Parenteral fish oil improves outcomes in patients with parenteral nutrition-associated liver injury. Ann Surg. 2009;250:395-402. [PMID: 19661785 DOI: 10.1097/sla.0b013e3181b36657]

The addition of medium-chain triglycerides to a purified fish oil-based diet alters inflammatory profiles in mice

OBJECTIVE

Parenteral nutrition associated liver disease (PNALD) is a deadly complication of long term parenteral nutrition (PN) use in infants. Fish oil-based lipid emulsion has been shown in recent years to effectively treat PNALD. Alternative fat sources free of essential fatty acids have recently been investigated for health benefits related to decreased inflammatory response. We hypothesized that the addition of medium-chain triglycerides (MCT) to a purified fish oil-based diet would decrease the response to inflammatory challenge in mice, while allowing for sufficient growth and development.

MATERIALS/METHODS

Six groups of ten adult male C57/Bl6 mice were pair-fed different dietary treatments for a period of twelve weeks, varying only in fat source (percent calories by weight): 10.84% soybean oil (SOY), 10% coconut oil (HCO), 10% medium-chain triglycerides (MCT), 3% purified fish oil (PFO), 3% purified fish oil with 3% medium-chain triglycerides (50:50 MCT:PFO) and 3% purified fish oil with 7.59% medium-chain triglycerides (70:30 MCT:PFO). An endotoxin challenge was administered to half of the animals in each group at the completion of dietary treatment.

RESULTS

All groups demonstrated normal growth throughout the study period. Groups fed MCT and HCO diets demonstrated biochemical essential fatty acid deficiency and decreased IL-6 and TNF-α response to endotoxin challenge. Groups containing PFO had increased inflammatory response to endotoxin challenge, and the addition of MCT to PFO mitigated this inflammatory response.

CONCLUSION

These results suggest that the addition of MCT to PFO formulations may decrease the host response to inflammatory challenge, which may pose potential for optimized PN formulations. Inclusion of MCT in lipid emulsions given with PN formulations may be of use in therapeutic interventions for disease states resulting from chronic inflammation.

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.

Effect of an Olive Oil-Based Lipid Emulsion Compared With a Soybean Oil-Based Lipid Emulsion on Liver Chemistry and Bile Acid Composition in Preterm Infants Receiving Parenteral Nutrition: A Double-Blind, Randomized Trial

BACKGROUND

The pathogenesis of parenteral nutrition (PN)-associated liver dysfunction is multifactorial. Lipid emulsions may be one of the putative mechanisms. Our aim was to comparatively assess the effect of parenteral olive oil- and soybean oil-based lipid emulsions on liver chemistry and bile acid composition in preterm infants.

METHODS

We performed a double-blind, randomized clinical study in which 103 preterm infants were randomly assigned to PN using either soybean oil-based lipid emulsion (SO; n = 51) or olive oil (OO)-based lipid emulsion (OO; n = 52). The primary end point was liver chemistry. The secondary end point was the plasma bile acid composition.

RESULTS

One hundred infants completed this study. In the SO group, the serum direct bilirubin was significantly higher after PN for 7 days compared with the OO group. Bile acids increased over time in both treatment groups. However, specific differences in the change in bile acid composition over time were noted between groups.

CONCLUSIONS

Differences in direct bilirubin and bile acid composition were observed over time between the 2 groups. Considering the long-term use of lipid emulsions in higher risk babies, these findings might be useful for understanding the pathogenesis of PN-associated liver dysfunction.

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.

Proceedings From FDA/A.S.P.E.N. Public Workshop: Clinical Trial Design for Intravenous Fat Emulsion Products, October 29, 2013

The development of intravenous fat emulsion (IVFE) is the culmination of physiological, biochemical, nutritional, and medical scientific advancements. IVFEs have the ability to deliver critical nutritional substrates to the patient. Recent literature purports that they may also play roles in modulation of immune functionality and pulmonary physiology, but data supporting these potential benefits are limited. While soybean-based IVFEs have comprised the dominant fat in U.S. markets, a number of other novel IVFEs may prove to optimize the care of children and adults in both hospitalized and home settings. The October 2013 U.S. Food and Drug Administration (FDA)/American Society for Parenteral and Enteral Nutrition (A.S.P.E.N.) Public Workshop brought together scientists, researchers, and clinical experts to present updated clinical perspectives of IVFEs, including historical development, current state of usage throughout the world, and considerations for the regulatory approval of new IVFEs in the United States.

Parenteral nutrition-associated liver injury and increased GRP94 expression prevented by ω-3 fish oil-based lipid emulsion supplementation

OBJECTIVE

Parenteral nutrition in infants with gastrointestinal disorders can be lifesaving, but it is also associated with parenteral nutrition-associated liver disease. We investigated the effects of incorporating ω-3 fish oil in a parenteral nutrition mixture on signs of parenteral nutrition-associated liver disease and explored the mechanism involved in this process.

METHODS

Seven-day-old New Zealand rabbits were divided into 3 groups of 8, and for 1 week they were infused via the right jugular vein with standard total parenteral nutrition with soybean oil (TPN-soy) or TPN with ω-3 fish oil-based lipid emulsion (TPN-FO), or naturally nursed with rabbit milk (control). Serum and liver tissues were analyzed for serological indicators and pathology, respectively. Reverse-transcriptase polymerase chain reaction was used to evaluate the messenger RNA levels of the endoplasmic reticulum stress chaperone protein glucose-regulated protein 94 (GRP94) in liver tissues and GRP94 protein levels were compared through immunohistochemistry and Western blot assays.

RESULTS

TPN-soy animals had significantly higher serum total bilirubin, direct bilirubin, and γ-glutamyl transpeptidase and lower serum albumin than the controls (P < 0.01, each) or the TPN-FO group, which were similar to the controls (P < 0.01 cf. TPN). Damage to liver tissues of the TPN-FO group was much less than that of the TPN-soy group. GRP94 messenger RNA and protein levels in liver tissues of TPN-soy animals were significantly higher than that of the controls or TPN-FO rabbits, which were similar to the controls.

CONCLUSIONS

Incorporating ω-3 fish oil in parenteral nutrition emulsion greatly prevented liver dysfunction and liver tissue damage in week-old rabbit kits, possibly by preventing endoplasmic reticulum stress.

Recent advances in the management of pediatric intestinal failure

Intestinal failure is a chronic condition in which the intestinal tract has lost most of its function. Prognosis depends on the severity and underlying etiologies. Although many patients survive under parenteral nutrition support, they often suffer from fatal complications such as progressive cholestasis and frequent sepsis. In addition, to decide the proper time to refer selected patients to bowel transplantation remains difficult. A noninvasive biomarker developed to evaluate functional enterocyte mass and the extent of intestinal adaptation is plasma citrulline level. It is shown that serum citrulline correlates with small bowel length, oral tolerance, and parenteral nutrition dependency. Recent evidence has revealed that the use of fish oil containing lipid emulsions to substitute traditional soybean-based formula may reverse a patient's cholestasis and improve lipid profiles. A new method used to prevent catheter-related bloodstream infection is ethanol lock therapy. With both antimicrobial and fibrinolytic activities, studies have shown that ethanol locks can effectively decrease catheter infection and replacement rate with no known resistance reported. As part of intestinal rehabilitation, auxiliary surgeries such as longitudinal intestinal lengthening and tailoring, serial transverse enteroplasty, and tapering enteroplasty can be beneficial for selected patients before bridging to bowel transplantation. With the introduction of these new medical and surgical modalities, patients with intestinal failure are having better outcomes than in the past.

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.

A.S.P.E.N. clinical guidelines: support of pediatric patients with intestinal failure at risk of parenteral nutrition-associated liver disease

BACKGROUND

Children with severe intestinal failure and prolonged dependence on parenteral nutrition are susceptible to the development of parenteral nutrition-associated liver disease (PNALD). The purpose of this clinical guideline is to develop recommendations for the care of children with PN-dependent intestinal failure that have the potential to prevent PNALD or improve its treatment.

METHOD

A systematic review of the best available evidence to answer a series of questions regarding clinical management of children with intestinal failure receiving parenteral or enteral nutrition was undertaken and evaluated using concepts adopted from the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) Working Group. A consensus process was used to develop the clinical guideline recommendations prior to external and internal review and approval by the American Society for Parenteral and Enteral Nutrition Board of Directors.

QUESTIONS

(1) Is ethanol lock effective in preventing bloodstream infection and catheter removal in children at risk of PNALD? (2) What fat emulsion strategies can be used in pediatric patients with intestinal failure to reduce the risk of or treat PNALD? (3) Can enteral ursodeoxycholic acid improve the treatment of PNALD in pediatric patients with intestinal failure? (4) Are PNALD outcomes improved when patients are managed by a multidisciplinary intestinal rehabilitation team?

Hepatic explant pathology of pediatric intestinal transplant recipients previously treated with omega-3 fatty acid lipid emulsion

OBJECTIVE

To evaluate and compare the biochemical and histologic effect of parenteral fish oil lipid emulsion that is rich in omega-3 polyunsaturated fatty acids (O3FAs), Omegaven (Fresenius Kabi AG, Bad Homburg, Germany) with standard omega-6 polyunsaturated fatty acid (O6FA) parenteral nutrition.

STUDY DESIGN

Comparison of hepatic explant pathology and biochemical outcome on pediatric patients with intestinal failure treated with either parental O3FA or O6FA who had received a liver-inclusive intestine transplant.

RESULTS

Seven liver-inclusive intestinal transplants were performed in 7 patients who received O3FA for a mean of 62% ± 13% of total patient life-span (16.1 ± 7.0 months) before transplant. Median total bilirubin fell from 6.9 mg/dL at the start of treatment to 0.7 mg/dL at the time transplant (P < .02), which was a significant decrease compared with the similarly matched O6FA cohort (P = .012). All 7 of the 03FA-treated patients received a liver-inclusive intestinal transplant had advanced fibrosis (stage 3 or 4) noted on explant pathologic examination, despite a resolution of cholestasis at the time of transplant. Histologic inflammatory scores were lower (P = .056) in the 03FA group with similar degrees of advanced fibrosis as in the O6FA group.

CONCLUSIONS

In a matched comparison of patients undergoing intestinal transplantation with a history of extended O3FA lipid emulsion therapy that successfully reversed hyperbilirubinemia, significant hepatic fibrosis was present in the explanted livers despite a reduction in inflammation. This result confirms concern that the use of O3FA may have a limited role in altering the development of hepatic fibrosis from parenteral nutrition.

Low-Dose Intravenous Soybean Oil Emulsion for Prevention of Cholestasis in Preterm Neonates

BACKGROUND

Premature infants depend on intravenous fat emulsions to supply essential fatty acids and calories. The dose of soybean-based intravenous fat emulsions (S-IFE) has been associated with parenteral nutrition (PN)-associated liver disease. This study's purpose was to determine if low-dose S-IFE is a safe and effective preventive strategy for cholestasis in preterm neonates.

MATERIALS AND METHODS

This is a multicenter randomized controlled trial in infants with a gestational age (GA) ≤29 weeks. Patients <48 hours of life were randomized to receive a low (1 g/kg/d) or control dose (approximately 3 g/kg/d) of S-IFE. The primary outcome was cholestasis, defined as a direct bilirubin ≥15% of the total bilirubin at 28 days of life (DOL) or full enteral feeds, whichever was later, after 14 days of PN. Secondary outcomes included growth, length of hospital stay, death, and major neonatal morbidities.

RESULTS

In total, 136 neonates (67 and 69 in the low and control groups, respectively) were enrolled. Baseline characteristics were similar for the 2 groups. When the low group was compared with the control group, there was no difference in the primary outcome (69% vs 63%; 95% confidence interval, -0.1 to 0.22; P = .45). While the low group received less S-IFE and total calories over time compared with the control group (P < .001 and P = .03, respectively), weight, length, and head circumference at 28 DOL, discharge, and over time were not different (P > .2 for all).

CONCLUSION

Compared with the control dose, low-dose S-IFE was not associated with a reduction in cholestasis or growth.

Relationship Between Triglyceride Tolerance, Body Mass Index, and Fat Depots in Hospitalized Patients Receiving Parenteral Nutrition

BACKGROUND

Hypertriglyceridemia has been associated with adverse outcomes in patients receiving intravenous fat emulsions (IVFEs), but little is known about its prevalence and causes.

MATERIALS AND METHODS

The study investigated whether a relationship exists between body mass index (BMI) and triglyceride tolerance in parenterally fed patients. We conducted a retrospective analysis of 287 adults receiving parenteral nutrition to determine whether patients with very low BMI (VLBMI, <16 kg/m(2)) tolerate IVFEs better than do patients with low BMI (LBMI, 16-18.4 kg/m(2)), normal-weight patients (NBMI, 18.5-24.9 kg/m(2)), and overweight/obese patients (HBMI, ≥25 kg/m(2)).

RESULTS

The median triglyceride concentration during IVFE was significantly lower in VLBMI patients at 107 mg/dL compared with 124 mg/dL in non-VLBMI patients (P = .016), despite higher lipid infusion rates in the VLBMI group. There was a significant association between triglycerides and BMI in the aggregate cohort (R = 0.2375, P < .0001), with the highest frequency of hypertriglyceridemia occurring in HBMI patients despite relatively lower lipid and energy supply. In a subset of VLBMI patients (n = 36) who had an abdominal computed tomography scan, there was 25- to 100-fold variability in the size of the abdominal adipose tissue depots. In this subgroup, triglyceride concentrations correlated with visceral fat but not subcutaneous abdominal fat.

CONCLUSIONS

In summary, patients with VLBMI have lower triglyceride concentrations during IVFEs than do other individuals, but there is considerable variability in triglycerides and body fat in this group. Caution should be employed with the use of IVFEs, especially in HBMI patients.

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.

The effect of docosahexaenoic acid on bone microstructure in young mice and bone fracture in neonates

BACKGROUND

As low bone mineral density is a risk factor for fracture in childhood, optimizing age appropriate bone mass is recommended and might lower the impact of bone loss related to age. Consumption of omega-3 polyunsaturated fatty acids (PUFAs), including eicosapentaenoic and docosahexaenoic (DHA) acids have been shown to beneficially modulate bone metabolism. The objective of this study was to determine the incidence of fracture in neonates receiving a fish compared with soybean oil-based intravenous lipid emulsion and evaluate the effect of varying dietary omega-3 PUFA consumption on growing bone in young mice.

MATERIALS AND METHODS

Eligibility criteria for the clinical study included gestational age ≤37 wk and parenteral nutrition-dependence for ≥4 wk. Radiographs were reviewed after lipid initiation to identify radiologic bone fracture. The animal study evaluated female C57/Bl6 mice randomized into one of five groups from age 3-12 wk, at which time femurs were harvested for micro-computed tomography and light microscopy analysis.

RESULTS

A lower incidence of bone fracture was found in neonates maintained on fish compared with soybean oil. In the animal study, findings suggest the DHA diet provides the best protection against trabecular bone loss as evidenced by increased bone volume fraction, increased trabecular number, and decreased trabecular separation on micro-computed tomography. These protective effects appeared to affect the bone microstructure alone.

CONCLUSIONS

The lower fracture risk observed in fish oil fed neonates in combination with the protective effects of DHA observed in the femurs of young C57/BL6 mice suggest an important role for omega-3 PUFAs on bone growth.

Growth and fatty acid profiles of VLBW infants receiving a multicomponent lipid emulsion from birth

OBJECTIVES

Very-low-birth-weight (VLBW) infants are dependent on parenteral nutrition after birth. A parenteral lipid emulsion with a multicomponent composition may improve growth and neurodevelopment and may prevent liver injury, which is often observed in association with long-term parenteral nutrition with pure soybean oil. Our aim was to evaluate the safety and efficacy of a multicomponent lipid emulsion containing 30% soybean oil, 30% medium-chain triacylglycerol, 25% olive oil, and 15% fish oil compared with a conventional pure soybean oil emulsion in VLBW infants.

METHODS

We conducted a double-blind randomized controlled trial in VLBW infants randomized to parenteral nutrition with the multicomponent (study group) or pure soybean oil emulsion (control group) from birth at a dose of 2 to 3 g · kg(-1) · day(-1) until the infants were receiving full enteral nutrition. We assessed efficacy by growth rates and measuring plasma fatty acid profiles (representative subset). Safety was evaluated by assessing hematologic and biochemical parameters, potentially harmful phytosterol concentrations (same subset), and clinical neonatal outcome parameters.

RESULTS

Ninety-six infants were included (subsets n = 21). The multicomponent emulsion was associated with higher weight and head circumference z scores during admission. Plasma eicosapentaenoic acid and docosahexaenoic acid concentrations were higher in the study group. The hematological, biochemical, and neonatal outcomes were not different between groups, whereas the plasma concentrations of phytosterols were higher in the control group.

CONCLUSIONS

The multicomponent lipid emulsion was well tolerated and associated with improved growth and higher plasma fatty acid profiles in VLBW infants in comparison with the pure soybean oil emulsion.

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.

Preventive effects of omega-3 fish oil emulsions on parenteral nutrition-associated liver disease

AIM: To determine the efficacy of omega-3 fish oil-based intravenous lipid emulsion in the prevention of parenteral nutrition (PN)-associated liver disease (PNALD).

METHODS: Seventy-six patients who required long-term PN treatment were randomly divided into a control group (soybean-based lipid emulsion group, n = 37) and a study group (omega-3 fish oil-based emulsion group, n = 39). Omega-3 fish oil emulsions were given at 100 mL/d to the study group. The levels of serum albumin, liver function parameters and bilirubin were compared between the two groups.

RESULTS: After 30 d of PN treatment, the morbidity rate of parenteral nutrition-associated liver disease (PNALD) was significantly improved in the study group, compared to the control group (2.6% vs 21.6%, χ² = 6.60, P = 0.01). The levels of serum total bilirubin (14.6 µmol/L ± 7.4 µmol/L vs 41.8 µmol/L ± 29.7 µmol/L, t = 5.56, P < 0.001) and direct bilirubin (5.9 µmol/L ± 2.8 µmol/L vs 27.8 µmol/L ± 27.6 µmol/L, t = 4.01, P < 0.001), and aminotransferase (P < 0.001) had a significant decrease in the study group compared with the control group.

CONCLUSION: Omega-3 fish oil emulsions may be effective in the prevention of PNALD in adults.

Review of macronutrients in parenteral nutrition for neonatal intensive care population

Parenteral nutrition (PN) has become essential in the management of sick and growing newborn populations in the NICU. In the past few decades, PN has become fundamental in the nutritional management of the very low birth weight infant (<1,500 g).1 Although the components in PN are commonly determined and ordered by the physician or neonatal nurse practitioner provider, the NICU nurse is responsible for confirming the components in the daily PN prior to infusion and is responsible for maintaining the infusion of PN. Nurses should understand the nutritional components of PN as well as the indications, side effects, and infusion limitations of each component. The purpose of this article is to review the macronutrients in PN, including carbohydrates, protein, and fat. A subsequent article will review the micronutrients in PN, including electrolytes, minerals, and vitamins.

Liver disease secondary to intestinal failure

IFALD is a common and potentially life-threatening condition for patients with SBS requiring long-term PN. There exists the potential for decreasing its incidence by optimizing the composition and the rate of infusion of parenteral solutions, by advocating a multidisciplinary approach, and by early referral for intestinal-liver transplantation to ensure long-term survival of patients with SBS.

Fish oil-based lipid emulsions in the treatment of parenteral nutrition-associated liver disease: an ongoing positive experience

We previously reported the beneficial effect of fish oil-based lipid emulsions (FOLEs) as monotherapy in the treatment of parenteral nutrition-associated liver disease (PNALD). In this report, we share our ongoing experience at Texas Children's Hospital, Houston, Texas in the use of FOLE in treatment of PNALD as presented at the 2013 Experimental Biology meeting. We describe the findings of a single center, prospective, observational study of infants <6 mo of age with PNALD who received parenteral FOLE as monotherapy. A total of 97 infants received FOLE under the compassionate-use protocol for the treatment of PNALD. Eighty-three (86%) survived with resolution of cholestasis and 14 (14%) died. The median conjugated bilirubin (CB) concentration at the initiation of FOLE therapy was 4.8 mg/dL (range 2.1-26). The median time to resolution of cholestasis was 40 d (range 3-158). Compared with infants with mild cholestasis (CB of 2.1-5 mg/dL at the initiation of FOLE), nonsurvivors were significantly more premature and took longer to resolve their cholestasis. Gestational age at birth correlated inversely with CB at the beginning of FOLE and peak CB. Infants with an initial CB >10 mg/dL had a higher mortality rate than infants with an initial CB <5 mg/dL (35% vs. 6%; P < 0.05). Our experience with the use of FOLE in PNALD continues to be encouraging. Prematurity continues to be a major determinant in mortality and severity of cholestasis. This calls for further controlled studies designed to optimize dose and timing of intervention in the use of FOLE in neonates.

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.

Serial transverse enteroplasty allows children with short bowel to wean from parenteral nutrition

OBJECTIVE

To analyze the effects of serial transverse enteroplasty (STEP) on parenteral and enteral calories in children with short bowel syndrome, and examine short- and long-term complications.

STUDY DESIGN

A retrospective analysis of prospectively-collected data from a large single center cohort of patients undergoing STEP procedure was analyzed. Baseline demographic and clinical information, operative data, and short- and long-term complications were recorded. Detailed growth and nutritional data were obtained for 6 months prior and 12 months following STEP procedure.

RESULTS

Sixty-eight procedures were performed in 51 patients over a 68-month period. Median bowel length at first STEP was 51 cm with a median length gain of 54%. Repeat STEP patients had longer initial length (77 cm) and reduced length gain (20%). Operative times and blood loss were low, with few complications. Parenteral calorie requirement was stable or rising for 6 months prior to STEP, but decreased to median <20 kCal/kg/d at 1 year postop. Longer length gains were associated with higher risk of stricture formation. Seven children were transplanted, and 60% of nontransplanted children were enterally independent, with the remainder making ongoing progress; 48/51 children are alive at a median of 39 months follow-up.

CONCLUSIONS

STEP is shown to be safe, well tolerated, and to have definitive benefit in reducing parenteral calorie requirements over the first year following the procedure. It has an important role in achieving enteral independence in children with short bowel syndrome.

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.

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.

Intravenous fish oil lipid emulsion promotes a shift toward anti-inflammatory proresolving lipid mediators

Parenteral nutrition (PN)-associated liver disease (PNALD) is a life-threatening complication of the administration of PN. The development of PNALD may be partly due to the composition of the lipid emulsion administered with PN: soybean oil-based lipid emulsions (SOLE) are associated with liver disease, while fish oil-based lipid emulsions (FOLE) are associated with prevention and improvement of liver disease. The objective of this study was to determine how the choice of lipid emulsion modified the production of bioactive lipid mediators (LMs). We utilized a mouse model of steatosis to study the differential effect of FOLE and SOLE. We subsequently validated these results in serum samples from a small cohort of human infants transitioning from SOLE to FOLE. In mice, FOLE was associated with production of anti-inflammatory, proresolving LMs; SOLE was associated with increased production of inflammatory LMs. In human infants, the transition from SOLE to FOLE was associated with a shift toward a proresolving lipidome. Together, these results demonstrate that the composition of the lipid emulsion directly modifies inflammatory homeostasis.

Life-threatening risk factors and the role of intestinal transplantation in patients with intestinal failure

PURPOSE

We elucidated the life-threatening risk factors for intestinal failure (IF) and characterized the role of intestinal transplantation (ITx) in affected patients.

METHODS

We conducted a retrospective review of 38 patients with short bowel (SB) and 19 with motility disorders (MD). The SB patients were divided into three categories according to the length of their residual small bowel and the presence of the ileocecal valve. The four disease subcategories were grouped into two categories: low-risk category (mild and moderated SB) and high-risk category (extensive SB and MD). The age at the introduction of parenteral nutrition (PN) was <1 year in 50 patients (infant group, IG) and 1-15 years in 7 patients (pediatric group, PG).

RESULTS

Enteral autonomy was rarely achieved in the high-risk category (p < 0.0001). IG was associated with a higher incidence of developing intestinal failure-associated liver disease (IFALD) (p = 0.004). Eight patients died, due to IFALD in four, sepsis in three and acute heart failure in one. Twenty-eight patients (49 %) are currently alive without PN, including four after ITx.

CONCLUSION

The treatment of high-risk IF is still challenging. Inclusion of ITx in appropriate timing, along with aggressive medical, nutritional and surgical management, may reduce advanced morbidity and mortality of high-risk IF.

Treatment of parenteral nutrition-associated liver disease: the role of lipid emulsions

Parenteral nutrition is a life-saving therapy for infants with intestinal failure. However, long-term parenteral nutrition carries the risk of progressive liver disease. Substantial data has implicated components of parenteral soybean oil in the pathogenesis of parenteral nutrition-associated liver disease (PNALD). Elevated serum concentrations of phytosterols, an abundance of omega-6 polyunsaturated fatty acids, and a relative paucity of α-tocopherol have been associated with the risk of cholestasis and hepatic injury observed in PNALD. Currently available treatment strategies include the reduction of the dose of administered parenteral soybean oil and/or the replacement of parenteral soybean oil with alternative parenteral lipid emulsions. The purpose of this review is to provide an overview of the pathogenetic mechanisms associated with the development of PNALD and the data evaluating currently available treatment strategies.

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.

Pediatric intestinal failure-associated liver disease is reversed with 6 months of intravenous fish oil

BACKGROUND

Studies have suggested that when intravenous (IV) soybean oil (SO) is replaced with fish oil (FO), direct hyperbilirubinemia is more likely to resolve. The necessary duration of FO has not been established. This study seeks to determine if 24 weeks of FO is an effective and safe therapy for intestinal failure-associated liver disease (IFALD).

MATERIALS AND METHODS

This is a clinical trial using patients with IFALD between the ages of 2 weeks and 18 years. SO was replaced with FO (1 g/kg/d) in 10 patients who were receiving most of their calories from parenteral nutrition (PN). Patients were compared with 20 historic controls receiving SO. SO for both groups was prescribed by the primary medical team at variable doses. The primary outcome was time to reversal of cholestasis. Secondary outcomes were death, transplant, and full enteral feeds. Safety measurements included growth, essential fatty acid deficiency, and laboratory markers to assess bleeding risk.

RESULTS

The Kaplan-Meier method estimated that 75% in the FO group would experience resolution of cholestasis by 17 weeks vs 6% in the SO group (P < .0001). When compared with the SO group, the FO group had decreased serum direct bilirubin concentrations at weeks 8 (P = .03) and 12, 16, 20, and 24 weeks (P < .0001). Although length z score at the end of the study increased in the FO group compared with baseline (P = .03), there were no significant differences in other outcomes.

CONCLUSIONS

A limited duration of FO appears to be safe and effective in reversing IFALD.

Incidence, prevention, and treatment of parenteral nutrition-associated cholestasis and intestinal failure-associated liver disease in infants and children: a systematic review

BACKGROUND

Cholestasis is a significant life-threatening complication in children on parenteral nutrition (PN). Strategies to prevent/treat PN-associated cholestasis (PNAC) and intestinal failure-associated liver disease (IFALD) have reached moderate success with little supporting evidence. Aims of this systematic review were (1) to determine the incidence of PNAC/IFALD in children receiving PN for ≥ 14 days and (2) to review the efficacy of measures to prevent/treat PNAC/IFALD.

METHODS

Of 4696 abstracts screened, 406 relevant articles were reviewed, and studies on children with PN ≥ 14 days and cholestasis (conjugated bilirubin ≥ 2 mg/dL) were included. Analyzed parameters were (1) PNAC/IFALD incidence by decade and by PN length and (2) PNAC/IFALD prevention and treatment (prospective studies).

RESULTS

Twenty-three articles (3280 patients) showed an incidence of 28.2% and 49.8% of PNAC and IFALD, respectively, with no evident alteration over the last decades. The incidence of PNAC was directly proportional to the length of PN (from 15.7% for PN ≤ 1 month up to 60.9% for PN ≥ 2 months; P < .0001). Ten studies on PNAC met inclusion criteria. High or intermediate-dose of oral erythromycin and aminoacid-free PN with enteral whey protein gained significant benefits in preterm neonates (P < .05, P = .003, and P < .001, respectively). None of the studies reviewed met inclusion criteria for treatment.

CONCLUSIONS

The incidence of PNAC/IFALD in children has no obvious decrease over time. PNAC is directly correlated to the length of PN. Erythromycin and aminoacid-free PN with enteral whey protein have shown to prevent PNAC in preterm neonates. There is a lack of high-quality prospective studies, especially on IFALD.

Indications for intestinal transplantation: recognizing the scope and limits of total parenteral nutrition

Total parenteral nutrition (TPN) is currently the treatment of choice for patients with intestinal failure. Intestinal failure in adults is mostly due to short bowel syndrome, which is most often caused by ischemia and Crohn's disease. However, TPN fails in a substantial number of cases. For patients with TPN failure, intestinal transplantation (ITx) may be offered as a treatment. TPN failure is considered to be present either if nutrition itself is not possible or if complications of TPN occur. These complications can, for example, originate from recurrent line infections or thrombosis. As TPN is usually a lifelong therapy and is associated with substantial impairment of the quality of life, the tolerance of each patient to this procedure is another important consideration in the decision making about whether to perform transplantation. The survival rates of intestinal transplant recipients have now reached the same level as that of recipients of other solid organ transplants. A five-yr survival of up to 80% has been reported in specialized centers, whereas registry data show rates of <80%. Although in about one-third of patients, isolated ITx is sufficient, patients with concurrent liver disease (mostly due to TPN) benefit from combined intestinal and liver transplantation. In some cases, multivisceral transplantation is necessary. Here, we review the current indications for ITx with a special focus on TPN.

Plasma fatty acids in premature infants with hyperbilirubinemia: before-and-after nutrition support with fish oil emulsion

Infants who are dependent on parenteral nutrition (PN) sometimes develop PN-associated cholestasis (PNAC). A compassionate use protocol, approved by the U.S. Food and Drug Administration and the institutional review board, guided enrollment of hospitalized infants with PNAC (<1 year of age, PN dependence for >3 weeks). Plasma concentrations of essential fatty acids were monitored before and after a soybean-based PN lipid, infused at 3 g/kg body weight/d, was replaced by an experimental fish oil-based intravenous fat emulsion (FO-IVFE) at 1.0 g/kg/d. All participants were born premature (n = 10; 20% male). At enrollment, infants were (mean ± SD) 86.5 ± 53.5 days of life and weighed 2.24 ± 0.87 kg; direct bilirubin was 5.5 ± 1.3 mg/dL. After treatment, blood concentrations significantly increased from baseline (P < .017) for circulating eicosapentaenoic acid (6.3 ± 3.0 to 147.8 ± 53.1 µg/mL), docosahexaenoic acid (20.7 ± 6.5 to 163.7 ± 43.4 µg/mL), pristanic acid (0.01 ± 0.01 to 0.17 ± 0.03 µg/mL), and phytanic acid (0.06 ± 0.03 to 0.64 ± 0.15 µg/mL). In contrast, total plasma ω-6 fatty acids (including linoleic acid) decreased (P < .017). The triene/tetraene ratio remained below the threshold value of 0.2 that defines ω-6 deficiency. No adverse effects were observed attributable to FO-IVFE. Discontinuation of FO-IVFE was typically due to infants (body weight 3.76 ± 1.68 kg) transitioning to enteral feeding rather than for resolution of hyperbilirubinemia (direct bilirubin 7.9 ± 4.8 mg/dL). These exploratory results suggest that FO-IVFE raises circulating ω-3 fatty acids in premature infants without development of ω-6 deficiency in the 8.3 ± 5.8-week time frame of this study.

A comparison of 2 intravenous lipid emulsions: interim analysis of a randomized controlled trial

OBJECTIVE

To assess the safety and efficacy of a fish oil-based intravenous fat emulsion (FIFE) in reducing the incidence of cholestasis in neonates compared with the traditional soybean oil-based intravenous fat emulsion (SIFE).

METHODS

A double-blind randomized controlled trial was conducted. Nineteen neonates were enrolled (10 SIFE; 9 FIFE). Nutrition assessments and laboratory studies were serially obtained for the duration of PN support or until 6 months' corrected gestational age. Neurodevelopmental outcomes were assessed at 6 and 24 months' corrected age.

RESULTS

There were no differences between groups in demographic characteristics, with an overall median age of 2 days, gestational age of 36 weeks, and birth weight of 2410 g. There were no differences between groups in baseline laboratory values other than alkaline phosphatase (lower in the FIFE group) or in the duration of parenteral nutrition (PN), amount of enteral intake, or the number of operative procedures. The incidence of cholestasis among enrolled patients was significantly lower than expected, resulting in early study termination and an inability to assess for differences in the incidence of cholestasis. The FIFE was associated with no increased risk of growth impairment, coagulopathy, infectious complications, hypertriglyceridemia, or adverse neurodevelopmental outcomes. No patient developed essential fatty acid deficiency.

CONCLUSION

The FIFE at 1 g/kg/d was well tolerated in the neonates recruited for this study. Given the necessary early termination of this study, a follow-up trial with revised eligibility criteria is necessary to determine whether the provision of FIFE decreases the incidence of PN-cholestasis compared with the traditional SIFE.

Effect of decreased parenteral soybean lipid emulsion on hepatic function in infants at risk for parenteral nutrition-associated liver disease: a pilot study

PURPOSE

We performed a pilot trial to compare reduced dose versus standard soybean lipid emulsion in neonates at risk for parenteral nutrition-associated liver disease.

METHODS

A prospective randomized controlled trial was performed (2009-2011) enrolling surgical patients ≥ 26 weeks' gestation anticipated to require >50% of daily caloric intake from parenteral nutrition (PN) for at least 4 weeks. Randomization occurred into either reduced (1.0 g/kg/day) or standard (3g/kg/day) groups. Co-primary outcomes for interpretation of the results were conjugated bilirubin and total bile acids. Additional outcomes included ALT, AST, GGT, alkaline phosphatase, growth, and essential fatty acid levels. Outcomes were compared between treatment groups using Wilcoxon rank sums tests.

RESULTS

Twenty-eight patients (47% enrollment rate) were included in the study with an average treatment duration of 5.4 weeks. Groups had similar PN calories and protein intake throughout the study. Total increase from baseline was smaller in the reduced vs. standard group for conjugated bilirubin (p=0.04) and total bile acids (p=0.02). Weight z-score increased more in the standard group, and no patient experienced essential fatty acid deficiency.

CONCLUSION

Markers of cholestasis rose at a slower rate using reduced lipid doses. This pilot study demonstrates feasibility and need for a larger study evaluating the effects of reduced lipids in patients at risk for developing parenteral nutrition-associated liver disease.

A metabolomic analysis of two intravenous lipid emulsions in a murine model

Background

Parenteral nutrition (PN), including intravenous lipid administration, is a life-saving therapy but can be complicated by cholestasis and liver disease. The administration of intravenous soy bean oil (SO) has been associated with the development of liver disease, while the administration of intravenous fish oil (FO) has been associated with the resolution of liver disease. The biochemical mechanism of this differential effect is unclear. This study compares SO and FO lipid emulsions in a murine model of hepatic steatosis, one of the first hits in PN-associated liver disease.

Methods

We established a murine model of hepatic steatosis in which liver injury is induced by orally feeding mice a PN solution. C57BL/6J mice were randomized to receive PN alone (a high carbohydrate diet (HCD)), PN plus intravenous FO (Omegaven®; Fresenius Kabi AG, Bad Homburg VDH, Germany), PN plus intravenous SO (Intralipid®; Fresenius Kabi AG, Bad Homburg v.d.H., Germany, for Baxter Healthcare, Deerfield, IL), or a chow diet. After 19 days, liver tissue was harvested from all animals and subjected to metabolomic profiling.

Results

The administration of an oral HCD without lipid induced profound hepatic steatosis. SO was associated with macro- and microvesicular hepatic steatosis, while FO largely prevented the development of steatosis. 321 detectable compounds were identified in the metabolomic analysis. HCD induced de novo fatty acid synthesis and oxidative stress. Both FO and SO relieved some of the metabolic shift towards de novo lipogenesis, but FO offered additional advantages in terms of lipid peroxidation and the generation of inflammatory precursors.

Conclusions

Improved lipid metabolism combined with reduced oxidative stress may explain the protective effect offered by intravenous FO in vivo.

The effect of varying ratios of docosahexaenoic acid and arachidonic acid in the prevention and reversal of biochemical essential fatty acid deficiency in a murine model

OBJECTIVE

Essential fatty acids (EFA) are necessary for growth, development, and biological function, and must be acquired through the diet. While linoleic acid (LA) and alpha-linolenic acid (ALA) have been considered the true EFAs, we previously demonstrated that docosahexaenoic acid (DHA) and arachidonic acid (AA) taken together as the sole source of dietary fatty acids can prevent biochemical essential fatty acid deficiency (EFAD). This study evaluates the effect of varying dietary ratios of DHA:AA in the prevention and reversal of biochemical EFAD in a murine model.

METHODS

Using a murine model of EFAD, we provided mice with 2.1% of daily caloric intake in varying DHA:AA ratios (1:1, 5:1, 10:1, 20:1, 200:1, 100:0) for 19 days in association with a liquid high-carbohydrate fat-free diet to evaluate the effect on fatty acid profiles. In a second experiment, we evaluated the provision of varying DHA:AA ratios (20:1, 200:1, 100:0) on the reversal of biochemical EFAD.

RESULTS

Mice provided with DHA and AA had no evidence of biochemical EFAD, regardless of the ratio (1:1, 5:1, 10:1, 20:1, 200:1, 100:0) administered. Biochemical EFAD was reversed with DHA:AA ratios of 20:1, 200:1, and 100:0 following 3 and 5 weeks of dietary provision, although the 20:1 ratio was most effective in the reversal and stabilization of the triene:tetraene ratio.

CONCLUSION

Provision of DHA and AA, at 2.1% of daily caloric intake in varying ratios can prevent biochemical evidence of EFAD and hepatic steatosis over the short-term, with a ratio of 20:1 DHA:AA most effectively reversing EFAD.

Fish oil-based lipid emulsion in the treatment of parenteral nutrition-associated liver disease

PURPOSE OF REVIEW

Parenteral nutrition-associated liver disease (PNALD) is a major cause of morbidity and mortality in the parenteral nutrition-dependent population. Here, we review the most recent literature involving a fish oil-based lipid emulsion (FOLE) and its effects on PNALD.

RECENT FINDINGS

Vegetable oil-based lipid emulsions (VBLEs) contribute to PNALD. This may be due to parenteral phytosterols and/or the presence of pro-inflammatory mediators. Whereas a small reduction in the dose of VBLE does not appear to prevent PNALD, a significant reduction in the dose may reverse PNALD; however, it carries the risk of essential fatty acid deficiency. Furthermore, the impact of extreme lipid restriction on subsequent neurodevelopment is unknown. Combination lipid emulsions containing fish oil are associated with decreased bilirubin levels, though no studies compare these emulsions with the outcomes with FOLE alone. The utility of FOLE in the reversal of PNALD has been demonstrated and its administration does not lead to essential fatty acid deficiency. Furthermore, there is evidence that FOLE may prevent PNALD.

CONCLUSION

FOLE appears to be an efficacious treatment to reverse PNALD. However, more studies are necessary to determine if FOLE might also be beneficial in the prevention of PNALD. Future studies should additionally focus on the preterm infant population, as they represent a major population requiring parenteral nutrition support for survival.

Hepatic fibrosis persists and progresses despite biochemical improvement in children treated with intravenous fish oil emulsion

OBJECTIVES

Intestinal failure-associated liver disease (IFALD) is a multifactorial process, which can culminate in cirrhosis and need for transplantation. Fish oil-based lipid emulsions (FOE) reportedly reverse hyperbilirubinemia, but there are little data on their effect on the histopathology of IFALD.

METHODS

We blindly examined sequential liver biopsy data on 6 children receiving FOE, with scoring of cholestasis, inflammation, fibrosis, and ductal proliferation based on standardized systems. This information was correlated with biochemical and clinical data to determine any possible relations between biologic and histologic improvement.

RESULTS

The median gestational age was 35 weeks, median birth weight 2064 g, and common most reason for intestinal loss was gastroschisis (5/6 children). Median intestinal length was 26 cm beyond the ligament of Treitz and most children had roughly 2 of 3 of their colonic length. It was observed that although hyperbilirubinemia reversed and hepatic synthetic function was preserved across timepoints, fibrosis was persistent in 2 cases, progressive in 3 cases, and regressed in only 1. It remained severe (grade 2 or higher) in 5 of 6 children at last biopsy. Histologic findings of cholestasis improved in all patients and inflammation improved in 5 of 6 children. There were mixed effects on ductal proliferation and steatosis.

CONCLUSIONS

In children treated with FOE, reversal of hyperbilirubinemia is not reflected by a similar histologic regression of fibrosis at the timepoints studied. Children with IFALD should have active ongoing treatment and be considered for early referral to an Intestinal Failure Program even with a normalized bilirubin.

High rates of resolution of cholestasis in parenteral nutrition-associated liver disease with fish oil-based lipid emulsion monotherapy

OBJECTIVE

To determine factors leading to resolution of cholestasis in patients with parenteral nutrition-associated liver disease treated with fish oil-based lipid emulsion (FOLE).

STUDY DESIGN

Prospective observational study of 57 infants <6 months of age with parenteral nutrition-associated liver disease who received parenteral FOLE as monotherapy.

RESULTS

Median gestational age of subjects at birth was 28 weeks (range 22.7-39.5). Median conjugated bilirubin level at initiation of therapy with FOLE was 7.5 mg/dL (range 2.1-25). Resolution of hyperbilirubinemia (conjugated bilirubin <2.0 mg/dL) and survival to hospital discharge occurred in 47 (82.5%) infants. Median number of days to resolution of cholestasis was 35 (range 7-129). Ten infants (17.5%) died. Non-survivors showed a trend towards being more premature than survivors at birth (25.9 vs 29.1 weeks, P = .056). Infants with higher conjugated bilirubin at initiation of therapy (>10.0 compared with <5.0 mg/dL) had longer times to resolution (98 vs 56 days, P < .005). Time to resolution correlated inversely with gestational age at birth (r(2) = 0.14, P = .02) and directly with time to receive 100% calories enterally (r(2) = 0.12, P = .03).

CONCLUSIONS

Younger gestational age infants demonstrated higher degree of cholestasis, longer time to resolution of cholestasis, and increased mortality. Higher levels of cholestasis were associated with longer time to resolution. FOLE monotherapy led to resolution of cholestasis in all surviving infants.

Short bowel syndrome in the NICU

Short bowel syndrome (SBS) is the most common cause of intestinal failure in infants. In neonates and young infants, necrotizing enterocolitis, gastroschisis, intestinal atresia, and intestinal malrotation/volvulus are the leading causes of SBS. Following an acute postsurgical phase, the residual gastrointestinal tract adapts with reorganization of the crypt-villus histoarchitecture and functional changes in nutrient absorption and motility. A cohesive, multidisciplinary approach can allow most neonates with SBS to transition to full enteral feeds and achieve normal growth and development. In this article, the clinical features, management, complications, and prognostic factors in SBS are reviewed.