Parenteral lipid emulsions based on olive oil compared with soybean oil in preterm (<28 weeks' gestation) neonates: a randomised controlled trial

Parenteral lipid emulsions in the preterm infant: current issues and controversies

Parenteral lipid emulsions are a necessary component of nutrition for extremely low gestational age newborns until adequate levels of enteral intake are established. Historically, Intralipid, a 100% soybean oil emulsion, has filled this role. Newer multicomponent lipid emulsions containing a mixture of other oils, including olive oil and fish oil, are now available as options, although the regulatory approval for use in neonates varies worldwide. When dosed at currently published recommendations, each of these lipid emulsions meets total fat and energy requirements without a risk of essential fatty acid deficiency. Thus, when choosing which lipid emulsion to provide, the answer must be based on the metabolic differences induced as a result of these fatty acid-rich emulsions and whether the emulsions provide a health advantage or pose a health risk. The questions of induced fatty acid profiles, health benefit and health risk are discussed sequentially for multicomponent lipid emulsions. Despite the growing acceptance of multicomponent lipid emulsions, there is concern regarding changes in blood fatty acid levels and potential health risk without strong evidence of benefit. There remains no ideal parenteral lipid emulsion option for the preterm infant. Standardising future animal and human studies in lipid delivery with the inclusion of lipid metabolism data will iteratively provide answers to inform the optimal lipid emulsion for the preterm infant.

Parenteral Nutrition and Oxidant Load in Neonates

Neonates with preterm, gastrointestinal dysfunction and very low birth weights are often intolerant to oral feeding. In such infants, the provision of nutrients via parenteral nutrition (PN) becomes necessary for short-term survival, as well as long-term health. However, the elemental nutrients in PN can be a major source of oxidants due to interactions between nutrients, imbalances of anti- and pro-oxidants, and environmental conditions. Moreover, neonates fed PN are at greater risk of oxidative stress, not only from dietary sources, but also because of immature antioxidant defences. Various interventions can lower the oxidant load in PN, including the supplementation of PN with antioxidant vitamins, glutathione, additional arginine and additional cysteine; reduced levels of pro-oxidant nutrients such as iron; protection from light and oxygen; and proper storage temperature. This narrative review of published data provides insight to oxidant molecules generated in PN, nutrient sources of oxidants, and measures to minimize oxidant levels.

Use of Lipids in Neonates Requiring Parenteral Nutrition

Neonates have limited antioxidative capacity and are at increased risk of infection and inflammation-a situation that is exacerbated in preterm neonates. Together, oxidative stress and inflammation are implicated in many serious conditions affecting neonates, such as bronchopulmonary dysplasia and periventricular leukomalacia. Neonates requiring parenteral nutrition have certain nutritional requirements. For example, very long-chain ω-3 polyunsaturated fatty acids (PUFAs) such as docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) are regarded as conditionally essential with critical roles during early retinal and brain development, and may also have other benefits such as anti-inflammatory effects. Because of these factors, the choice of lipid emulsion used as part of parenteral nutrition support may influence clinical outcomes in neonates. There are concerns that lipid emulsions based purely on soybean oil may increase lipid peroxidation, oxidative stress, and inflammation because of their high ω-6 PUFA and low ω-3 PUFA concentrations. Composite fish-oil containing lipid emulsions may provide advantages for neonates owing to their high DHA and EPA content and high antioxidant (α-tocopherol) levels. Here, we discuss clinical trials of lipid emulsions in preterm and term neonatal populations, with a particular emphasis on markers of oxidative stress and DHA and EPA levels. Olive oil/soybean oil lipid emulsions have shown few advantages in neonates over other lipid emulsions. However, compared with either pure soybean or soybean/olive-oil based emulsions, composite fish-oil containing lipid emulsions reduce oxidative stress/lipid peroxidation and also increase DHA and EPA levels. These advantages may translate into clinical benefits for neonates requiring parenteral nutrition.

Oxidative Stress in Preterm Infants: Overview of Current Evidence and Future Prospects

Preterm birth (PTB), defined as parturition prior to 37 weeks of gestation, is the leading cause of morbidity and mortality in the neonatal population. The incidence and severity of complications of prematurity increase with decreasing gestational age and birthweight. The aim of this review study is to select the most current evidence on the role of oxidative stress in the onset of preterm complication prevention strategies and treatment options with pre-clinical and clinical trials. We also provide a literature review of primary and secondary studies on the role of oxidative stress in preterm infants and its eventual treatment in prematurity diseases. We conducted a systematic literature search of the Medline (Pubmed), Scholar, and ClinicalTrials.gov databases, retroactively, over a 7-year period. From an initial 777 articles identified, 25 articles were identified that met the inclusion and exclusion criteria. Of these, there were 11 literature reviews: one prospective cohort study, one experimental study, three case-control studies, three pre-clinical trials, and six clinical trials. Several biomarkers were identified as particularly promising, such as the products of the peroxidation of polyunsaturated fatty acids, those of the oxidation of phenylalanine, and the hydroxyl radicals that can attack the DNA chain. Among the most promising drugs, there are those for the prevention of neurological damage, such as melatonin, retinoid lactoferrin, and vitamin E. The microbiome also has an important role in oxidative stress. In conclusion, the most recent studies show that a strong relationship between oxidative stress and prematurity exists and that, unfortunately, there is still little therapeutic evidence reported in the literature.

Parenteral nutrition and oxidant stress in the newborn: A narrative review

There is strong evidence that oxidant molecules from various sources contaminate solutions of parenteral nutrition following interactions between the mixture of nutrients and some of the environmental conditions encountered in clinical practice. The continuous infusion of these organic and nonorganic peroxides provided us with a unique opportunity to study in cells, in vascular and animal models, the mechanisms involved in the deleterious reactions of oxidation in premature infants. Potential clinical impacts of peroxides infused with TPN include: a redox imbalance, vasoactive responses, thrombosis of intravenous catheters, TPN-related hepatobiliary complications, bronchopulmonary dysplasia and mortality. This is a narrative review of published data.

Lipid emulsions for parenterally fed preterm infants

BACKGROUND

Conventionally used soybean oil-based lipid emulsion (S-LE) have high polyunsaturated fatty acid (PUFA) content and phytosterols that may contribute to adverse effects in preterm infants. The newer lipid emulsions (LE) from different lipid sources are currently available for use in preterm infants.

OBJECTIVES

To compare the safety and efficacy of all LE for parenteral nutrition (PN) in preterm infants (less than 37 weeks' gestation) including preterm infants with surgical conditions or parenteral nutrition-associated liver disease (PNALD)/cholestasis using direct comparisons and pair-wise meta-analyses.

SEARCH METHODS

We used the standard search strategy of Cochrane Neonatal to search the Cochrane Central Register of Controlled Trials (CENTRAL 2018, Issue 5), MEDLINE (1946 to 18 June 2018), Embase (1974 to 18 July 2018), CINAHL (1982 to 18 June 2018), MIDRIS (1971 to 31 May 2018), conference proceedings, trial registries (ClinicalTrials.gov and WHO's Trials Registry and Platform), and reference lists of retrieved articles.

SELECTION CRITERIA

Randomised or quasi-randomised controlled studies in preterm infants with or without surgical conditions or PNALD within the first six months of life.

DATA COLLECTION AND ANALYSIS

Data collection and analysis conformed to the methods of Cochrane Neonatal. We used the GRADE approach to assess the quality of evidence for important outcomes in addition to reporting statistical significance of results.

MAIN RESULTS

We included 29 studies (n = 2037) in this review. LE were classified in three broad groups: 1. all fish oil-containing LE including pure fish oil-LE (F-LE) and multisource LE (e.g. medium-chain triglycerides (MCT)-olive-fish-soybean oil-LE (MOFS-LE), MCT-fish-soybean oil-LE (MFS-LE) and olive-fish-soybean oil-LE (OFS-LE); 2. conventional S-LE; 3. alternative-LE (e.g. MCT-soybean oil-LE (MS-LE), olive-soybean oil-LE and borage oil-based LE).We considered the following broad comparisons: fish oil LE versus non-fish oil LE; fish oil LE versus another fish oil LE; alternative-LE versus S-LE; alternative-LE versus another alternative-LE in preterm infants less than 37 weeks' gestation, preterm infants with surgical conditions and preterm infants with PNALD/cholestasis. Separate subgroup comparisons of each LE preparation were included within these broader groups.Most studies in preterm infants used PN for mean duration of four weeks or less and for longer duration in infants with cholestasis or surgical conditions.We defined the primary outcome of PNALD/cholestasis as conjugated bilirubin (Cbil) 2 mg/dL or greater and resolution of PNALD/cholestasis as Cbil less than 2 mg/dL. There was heterogeneity in definitions used by the included studies with Cbil cut-offs ranging from 17.1 μmol/L (1 mg/dL) up to 50 μmol/L (about 3 mg/dL).In preterm infants, meta-analysis found no evidence of a difference in the incidence of PNALD/cholestasis (Cbil cut-off: 2 mg/dl) between fish oil-LEs and all non-fish oil LEs (typical risk ratio (RR) 0.61, 95% confidence interval (CI) 0.24 to 1.56; typical risk difference (RD) -0.03, 95% CI -0.08 to 0.02; 4 studies; n = 328; low-quality evidence).We also considered an outcome allowing for any definition of PNALD (different Cbil cutoffs). In the meta-analysis for PNALD/cholestasis, using any definition and restricted to low or unclear risk of bias studies, there was no evidence of a difference between fish oil LE and all non-fish oil LE for incidence of cholestasis (typical RR 0.80, 95% CI 0.53 to 1.21; typical RD -0.02, 95% CI -0.05 to 0.02; 10 studies; n = 1024; low-quality evidence). There was no evidence of difference in subgroup meta-analyses of individual LE types in any comparison.In preterm infants with surgical conditions or cholestasis, there was only one small study each reporting no evidence of a difference in incidence or resolution of cholestasis respectively with use of a pure F-LE versus S-LE (using a Cbil cut-off of 2 mg/dL).In preterm infants with PNALD/cholestasis (using any definition), the meta-analysis showed significantly less cholestasis with the use of fish oil-LE compared to S-LE (typical RR 0.54, 95% CI 0.32 to 0.91; typical RD -0.39, 95% CI -0.65 to -0.12; number needed to treat for an additional beneficial outcome (NNTB) 3, 95% CI 2 to 9; 2 studies; n = 40; very low-quality evidence). However, this outcome had a very low number of participants from two small studies with methodological differences, one of which was terminated early, increasing the uncertainty about effect estimates.There were no differences between LE types in pair-wise meta-analyses for growth in preterm infants. There was paucity of studies in preterm infants with surgical conditions or cholestasis to perform meta-analyses for growth and most other outcomes.In the secondary outcomes for preterm infants, there was no difference between fish-oil LE and non-fish oil LE in meta-analysis for severe retinopathy of prematurity (ROP) (stage 3 or greater, or requiring surgery: typical RR 0.80, 95% CI 0.55 to 1.16; typical RD -0.03, 95% CI -0.07 to 0.02; 7 studies; n = 731; very low-quality evidence). There were no differences in the LE types in pair-wise meta-analyses for death, bronchopulmonary dysplasia (BPD), ventilation duration, patent ductus arteriosus, sepsis, necrotising enterocolitis, intraventricular haemorrhage, periventricular leukomalacia, jaundice, hyperglycaemia, hypertriglyceridaemia, intrahepatocellular lipid content and conjugated bilirubin levels in any comparison.In surgical infants, one study (n = 19) reported no differences in death, sepsis rates, Cbil and neurodevelopmental outcomes with pure F-LE versus S-LE.In infants with cholestasis, there were no evidence of differences in death or sepsis in meta-analyses between fish oil-LE and S-LE; (2 studies; n = 40; very low-quality evidence).

AUTHORS' CONCLUSIONS

In the current review, we did not find any particular LE with or without fish oil to be better than another LE in preterm infants for prevention of PNALD/cholestasis, growth, mortality, ROP, BPD and other neonatal outcomes.In preterm infants with surgical conditions or cholestasis, there is currently insufficient evidence from randomised studies to determine with any certainty if fish oil LEs offer advantage in prevention or resolution of cholestasis or in any other clinical outcome.Further research, with larger well-designed trials, is warranted to evaluate the ideal composition of LE in preterm infants and the role of fish oil-containing and other LEs in the prevention and resolution of PNALD, ROP and other clinical outcomes.

Biological and Clinical Aspects of an Olive Oil-Based Lipid Emulsion-A Review

Intravenous lipid emulsions (ILEs) have been an integral component of parenteral nutrition for more than 50 years. Numerous formulations are available and are based on vegetable (soybean, olive, coconut) and animal (fish) oils. Therefore, each of these formulations has a unique fatty acid composition that offers both benefits and limitations. As clinical experience and our understanding of the effects of fatty acids on various physiological processes has grown, there is evidence to suggest that some ILEs may have benefits compared with others. Current evidence suggests that olive oil-based ILE may preserve immune, hepatobiliary, and endothelial cell function, and may reduce lipid peroxidation and plasma lipid levels. There is good evidence from a large randomized controlled study to support a benefit of olive oil-based ILE over soybean oil-based ILE on reducing infections in critically ill patients. At present there is limited evidence to demonstrate a benefit of olive oil-based ILE over other ILEs on glucose metabolism, and few data exist to demonstrate a benefit on clinical outcomes such as hospital or intensive care unit stay, duration of mechanical ventilation, or mortality. We review the current research and clinical evidence supporting the potential positive biological and clinical aspects of olive oil-based ILE and conclude that olive oil-based ILE is well tolerated and provides effective nutritional support to various PN-requiring patient populations. Olive oil-based ILE appears to support the innate immune system, is associated with fewer infections, induces less lipid peroxidation, and is not associated with increased hepatobiliary or lipid disturbances. These data would suggest that olive oil-based ILE is a valuable option in various PN-requiring patient populations.

Influence of different intravenous lipid emulsions on growth, development and laboratory and clinical outcomes in hospitalised paediatric patients: A systematic review

BACKGROUND & AIMS

Fats in the form of lipid emulsions (LEs) are an integral part of intravenous nutrition. The fatty acid composition of different LEs varies. The exact composition of a LE may influence cell and tissue function and clinical outcome. Currently, it is not clear which LE might be best for paediatric patients. We conducted a systematic review of the effects of different intravenous LEs in hospitalised paediatric patients.

METHODS

Randomised controlled trials published in a peer reviewed journal, written in the English language, and comparing two or more different intravenous LEs in hospitalised paediatric patients were included. Data on outcomes of relevance (growth, development, laboratory and clinical outcomes) were extracted, collated and interpreted.

RESULTS

Thirty-one articles involving 1522 infants or children were included. Most outcomes were not affected by the nature of the LE used. LEs containing fish oil, a source of omega-3 fatty acids, improved outcome of retinopathy of prematurity, decreased liver cholestasis and increased blood omega-3 fatty acid levels. LEs containing olive oil increased blood oleic acid level and had a cholesterol lowering effect.

CONCLUSION

Blood fatty acids are influenced by the nature of the intravenous LE used in hospitalised paediatric patients. Most studies suggest limited differences in relevant laboratory or clinical outcomes or in growth in paediatric patients receiving different LEs, although several studies do find benefits from including fish oil or olive oil. There is a need for larger trials to fully evaluate the effects of the available LE types in hospitalised paediatric patients.

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.

Fish oil- and soy oil-based lipid emulsions in neonatal parenteral nutrition: a systematic review and meta-analysis

BACKGROUND/OBJECTIVES

The precise role of fish oil-based lipid emulsions (FBL=any lipid emulsion containing any amount of fish oil) and soy oil-based lipid emulsions (SBL=any lipid emulsion not containing fish oil or containing at least 50% soy oil) in neonatal parenteral nutrition (PN) needs to be explored.

SUBJECTS/METHODS

The PubMed, MedLine and Google Scholar databases were searched for randomised control trials in which PN with FBL and SBL was the only difference between intervention and control groups. Methodological quality was assessed based on the Cochrane handbook for systemic reviews and Jadad's score. Revman 5.2 software was used for meta-analysis.

RESULTS

Of 420 trials, 25 met the inclusion criteria. The aggregate results showed that both FBLs and SBLs are beneficial. FBLs were associated with significantly lower incidences of cholestasis (relative risk (RR)=0.50; 95% confidence interval (CI)=0.27-0.92, P=0.03) compared with SBLs. FBLs also had a tendency to improve the rates of weight gain, increase in head circumference and the time to regain birth weight (mean difference (MD)=0.24; 95% CI=-0.63-0.15). SBLs were associated with reduced duration of respiratory support (MD=2.22, 95% CI=0.35-4.09, P=0.02) and mortality rate in the first 28 days (RR=1.24, 95% CI=-0.72-2.13).

CONCLUSIONS

Both FBLs and SBLs are beneficial for neonatal PN. FBLs reduce cholestasis, and SBLs reduce the duration of respiratory support.

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.

Comparison of Formulas Based on Lipid Emulsions of Olive Oil, Soybean Oil, or Several Oils for Parenteral Nutrition: A Systematic Review and Meta-Analysis

Many studies have reported that olive oil-based lipid emulsion (LE) formulas of soybean oil, medium-chain triglycerides, olive oil, and fish oil (SMOF) may be a viable alternative for parenteral nutrition. However, some randomized controlled clinical trials (RCTs) have raised concerns regarding the nutritional benefits and safety of SMOFs. We searched principally the MEDLINE, Cumulative Index to Nursing and Allied Health Literature, Scopus, EMBASE, and Cochrane Central Register of Controlled Trials databases from inception to March 2014 for the relevant literature and conducted a meta-analysis of 15 selected RCTs that 1) compared either olive oil- or SMOF-based LEs with soybean oil-based LEs and 2) reported plasma concentrations of α-tocopherol, oleic acid, and ω-6 (n-6) and ω-3 (n-3) long-chain polyunsaturated fatty acids (PUFAs) and liver concentrations of total bilirubin and the enzymes alanine transaminase, aspartate transaminase, alkaline phosphatase, and γ-glutamyl transferase. The meta-analysis suggested that SMOF-based LEs were associated with higher plasma concentrations of plasma α-tocopherol, oleic acid, and the ω-3 PUFAs eicosapentaenoic and docosahexaenoic acid. Olive oil- and SMOF-based LEs correlated with lower plasma concentrations of long-chain ω-6 PUFAs and were similar to soybean oil-based LEs with regard to their effects on liver function indicators. In summary, olive oil- and SMOF-based LEs have nutritional advantages over soybean oil-based LEs and are similarly safe. However, their performance in clinical settings requires further investigation.

Alternative lipid emulsions versus pure soy oil based lipid emulsions for parenterally fed preterm infants

BACKGROUND

The pure soybean oil based lipid emulsions (S-LE) conventionally used for parenteral nutrition (PN) in preterm infants have high polyunsaturated fatty acid (PUFA) content. The newer lipid emulsions (LE) from alternative lipid sources with reduced PUFA content may improve clinical outcomes in preterm infants.

OBJECTIVES

To determine the safety and efficacy of the newer alternative LE compared with the conventional S-LE for PN in preterm infants.

SEARCH METHODS

We used the standard search strategy of the Cochrane Neonatal Review Group (CNRG) to search the Cochrane Central Register of Controlled Trials (CENTRAL; Issue 7), MEDLINE (1946 to 31 July 2015), EMBASE (1947 to 31 July 2015), CINAHL (1982 to 31 July 2015), Web of Science (31 July 2015), conference proceedings, trial registries (clinicaltrials.gov, controlled-trials.com, WHO's ICTRP), and the reference lists of retrieved articles for randomised controlled trials and quasi-randomised trials.

SELECTION CRITERIA

Randomised or quasi-randomised controlled trials in preterm infants (< 37 weeks), comparing newer alternative LE with S-LE.

DATA COLLECTION AND ANALYSIS

Data collection and analysis conformed to the methods of the CNRG. We assessed the quality of evidence for important outcomes using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach, in addition to reporting the conventional statistical significance of results.

MAIN RESULTS

Fifteen studies (N = 979 infants) are included in this review. Alternative LE including medium chain triglycerides/long chain triglycerides (MCT/LCT) LE (3 studies; n = 108), MCT-olive-fish-soy oil-LE (MOFS-LE; 7 studies; n = 469), MCT-fish-soy oil-LE (MFS-LE; 1 study; n = 60), olive-soy oil-LE (OS-LE; 7 studies; n = 406), and borage-soy oil-LE (BS-LE; 1 study; n = 34) were compared with S-LE. The different LE were also considered together to compare 'all fish oil containing-LE' versus S-LE (7 studies; n = 499) and 'all alternative LE' versus S-LE (15 studies; n = 979). Some studies had multiple intervention arms and were included in more than one comparison. No study compared pure fish oil-LE or structured-LE to S-LE.The GRADE quality of evidence (GRADE QoE) ranged from 'low' to 'very low.' Evidence came mostly from small single centre studies, many focusing on biochemical aspects as their primary outcomes, with optimal information size not achieved for the important clinical outcomes in any comparison.In the primary outcomes of the review there was a pooled effect towards decreased bronchopulmonary dysplasia (BPD) in OS-LE vs S-LE (4 studies, n = 261) not reaching statistical significance (typical risk ratio (RR) 0.69, 95% confidence interval (CI) 0.46 to 1.04, I² = 32%; typical risk difference (RD) -0.08, 95% CI -0.17 to 0.00, I² = 76%; GRADE QoE: 'very low'). No difference in BPD was observed in any other comparison. There were no statistically significant differences in the primary outcomes of death, growth rate (g/kg/day) or days to regain birth weight in any comparison.Retinopathy of prematurity (ROP) stage 1-2 was reported to be statistically significantly lower in one single centre study (n = 80) in the MOFS-LE group compared with the S-LE group (1/40 vs 12/40, respectively; RR 0.08, 95% CI 0.01 to 0.61; RD -0.27, 95% CI -0.43 to -0.12; number needed to benefit (NNTB) 4, 95% CI 2 to 8). However there were no statistically significant differences in the secondary outcome of ROP ≥ stage 3 in any of the individual studies or in any comparison (GRADE QoE: 'low' to 'very low'). No other study reported on ROP stages 1 and 2 separately.There were no statistically significant differences in the secondary outcomes of sepsis, PN associated liver disease (PNALD)/cholestasis, ventilation duration, necrotising enterocolitis (NEC) ≥ stage 2, jaundice requiring treatment, intraventricular haemorrhage grade III-IV, periventricular leukomalacia (PVL), patent ductus arteriosus (PDA), hypertriglyceridaemia, and hyperglycaemia in any comparison.No study reported on neurodevelopmental outcomes or essential fatty acid deficiency.

AUTHORS' CONCLUSIONS

All lipid emulsions in this review appeared to be safe and were well tolerated in preterm infants. Compared with the pure soy oil based LE, use of MOFS-LE was associated with a decrease in the early stages (1-2) of ROP in one study. However there were no statistically significant differences in clinically important outcomes including death, growth, BPD, sepsis, ROP ≥ stage 3, and PNALD with the use of newer alternative LE versus the conventional pure soy oil based LE (GRADE QoE ranged from 'low' to 'very low'). Currently there is insufficient evidence to recommend any alternative LE over S-LE or vice versa in preterm infants.Larger randomised studies focusing on important clinical outcomes, targeting specific 'at risk' population subgroups (e.g. extreme prematurity, long term PN, etc), and exploring the effect of different proportions of lipid constituents are required to evaluate the effectiveness of newer lipid emulsions compared with the conventional pure soy based LE in preterm infants.

Impact of parenteral fat composition on cholestasis in preterm infants

OBJECTIVES

Parenteral nutrition-associated liver disease (PNALD) is frequently detected in neonatal intensive care units. Parenteral lipid emulsion (PLE) content has been implicated in its pathogenesis. We aimed to study the effect on incidence and outcome of PNALD by replacing soy-based PLE with olive oil-based PLE in a population-based group of preterm infants.

METHODS

All infants in Stockholm County with gestational age (GA) <30 weeks were included (n = 615). Infants who died before 28 days of age or were referred to or from other regions were excluded (n = 97). PNALD was defined as conjugated serum bilirubin ≥ 30 μmol/L and exceeding 20% of the total fraction on at least 2 occasions. Two different 2-year time periods were compared: before (SOY period) and after (OLIVE period) switching PLE. For each PNALD case, 2 GA-matched controls were randomly identified.

RESULTS

PNALD incidence was 14.8% (37/250) in the SOY period and 12.7% (34/268) in the OLIVE period (P = 0.52). The OLIVE infants with PNALD had more risk factors, such as lower GA and longer periods of parenteral nutrition, for developing PNALD than the SOY infants. Nevertheless, treatment during the SOY period was an independent risk factor for PNALD in logistic regression analysis.

CONCLUSIONS

Population-based incidence of PNALD is 1 of 7 in preterm infants with GA < 30 weeks. Changing from soy oil to olive oil-based PLE did not decrease the incidence of PNALD significantly. Olive oil-based PLE carries an equal or slightly decreased risk to develop PNALD compared with soy oil-based PLE.

Special Issue on "Analytical Methods for Oxidized Biomolecules and Antioxidants" The use of isoprostanoids as biomarkers of oxidative damage, and their role in human dietary intervention studies

Isoprostanoids are a group of non-enzymatic oxidized lipids from polyunsaturated fatty acids. They are commonly used as biomarkers for oxidative damage, to assess in vivo lipid peroxidation in diseases related to the vascular system and neurodegeneration. Currently, there is a mismatch with the outcome in the use of these biomarkers in intervention studies, particularly when testing the effect of antioxidants such as vitamins C and E, or zinc, or a cocktail of these, with other food components. Much of this is because the biomarkers, the method of measurement, and the duration of supplementation are unsuitable. In this review, we will highlight the formation of isoprostanoids from their respective fatty acids, and their application as biomarkers for oxidative damage in vivo, considering human dietary intervention studies evaluating plasma and urine, using mass spectrometry techniques.

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.

Balancing the risks and benefits of parenteral nutrition for preterm infants: can we define the optimal composition?

Nutrient intakes in preterm infants are frequently inadequate and are associated with worse neuro-developmental outcome. Preterm infants take time to establish enteral intakes, and parenteral nutrition (PN) is now an integral component of care. Despite this, the evidence base for PN intakes is extremely limited. There remains uncertainty over safe initial and maximum amounts of macronutrients, and the optimal amino acid and lipid composition. Studies have tended to focus on short-term growth measures and there are few studies with long-term follow-up. There may be a tradeoff between improving cognitive outcomes while minimising metabolic harm that means determining the optimal regimen will require long-term follow-up. Given the importance of appropriate nutrition for long-term metabolic and cognitive health, and the associated healthcare costs, optimising the composition of PN deserves to be seen as a research priority in neonatal medicine.

Standardised neonatal parenteral nutrition formulations - an Australasian group consensus 2012

Standardised parenteral nutrition formulations are routinely used in the neonatal intensive care units in Australia and New Zealand. In 2010, a multidisciplinary group was formed to achieve a consensus on the formulations acceptable to majority of the neonatal intensive care units. Literature review was undertaken for each nutrient and recommendations were developed in a series of meetings held between November 2010 and April 2011. Three standard and 2 optional amino acid/dextrose formulations and one lipid emulsion were agreed by majority participants in the consensus. This has a potential to standardise neonatal parenteral nutrition guidelines, reduce costs and prescription errors.

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.

Standardised parenteral nutrition

Parenteral nutrition (PN) has become an integral part of clinical management of very low birth weight premature neonates. Traditionally different components of PN are prescribed individually considering requirements of an individual neonate (IPN). More recently, standardised PN formulations (SPN) for preterm neonates have been assessed and may have advantages including better provision of nutrients, less prescription and administration errors, decreased risk of infection, and cost savings. The recent introduction of triple-chamber bag that provides total nutrient admixture for neonates may have additional advantage of decreased risk of contamination and ease of administration.

Parenteral lipid administration to very-low-birth-weight infants--early introduction of lipids and use of new lipid emulsions: a systematic review and meta-analysis

BACKGROUND

The use of intravenous lipid emulsions in preterm infants has been limited by concerns regarding impaired lipid tolerance. As a result, the time of initiation of parenteral lipid infusion to very-low-birth-weight (VLBW) infants varies widely among different neonatal intensive care units. However, lipids provide energy for protein synthesis and supply essential fatty acids that are necessary for central nervous system development.

OBJECTIVE

The objective was to summarize the effects of initiation of lipids within the first 2 d of life and the effects of different lipid compositions on growth and morbidities in VLBW infants.

DESIGN

A systematic review and meta-analysis of publications identified in a search of PubMed, EMBASE, and Cochrane databases was undertaken. Randomized controlled studies were eligible if information on growth was available.

RESULTS

The search yielded 14 studies. No differences were observed in growth or morbidity with early lipid initiation. We found a weak favorable association of non-purely soybean-based emulsions with the incidence of sepsis (RR: 0.75; 95% CI: 0.56, 1.00).

CONCLUSIONS

The initiation of lipids within the first 2 d of life in VLBW infants appears to be safe and well tolerated; however, beneficial effects on growth could not be shown for this treatment nor for the type of lipid emulsion. Emulsions that are not purely soybean oil-based might be associated with a lower incidence of sepsis. Large-scale randomized controlled trials in preterm infants are warranted to determine whether early initiation of lipids and lipid emulsions that are not purely soybean oil-based results in improved long-term outcomes.

The metabolic effects of two different lipid emulsions used in parenterally fed premature infants--a randomized comparative study

OBJECTIVE

To compare the effects of two different lipid emulsions, based on soybean oil and olive oil respectively on plasma lipid concentrations and acylcarnitine profile of very low birth weight infants.

DESIGN

Randomized comparative study.

PATIENTS AND METHODS

Forty very low birth weight infants, ≤32 weeks of gestational age and receiving at least 40% of the calorie taken by parenteral nutrition from lipid solution at 14th day of life were evaluated. Group I (n=20) received soybean oil based lipid emulsion (Intralipid®) and Group II (n=20) received olive oil based lipid emulsion (Clinoleic®).

MAIN OUTCOME MEASURES

Plasma lipid concentrations and acylcarnitine profile were assessed.

RESULTS

Triglyceride, cholesterol, high and low density lipoprotein levels, liver function tests were similar between two groups whereas very low density lipoprotein level was statistically lower in Group I (p<0.05). Free carnitine levels were 15.73±10.67 in Group I and 34.25±22.18 μM in Group II (p=0.012) and hexanoyl carnitine levels 2.18±2.10 in Group I and 0.38±0.12 μM in Group II, respectively (p=0.005). Plasma medium chain acylcarnitine levels were significantly higher in Group I.

CONCLUSIONS

Low levels of very low density lipoprotein in Group I may be a way of hemostasis to keep the serum triglyceride within normal levels. Lower free carnitine levels in soybean oil-based group is the result of carnitine need during the mitochondrial transport of long chain fatty acids. In Group I, due to the inefficient transport of medium chain fatty acids into the mitochondria, medium chain acylcarnitines accumulate in plasma. This may be the reason of lower carnitine levels in Group I. We suggest that higher levels of hexanoyl carnitine, reflecting defective mitochondrial transport of hexanoyl which leads immunsupression, may be the cause of higher sepsis risk in Group I.

Improved outcome in neonatal short bowel syndrome using parenteral fish oil in combination with ω-6/9 lipid emulsions

BACKGROUND

Newborn infants with short bowel syndrome (SBS) represent a high-risk group of developing intestinal failure-associated liver disease (IFALD), which may be fatal. However, infants have a great capacity for intestinal growth and adaptation if IFALD can be prevented or reversed. A major contributing factor to IFALD may be the soybean oil-based intravenous lipid emulsions used since the introduction of parenteral nutrition (PN) 40 years ago.

METHODS

This retrospective study compares the outcome in 20 neonates with SBS treated with parenteral fish oil (Omegaven) in combination with ω-6/9 lipid emulsions (ClinOleic) with the outcome in a historical cohort of 18 patients with SBS who received a soybean oil-based intravenous lipid emulsion (Intralipid).

RESULTS

Median gestational age was 26 weeks in the treatment group and 35.5 weeks in the historical group. All patients were started on PN containing Intralipid that was switched to ClinOleic/Omegaven in the treatment group at a median age of 39 gestational weeks. In the treatment group, direct bilirubin levels were reversed in all 14 survivors with cholestasis (direct bilirubin >50 umol/L). Median time to reversal was 2.9 months. Only 2 patients died of liver failure (10%). In the historical cohort, 6 patients (33%) died of liver failure, and only 2 patients showed normalization of bilirubin levels.

CONCLUSIONS

Parenteral fish oil in combination with ω-6/9 lipid emulsions was associated with improved outcome in premature neonates with SBS. When used instead of traditional soybean-based emulsions, this mixed lipid emulsion may facilitate intestinal adaptation by increasing the IFALD-free period.

Parenteral nutrition-associated cholestasis: an American Pediatric Surgical Association Outcomes and Clinical Trials Committee systematic review

OBJECTIVE

The aim of this study was to review evidence-based data addressing key clinical questions regarding parenteral nutrition-associated cholestasis (PNAC) and parenteral nutrition-associated liver disease (PNALD) in children.

DATA SOURCE

Data were obtained from PubMed, Medicine databases of the English literature (up to October 2010), and the Cochrane Database of Systematic Reviews.

STUDY SELECTION

The review of PNAC/PNALD has been divided into 4 areas to simplify one's understanding of the current knowledge regarding the pathogenesis and treatment of this disease: (1) nonnutrient risk factors associated with PNAC, (2) PNAC and lipid emulsions, (3) nutritional (nonlipid) considerations in the prevention of PNAC, and (4) supplemental medications in the prevention and treatment of PNAC.

RESULTS

The data for each topic area relevant to the clinical practice of pediatric surgery were reviewed, evaluated, graded, and summarized.

CONCLUSIONS

Although the conditions of PNAC and PNALD have been well recognized for more than 30 years, only a few concrete associations and treatment protocols have been established.

Short-term use of parenteral nutrition with a lipid emulsion containing a mixture of soybean oil, olive oil, medium-chain triglycerides, and fish oil: a randomized double-blind study in preterm infants

BACKGROUND

For premature neonates needing parenteral nutrition (PN), a balanced lipid supply is crucial. The authors hypothesized that a lipid emulsion containing medium-chain triglycerides (MCTs) and soybean, olive, and fish oils would be as safe and well tolerated as a soybean emulsion while beneficially influencing the fatty acid profile.

METHODS

Double-blind, controlled study in 53 neonates (<34 weeks' gestation) randomized to receive at least 7 days of PN containing either an emulsion of MCTs and soybean, olive, and fish oils or a soybean oil emulsion. Target lipid dosage was 1.0 g fat/kg body weight [BW]/d on days 1-3, 2 g/kg BW/d on day 4, 3 g/kg BW/d on day 5, and 3.5 g/kg BW/d on days 6-14.

RESULTS

Test emulsion vs control, mean ± SD: baseline triglyceride concentrations were 0.52 ± 0.16 vs 0.54 ± 0.19 mmol/L and increased similarly in both groups to 0.69 ± 0.38 vs 0.67 ± 0.36 on day 8 of treatment (P = .781 for change). A significantly higher decrease in total and direct bilirubin vs baseline was seen in the test group compared with the control group P < .05 between groups). In plasma and red blood cell phospholipids, eicosapentaenoic acid and docosahexaenoic acid were higher, and the n-6/n-3 fatty acid ratio was lower in the test group (P < .05 vs control).

CONCLUSIONS

The lipid emulsion, based on a mixture of MCTs and soybean, olive, and fish oils, was safe and well tolerated by preterm infants while beneficially modulating the fatty acid profile.

Lipid peroxidation in all-in-one admixtures for preterm neonates: impact of amount of lipid, type of lipid emulsion and delivery condition

AIM

To evaluate the effect of lipid emulsion composition and delivery condition on lipid peroxidation in typical all-in-one parenteral admixtures for preterm neonates.

METHODS

Malonedialdehyde (MDA) concentrations were assessed in different all-in-one admixtures. We evaluated the effects of fat blend (three lipid emulsions) and the amount of lipids, as well as the effects of protecting bags and/or tubing from ambient light and storage for 72 h. MDA was measured by liquid chromatography/mass spectrometry.

RESULTS

Three hundred and sixty samples were collected from 114 admixtures. Neither the type of lipid (p = 0.43) nor the interaction between light and type of lipid (p = 0.49) had any influence on final MDA concentrations, but the increase in MDA concentration at 24 h (T(24)) was related to light exposure (p < 0.001). The increase in MDA concentration was related to the increase in lipid amount in the admixture at T(0) (r = 0.77) and T(24) (r = 0.86). MDA concentrations in solutions stored for 72 h showed no significant increase, with no difference between the three lipid emulsions (p = 0.69).

CONCLUSION

All-in-one admixtures may be interesting for the parenteral nutrition of preterm neonates. Protection from light and restricting the amount of lipid to what is required for appropriate energy provision are essential to limit lipid peroxidation.

Comparison of lipid emulsions on antioxidant capacity in preterm infants receiving parenteral nutrition

BACKGROUND

Although a variety of different lipid emulsions with varying fatty acid contents have been developed, there are some concerns about the administration of these lipid emulsions because of potential adverse effects, including oxidative stress-related morbidity. The aim of the present study was to evaluate and compare the effects of the standard soybean oil-based and olive oil-based i.v. lipid emulsions (ILE) on oxidative stress, determined by total antioxidant capacity (TAC), and to investigate the safety of the use of these two emulsions in terms of biochemical indices.

METHODS

In this prospective study, premature infants were randomly assigned to two groups, each group consisting of 32 patients who received parenteral ILE of either 20% olive oil or 20% soybean oil. They were given ILE for 7 days and then were evaluated with regard to TAC.

RESULTS

No statistically significant difference was observed between the groups in terms of routine biochemical parameters. TAC for both groups on day 7 was significantly lower compared with that on day 0. Although the decrease in TAC within 7 days of ILE administration was greater in the soybean group compared with that in the olive oil group, it was not statistically significant.

CONCLUSIONS

Olive oil-based ILE exhibit similar antioxidant activity and can be used as an alternative to soybean oil-based ILE. TAC significantly decreased in infants following administration of either lipid emulsion, and premature infants tolerated either ILE well, both biochemically and clinically.

Prevention and reversal of intestinal failure-associated liver disease in premature infants with short bowel syndrome using intravenous fish oil in combination with omega-6/9 lipid emulsions

Although premature infants with short bowel syndrome are at the highest risk of developing intestinal failure-associated liver disease (IFALD), they have great capacity for intestinal growth and adaptation if IFALD can be prevented. Conventional soybean oil-based intravenous lipid emulsions have been associated with IFALD. This study presents data on 5 premature neonates with short bowel syndrome treated with a combination of parenteral fish oil- and olive/soybean-based lipid emulsion for periods ranging between 7 and 17 months. Despite an enteral tolerance of less than 50% in 4 of these patients during their first year of life, direct bilirubin levels normalized while on this combination of ClinOleic (Baxter, Maurepas, France)/Omegaven (Fresenius Kabi, Bad Homburg, Germany) at a 1:1 ratio. None of our patients developed irreversible IFALD even though all of them were premature, had undergone multiple major surgical procedures, and had experienced several episodes of sepsis. Thus far, we have not seen any adverse effects of this mixed lipid emulsion in these preterm infants. All 5 patients are growing and developing well and have normal liver function.

Lipids for parenteral nutrition in neonates

PURPOSE OF REVIEW

In neonatal intensive care units, the interest and scope for research in the field of intravenous lipids has significantly widened in recent years. This brief review covers the advances in this field in the last 2 years.

RECENT FINDINGS

These include a significant amount of research in evaluating safety and efficacy of novel lipid emulsions that include olive oil or fish oil. Short-term studies involving novel lipid emulsions have documented safety and benefits in terms of reduced inflammation and lipid peroxidation. Fish oil-based lipid emulsions have also been used to prevent and treat parenteral nutrition-induced cholestasis. Other areas of progress include stability studies of all-in-one parenteral nutrition mixtures including lipid emulsions for neonates.

SUMMARY

Since the first soybean oil-based lipid emulsions were introduced 50 years ago, progress has been made in understanding the composition, dose and clinical effects of parenteral lipids in neonatal patients. However there is a paucity of data in terms of definitive head-to-head trials of different novel lipid emulsions evaluating short-term as well as long-term clinically important outcomes including neurodevelopment. Future research is required to determine long-term benefits of novel lipid emulsions for neurological outcome and effects on the immune system.