treatment strategy including or not ITx.

Fish Oil (SMOFlipid) and olive oil lipid (Clinoleic) in very preterm neonates

OBJECTIVES

Fat emulsions used in Australia for parenteral nutrition in preterm neonates have been based on either soybean oil or olive oil (OO). OO lipid Clinoleic has a high ratio of n-6 to n-3 fatty acids (9:1); this may not be ideal for long-chain polyunsaturated fatty acids supply. Newly available SMOFlipid has an appropriate ratio of n-6 to n-3 fatty acids (2.5:1). SMOFlipid also contains OO (25%), coconut oil (30%), and soybean oil (30%). The aims of the study were to evaluate the safety of the SMOFlipid and to test the hypothesis that SMOFlipid would lead to increased omega-3 long-chain polyunsaturated fatty acid levels and reduced oxidative stress as compared with Clinoleic in preterm neonates (<30 weeks).

METHODS

Preterm neonates (23-30 weeks) were randomised to receive Clinoleic or SMOFlipid emulsion for 7 days. Investigators and outcome assessors were masked to allocation. Plasma F2-isoprostanes (lipid peroxidation marker), red blood cell fatty acids, and vitamin E were measured before and after the study. Blood culture positive sepsis and growth were monitored for safety.

RESULTS

Thirty of 34 participants completed the study. Both emulsions were well tolerated without any adverse events. F2-isoprostane levels were reduced in the SMOFlipid group as compared with baseline. Eicosapentanoic acid and vitamin E levels were significantly increased in the SMOFlipid group. Oleic acid and linoleic acid levels were increased in both groups. No significant differences were noted in poststudy docosahexaenoic acid levels in both groups despite higher levels of docosahexaenoic acid in SMOFlipid.

CONCLUSIONS

SMOFlipid was safe, well tolerated, and showed beneficial effect in terms of reduction of oxidative stress by reducing lipid peroxidation levels in high-risk preterm neonates.

New generation lipid emulsions prevent PNALD in chronic parenterally fed preterm pigs

Total parenteral nutrition (TPN) is associated with the development of parenteral nutrition-associated liver disease (PNALD) in infants. Fish oil-based lipid emulsions can reverse PNALD, yet it is unknown if they can prevent PNALD. We studied preterm pigs administered TPN for 14 days with either 100% soybean oil (IL), 100% fish oil (OV), or a mixture of soybean oil, medium chain triglycerides (MCTs), olive oil, and fish oil (SL); a group was fed formula enterally (ENT). In TPN-fed pigs, serum direct bilirubin, gamma glutamyl transferase (GGT), and plasma bile acids increased after the 14 day treatment but were highest in IL pigs. All TPN pigs had suppressed hepatic expression of farnesoid X receptor (FXR), cholesterol 7-hydroxylase (CYP7A1), and plasma 7α-hydroxy-4-cholesten-3-one (C4) concentrations, yet hepatic CYP7A1 protein abundance was increased only in the IL versus ENT group. Organic solute transporter alpha (OSTα) gene expression was the highest in the IL group and paralleled plasma bile acid levels. In cultured hepatocytes, bile acid-induced bile salt export pump (BSEP) expression was inhibited by phytosterol treatment. We show that TPN-fed pigs given soybean oil developed cholestasis and steatosis that was prevented with both OV and SL emulsions. Due to the presence of phytosterols in the SL emulsion, the differences in cholestasis and liver injury among lipid emulsion groups in vivo were weakly correlated with plasma and hepatic phytosterol content.

Impact of new-generation lipid emulsions on cellular mechanisms of parenteral nutrition-associated liver disease

Parenteral nutrition (PN) is a life-saving nutritional support for a large population of hospitalized infants, and lipids make a substantial contribution to their energy and essential fatty acid (FA) needs. A challenge in the care of these infants is that their metabolic needs require prolonged PN support that increases the risk of PN-associated liver disease (PNALD). In recent years, the emergence of new parenteral lipid emulsions containing different source lipids and FA profiles has created nutritional alternatives to the first-generation, soybean oil-based lipid emulsion Intralipid. The limited U.S. introduction of the new-generation fish-oil emulsion Omegaven has generated promising results in infants with PNALD and spawned a renewed interest in how PN and lipid emulsions, in particular, contribute to this disease. Studies suggest that the lipid load and constituents, such as specific FAs, ratio of n-3 (ω-3) to n-6 (ω-6) long-chain polyunsaturated FAs, phytosterols, and vitamin E content, may be involved. There is an existing literature describing the molecular mechanisms whereby these specific nutrients affect hepatic metabolism and function via lipid and bile acid sensing nuclear receptors, such as peroxisome proliferator-activated receptor α, liver X receptor, and farnesoid X receptor, yet virtually no information as to how they interact and modulate liver function in the context of PN in pediatric patients or animal models. This article will review the recent development of parenteral lipid emulsions and their influence on PNALD and highlight some of the emerging molecular mechanisms that may explain the effects on liver function and disease.

Intestinal transplantation: an unexpected journey. Robert E. Gross Lecture

The development of pediatric intestine transplantation has required continuous refinements in the management of intestinal failure, surgical technique, and perioperative care. The development of better immunosuppressive management (cyclosporine in 1978 and tacrolimus in 1989) and enhancements in our understanding of the relationship between recipient and host immune systems have resulted in better long-term survival. Paralleling this, advancements in the organ procurement techniques and organ preservation solutions have made possible the procurement and transplantation of various types of intestine containing grafts tailored to the needs of the various indications for which intestine transplantation is being performed. With improved outcomes, the indications for intestine transplantation have been better defined in the context of risk benefit for the most important complications of TPN, which include liver disease, life threatening infection, and loss of central venous access. The first survivors of transplantation would also go on to demonstrate the interaction (host-versus-graft and graft-versus-host) between recipient and donor immunocytes (brought with the allograft), which under the cover of immunosuppression allows varying degrees of graft acceptance. The struggle to achieve better transplantation survival outcomes came about with the development of improved strategies to better manage intestinal failure. This has been accomplished largely through the establishment of centers that incorporate a multidisciplinary team approach to medical and surgical care. Intestine transplantation represents a lifesaving therapy for many patients with intestinal failure who have significant complications of their disease. It is hoped that with the minimization of immunosuppression strategies currently used, the long-term survival of these intestine organ transplant recipients will continue improving, together with their rehabilitation and quality-of-life.

A double-blind randomised controlled trial of fish oil-based versus soy-based lipid preparations in the treatment of infants with parenteral nutrition-associated cholestasis

BACKGROUND

Infants receiving prolonged parenteral nutrition (PN) are at risk of PN-associated cholestasis (PNAC). This can progress to hepatic failure and death if PN cannot be discontinued. Fish oil-based parenteral lipid preparation (FOLP) has been shown to be beneficial in case studies.

OBJECTIVES

(1) To evaluate whether FOLP could halt or reverse the progression of PNAC compared with soy-based parenteral lipid preparation (SLP) and (2) to assess the effects of FOLP on liver function and physical growth.

DESIGN

double-blind randomised controlled trial.

SETTING

level III neonatal intensive care unit.

PARTICIPANTS

infants with PNAC (plasma-conjugated bilirubin concentration ≥ 34 µmol/l or 2 mg/dl) expected to be PN-dependent for >2 weeks.

INTERVENTION

to receive either FOLP or SLP at 1.5 g/kg/day.

PRIMARY OUTCOME MEASURE

reversal of PNAC within 4 months after commencement of lipid treatment; secondary outcomes: rate of change of weekly liver function tests, infant growth parameters, blood lipid profile and episodes of late-onset sepsis.

RESULTS

A total of 9 infants were randomised to the FOLP group and 7 to the SLP group. There was no significant difference in reversal of PNAC at 4 months between groups. Rates of increase of plasma-conjugated bilirubin and alanine aminotransferase in the SLP group were significantly greater than the FOLP group (13.5 vs. 0.6 µmol/l per week and 9.1 vs. 1.1 IU/l per week, respectively, p = 0.03). Increased enteral nutrition was associated with significant improvement of PNAC in infants receiving FOLP compared with SLP (-8.5 vs. -1.6 µmol/l per 10% increase in enteral nutrition, respectively). The study was terminated prematurely.

CONCLUSIONS

progression of PNAC in PN-dependent infants can be halted by replacing SLP with FOLP and reversed by increasing the proportion of enteral nutrition in infants receiving FOLP. Replacement of SLP with FOLP in PN-dependent infants who develop PNAC may be considered.

Management of short bowel syndrome

Most intestinal failure in children is due to short bowel syndrome (SBS) where congenital or acquired lesions have led to an extensive loss of intestinal mass. The vast majority of morbidity and mortality of patients with SBS is due to complications secondary to their long term dependence on parenteral nutrition. In response to SBS, the intestine undergoes a process of remodeling termed adaptation. Principles guiding the medical management of SBS include providing adequate parenteral nutrition, fluids and electrolytes for growth and normal development, promoting small bowel adaptation, and preventing and treating complications related to the patient's underlying disease and their parenteral nutrition. Catheter associated blood stream infection (CABSI) is major source of morbidity and mortality in patients with intestinal failure from SBS. Intestinal failure associated liver disease (IFALD)is another major source of morbidity and mortality in patients with SBS. IFALD is the most consistent negative predictor of outcome including death and continued parenteral nutrition dependence. Enteral nutrition is critical for intestinal adaptation and preventing IFALD. Patients with SBS who develop dilated dysmotile segments may benefit from autologous intestinal reconstruction surgery (AIRS) with the goal of decreasing stasis and disordered motility through intestinal narrowing and lengthening. Patients with SBS should be referred for transplantation if they have failed intestinal rehabilitation including AIRS, have no reasonable chance for enteral feeding tolerance, develop irreversible IFALD, have recurrent sepsis, or have exhausted their central venous access sites. With improvements in medical and surgical care, overall survival of patients with SBS now exceeds 90%.

Use of Fish Oil-Based Lipid Emulsions in Infants With Intestinal Failure-Associated Liver Disease: A Case Series

The use of fish oil-based lipid emulsions (FOLE) in the treatment of intestinal failure-associated liver disease (IFALD) remains investigational. Additional evidence for safety and efficacy, particularly in the neonatal and pediatric populations, is needed. Retrospective chart review was conducted on 10 infants with short bowel syndrome who received FOLE for IFALD. Direct bilirubin concentrations normalized in surviving subjects within 4.1 to 22.7 weeks of starting treatment. Although earlier initiation of FOLE was not associated with more rapid normalization of direct bilirubin concentrations, it trended toward a significant correlation with reduced length of hospital stay (P = .058). The reduction in direct bilirubin levels and transition from parenteral to enteral feeding were statistically significant within 6 weeks of initiating the FOLE. Subjects did not have impaired growth and did not develop an essential fatty acid deficiency. These infants were discharged from the hospital 7.9 to 42.3 weeks after starting FOLE treatment, and 2 infants had transitioned completely off parenteral nutrition at discharge. In this study, FOLE appeared to be a safe and effective treatment for IFALD in infants with short bowel syndrome. Future studies are necessary to determine whether FOLE can help to prevent or shorten the duration of cholestasis.

Role of parenteral lipid emulsions in the preterm infant

Parenteral nutrition (PN) is necessary for infants unable to receive adequate calories enterally due to prematurity, decreased bowel length, or functional intestinal disorders. While PN can be life saving, its use is associated with significant risks of sepsis from catheter-associated infections and progressive liver dysfunction from prolonged use. The preterm infant population is at highest risk for these complications due to the presence of multiple comorbidities and immaturity of the biliary system. Strong data has implicated parenteral lipids in the multifactorial pathogenesis of PN-associated liver disease (PNALD). However, lipids are essential in early infant development, particularly in the neurocognitive development of preterm infants. Substitution of the lipid source from soybean oil to fish oil has emerged as a safe and efficacious treatment of PNALD, with marked improvements in morbidity and mortality. Knowledge of the developmental needs and physiologic limitations of preterm infants is crucial to optimizing parenteral lipid administration to nurture growth, and minimize and treat associated complications. The purpose of this review is to provide an overview of lipid requirements of the preterm infant and discuss the role of parenteral lipid emulsions in the management of PNALD and other diseases of prematurity.

Mechanisms for the effects of fish oil lipid emulsions in the management of parenteral nutrition-associated liver disease

Parenteral nutrition (PN) can be life saving for infants unable to adequately absorb enteral nutrients due to intestinal failure from inadequate bowel length or function. However, long-term PN carries significant morbidity and mortality, with 30 to 60% of patients developing progressive liver dysfunction. The etiology of PN-associated liver disease (PNALD) is poorly understood, however the involvement of lipid emulsions in its pathogenesis has been clearly established, with new emphasis emerging on the role of omega-6 polyunsaturated fatty acids and omega-3 polyunsaturated fatty acids. Recent studies evaluating the use of parenteral fish oil lipid emulsions instead of soybean oil lipid emulsions have demonstrated marked improvements in cholestasis, morbidity, and mortality in patients with PNALD treated with fish oil. This review provides an overview of the role of lipid emulsions in the pathogenesis of PNALD and the proposed mechanisms by which parenteral fish oil lipid emulsions may be exerting their beneficial effects.

Lipid emulsions in parenteral nutrition: current applications and future developments

INTRODUCTION

A parenteral lipid emulsion (LE), used as a key source of energy, essential fatty acids (FAs), and fat-soluble vitamins, is an integral part of a parenteral nutrition (PN) regimen. The conventional LEs, such as soybean oil (SO)-based emulsions, have caused concerns about the potential adverse effects involving oxidative stress, inflammation, and immune response probably because of undesirable FA composition.

AREAS COVERED

Recently, alternative LEs, optimizing the FA composition with partial substitution of SO with medium-chain triglyceride (MCT), olive oil (OO), and fish oil (FO), have been developed and applied in clinical practice. This review summarizes the characteristics and beneficial clinical effects of alternative parenteral LEs in critically ill, pediatric, and long-term PN patients.

EXPERT OPINION

More clinical data from sufficiently high-powered studies are required to characterize the integral biological properties of alternative LEs for further selection to fit individual needs and disease characteristics. Simultaneously, potential lipid sources with desirable FA compositions and biological properties should be selected to develop new therapeutic LEs. As supplements to current parenteral lipids, the new LEs with different therapeutic effects are expected to fit specified subpopulations of patients with different diseases. Great efforts should be devoted to the development of parenteral LEs.