Pharmaceutical and clinical aspects of parenteral lipid emulsions in neonatology

Morbidity Outcomes of Very Low Birth Weight Neonates Receiving Parenteral Nutrition with Fish Oil Enriched Lipid Emulsion or Lipid Emulsion with Soybean Oil: An Observational Study

Intralipid (Fresenius Kabi) was the most commonly used lipid emulsion in parenteral nutrition (PN), with a 100% soybean oil composition, a low vitamin E content, and a ω-6: ω-3 ratio of 7:1. A recent alternative formulation is SMOFlipid (Fresenius Kabi), with a ω-6: ω-3 ratio of 5:2 and higher vitamin E content. A retrospective observational study was conducted to determine neonatal morbidity in very low birth weight (VLBW) premature infants during two periods: P1, when PN was based exclusively on Intralipid, and P2, when only SMOFlipid was supplied. In total, 170 VLBW neonates were analyzed, of whom 103 received PN for more than 6 days, 56 during P1, and 47 during P2. In both periods, the antenatal and neonatal characteristics of the cohort were comparable. In this analysis, the prevalence of associated comorbidities was determined. During P2, there were fewer cases of moderate to severe bronchopulmonary dysplasia (BPD) and of cholestasis, but more cases of late sepsis, mainly Staphylococcus epidermidis. No changes in the prevalence of other neonatal comorbidities were observed. We believe that the SMOFlipid used in PN could discreetly improve the prevalence of cholestasis or BPD.

Growth of Head Circumference and Body Length in Preterm Infants Receiving a Multicomponent vs a Soybean-Based Lipid Emulsion: A Randomized Controlled Trial

BACKGROUND

The growth of very low-birth-weight (VLBW) infants relies, to a large extent, on parenteral nutrition (PN) during the early weeks of life. Despite the parenteral nutrients supply, extrauterine growth restriction remains the main concern for these infants. A parenteral multicomponent lipid emulsion (MLE) might improve growth and neurological outcomes, delivering fats for brain growth that the traditional soybean-based lipid emulsion (SLE) fails to provide. We hypothesize that the use of an MLE in PN may reduce the loss of head circumference (HC) z-score from birth to 36 weeks' postmenstrual age (PMA) or at discharge compared with the use of an SLE in VLBW infants.

METHODS

Infants with BW ≤1250 g, without malformations or chromosomal abnormalities, were randomly assigned to receive an MLE or an SLE. The primary outcome was the change in HC z-score (HC Δ z-score) from birth to 36 weeks' PMA or at discharge. Secondary outcomes included the change in weight and length z-score (W Δ z-score and L Δ z-score) as well as incidence of late-onset sepsis and PN-associated cholestasis (PNAC).

RESULTS

Of the 128 infants randomized, 51 infants in the MLE group and 50 infants in the SLE group were analyzed. The MLE was significantly associated with a decreased loss in HC and length z-scores from birth to 36 weeks' PMA or at discharge.

CONCLUSIONS

This is the first randomized controlled trial providing the evidence that an MLE is associated with improved HC growth in comparison with a pure SLE.

Multi-component lipid emulsion vs soy-based lipid emulsion for very low birth weight preterm neonates: A pre-post comparative study

OBJECTIVE

To examine the effectiveness of soybean oil-medium chain triglycerides-olive oil-fish oil lipid emulsion (SMOF-LE) on clinical outcomes of very-low-birth-weight neonates.

STUDY DESIGN

We conducted a pre-post comparative study of very-low-birth-weight neonates, dividing them according to lipid emulsion received: Intralipid (soy-based; n = 680) or SMOF-LE (n = 617). Primary outcomes were mortality, chronic lung disease, severe retinopathy, infection, and necrotising enterocolitis. Secondary outcomes were cholestasis, osteopenia, time to full feeds, and time to regain birthweight.

RESULTS

Baseline characteristics between groups were comparable. Primary outcomes did not differ significantly between groups, although any retinopathy was significantly lower in the SMOF-LE group. SMOF-LE group had lower odds of cholestasis, osteopenia, and lipid interruption, and reduced times to full feeds and to regain birthweight.

CONCLUSIONS

Compared with Intralipid, SMOF-LE was not associated with differences in mortality and major morbidities but was associated with lower odds of any retinopathy, cholestasis, and osteopenia; and improved lipid tolerance.

Lipid emulsions for parenterally fed term and late preterm infants

BACKGROUND

Lipid emulsions (LE) form a vital component of infant nutrition for critically ill, late preterm or term infants, particularly for those with gastrointestinal failure. Conventionally used soybean oil-based LE (S-LE) have high polyunsaturated fatty acid (PUFA) content and phytosterols, which may contribute to adverse effects including parenteral nutrition-associated liver disease (PNALD).

OBJECTIVES

To compare the safety and efficacy of all LE for parenteral nutrition (PN) in term and late preterm infants (between 34 weeks' gestation and 36 weeks' and six days' gestation) with or without surgical conditions or PNALD within first six months of life, using all possible direct comparisons.

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 June 2018), CINAHL (1982 to 18 June 2018), MIDRIS (1971 to 31 May 2018), conference proceedings, trial registries (ClinicalTrials.gov and the WHO's Trials Registry), and the reference lists of retrieved articles for randomised controlled trials and quasi-randomised trials.

SELECTION CRITERIA

Randomised or quasi-randomised controlled studies in term and late preterm infants, with or without surgical conditions or PNALD.

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 the conventional statistical significance of results.

MAIN RESULTS

The review included nine randomised studies (n = 273). LE were classified in three broad groups: 1. all fish oil-containing LE including pure fish oil (F-LE) and multisource LE (e.g. medium-chain triglycerides (MCT)-olive-fish-soybean oil-LE (MOFS-LE), MCT-fish-soy oil-LE (MFS-LE) and olive-fish-soy-LE (OFS-LE)); 2. conventional pure S-LE; 3. alternative-LE (e.g. MCT-soy-LE (MS-LE), olive-soy-LE (OS-LE) and borage oil-based LE).We considered four broad comparisons: 1. all fish oil LE versus non-fish oil LE (6 studies; n = 182); 2. fish oil LE versus another fish oil LE (0 studies); 3. alternative-LE versus S-LE (3 studies; n = 91); 4. alternative-LE versus another alternative-LE (0 studies) in term and late preterm infants (0 studies), term and late preterm infants with surgical conditions (7 studies; n = 233) and term and late preterm infants with PNALD/cholestasis (2 studies; n = 40).PNALD/cholestasis was defined as conjugated bilirubin (Cbil) 2 mg/dL or greater and resolution of PNALD/cholestasis as Cbil less than 2 mg/dL. We put no restriction on timing of PNALD detection. There was heterogeneity in definitions and time points for detecting PNALD in the included studies.We found one study each in surgical infants and in infants with cholestasis, showing no evidence of difference in incidence or resolution of PNALD/cholestasis (Cbil cut-off: 2 mg/dL) with use of fish oil-containing LE compared to S-LE.We considered an outcome allowing for any definition of PNALD (different Cbil cut-off levels). In infants with surgical conditions and no pre-existing PNALD, meta-analysis showed no difference in the incidence of PNALD/cholestasis (any definition) with use of fish oil-containing LE compared to S-LE (typical risk ratio (RR) 1.20, 95% confidence interval (CI) 0.38 to 3.76; typical risk difference (RD) 0.03, 95% CI -0.14 to 0.20; 2 studies; n = 68; low-quality evidence). In infants with PNALD/cholestasis (any definition), use of fish oil-LEs was associated with significantly less cholestasis compared to the S-LE group (typical risk ratio (RR) 0.54, 95% confidence interval (CI) 0.32 to 0.91; typical risk difference (RD) -0.39, 95% CI -0.65 to -0.12; number needed to treat for additional beneficial outcome (NNTB) 3, 95% CI 2 to 9; 2 studies; n = 40; very low-quality evidence). This outcome had very low number of participants from two small studies with differences in study methodology and early termination in one study, which increased uncertainty about the effect estimates.One study in infants with cholestasis reported significantly better weight gain with a pure fish oil LE compared to a 10% S-LE (45 g/week, 95% CI 15.0 to 75.0; n = 16; very low-quality evidence). There were no significant differences in growth parameters in studies with surgical populations.For the secondary outcomes, in infants with cholestasis, one study (n = 24) reported significantly lower conjugated bilirubin levels but higher gamma glutamyl transferase levels with MOFS-LE (SMOFlipid) versus S-LE (Intralipid) and another study (n = 16), which was terminated early, reported significantly higher rates of rise in alanine aminotransferase (ALT) and conjugated bilirubin levels in the S-LE group compared to pure F-LE (Omegaven).In surgical infants, two studies each reported on hypertriglyceridaemia and Cbil levels with one study in each outcome showing significant benefit with use of a F-LE and the other study showing no difference between the groups. Meta-analysis was not performed for either of these outcomes as there were only two studies showing conflicting results with high heterogeneity between the studies.There was no evidence of differences in death, sepsis, alkaline phosphatase and ALT levels in infants with surgical conditions or cholestasis (very low-quality evidence).One study reported neurodevelopmental outcomes at six and 24 months in infants with surgical conditions (n = 11) with no evidence of difference with use of pure F-LE versus S-LE. Another study in infants with cholestasis (n = 16) reported no difference in head growth velocity between pure F-LE versus S-LE.GRADE quality of evidence ranged from low to very low as the included studies were small single-centre studies. Three of the six studies that contributed data to the review were terminated early for various reasons.

AUTHORS' CONCLUSIONS

Based on the current review, there is insufficient data from randomised studies to determine with any certainty, the potential benefit of any LE including fish oil-containing LEs over another LE, for prevention or resolution of PNALD/cholestasis or any other outcomes in term and late preterm infants with underlying surgical conditions or cholestasis. There were no studies in infants without surgical conditions or cholestasis.Further research is required to establish role of fish oil or lipids from other sources in LEs to improve PNALD/cholestasis, and other clinical outcomes in parenterally fed term and late preterm infants.

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.

A HPLC method to monitor the occurrence of lipid peroxidation in intravenous lipid emulsions used in parenteral nutrition using in-line UV and charged aerosol detection

Parenteral Nutrition (PN) provides life sustaining support where gastrointestinal nutrition is inadequate due to disease or prematurity. Intravenous lipid emulsions (IVLEs) form a staple part of PN. Whilst the physical stability of IVLE's is relatively well known and quantified, chemical stability is an area where little testing has occurred. We report a new sensitive method for the monitoring of selected triglycerides present within two IVLEs and the detection and quantification of the peroxidation product 4-hydroxynonenal (HNE) using HPLC with in-line UV and charged aerosol detection (CAD). IVLEs used included the soy-bean oil based emulsion Intralipid^® 20% and SMOFlipid^® 20% (Fresenius Kabi UK), based on soy-bean, olive, fish oil and medium chain triglycerides. Assay validation gave R² values of ≥0.99 for all selected triglyceride peaks and 4-hydroxynonenal. Inter and intra-day repeatability gave RSD values < 7.2% for CAD detection, achieving a precise and repeatable method. HNE was confirmed through internal standardisation of the HPLC method. Selected triglycerides were identified using ESI-MS with MicroTOF. This novel method permits the chemical stability of IVLEs to be quantified and monitored in respect to lipid peroxidation during storage prior to delivery to the patient, ensuring the optimal safety of IVLEs in a clinical setting.

Lipid emulsions for parenterally fed preterm infants

This is a protocol for a Cochrane Review (Intervention). The objectives are as follows:

The primary objective is to compare the effectiveness and safety of lipid formulations from different sources, including soybean oil‐based, multicomponent, olive oil‐based, and fish oil–based, in parenterally fed preterm infants.

The secondary objective is to determine the effectiveness and safety of alternative lipid emulsions compared with soybean oil‐based lipid emulsions in relation to gestational age (less than 30 weeks' gestation; 30 weeks' gestation or more), birth weight (1000 grams or less; more than 1000 grams), clinical condition (surgical patients, patients with established cholestasis).

Influence of Human Milk and Parenteral Lipid Emulsions on Serum Fatty Acid Profiles in Extremely Preterm Infants

Background

Infants born prematurely are at risk of a deficiency in ω‐6 and ω‐3 long‐chain polyunsaturated fatty acids (LC‐PUFAs) arachidonic acid (AA) and docosahexaenoic acid (DHA). We investigated how fatty acids from breast milk and parenteral lipid emulsions shape serum LC‐PUFA profiles in extremely preterm infants during early perinatal life.

Methods

Ninety infants born < 28 weeks gestational age were randomized to receive parenteral lipids with or without the ω‐3 LC‐PUFAs eicosapentaenoic acid (EPA) and DHA (SMOFlipid: Fresenius Kabi, Uppsala, Sweden, or Clinoleic: Baxter Medical AB, Kista, Sweden, respectively). The fatty acid composition of infant serum phospholipids was determined from birth to postmenstrual age 40 weeks, and in mother's milk total lipids on postnatal day 7. Enteral and parenteral intake of LC‐PUFAs was correlated with levels in infant serum.

Results

Infants administered parenteral ω‐3 LC‐PUFAs received 4.4 and 19.3 times more DHA and EPA, respectively, over the first 2 weeks of life. Parenteral EPA but not DHA correlated with levels in infant serum. We found linear relationships between dietary EPA and DHA and infant serum levels in the Clinoleic (Baxter Medical AB) group. The volume of administered SMOFlipid (Fresenius Kabi) was inversely correlated with serum AA, whereas Clinoleic (Baxter Medical AB) inversely correlated with serum EPA and DHA.

Conclusions

There appears to be no or low correlation between the amount of DHA administered parenterally and levels measured in serum. Whether this observation reflects serum phospholipid fraction only or truly represents the amount of accreted DHA needs to be investigated. None of the parenteral lipid emulsions satisfactorily maintained high levels of both ω‐6 and ω‐3 LC‐PUFAs in infant serum.

Lipid peroxidation: Its effects on the formulation and use of pharmaceutical emulsions

Pharmaceutical delivery systems are developed to improve the physicochemical properties of therapeutic compounds. Emulsions are one of these drug delivering systems formulated using water, oils and lipids as main ingredients. Extensive data are usually generated on the physical and chemical characteristics of these oil-in-water and lipid emulsions. However, the oxidative tendency of emulsions is often overlooked. Oxidation impacts the overall quality and safety of these pharmaceutical emulsions. Additionally, introducing oxidatively unstable emulsions into biological systems further promotes oxidation in situ. Products of these reactions then continue to pose serious harm to cells and fuel other physiological oxidation reactions. Consequently, the increase of oxidation products leads to oxidative damage to biological systems. Thus, emulsions with lower lipid peroxidation are more stable and will reduce the negative effects of oxidation in situ. Preventive measures during the formulation of emulsions are important. Many naturally occurring and cost effective substances possess low oxidation tendencies and confer oxidative protection when used in emulsions. Additionally, certain preparatory methods should be employed to reduce or better control lipid peroxidation. Finally, emulsions must be evaluated for their oxidation susceptibility using the various techniques available. Careful attention to the preparation of emulsions and assessment of their oxidative stability will help produce safer emulsions without compromising efficacy.

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.

Effect of high-pressure homogenization preparation on mean globule size and large-diameter tail of oil-in-water injectable emulsions

The effect of different high pressure homogenization energy input parameters on mean diameter droplet size (MDS) and droplets with > 5 μm of lipid injectable emulsions were evaluated. All emulsions were prepared at different water bath temperatures or at different rotation speeds and rotor-stator system times, and using different homogenization pressures and numbers of high-pressure system recirculations. The MDS and polydispersity index (PI) value of the emulsions were determined using the dynamic light scattering (DLS) method, and large-diameter tail assessments were performed using the light-obscuration/single particle optical sensing (LO/SPOS) method. Using 1000 bar homogenization pressure and seven recirculations, the energy input parameters related to the rotor-stator system will not have an effect on the final particle size results. When rotor-stator system energy input parameters are fixed, homogenization pressure and recirculation will affect mean particle size and large diameter droplet. Particle size will decrease with increasing homogenization pressure from 400 bar to 1300 bar when homogenization recirculation is fixed; when the homogenization pressure is fixed at 1000 bar, the particle size of both MDS and percent of fat droplets exceeding 5 μm (PFAT5) will decrease with increasing homogenization recirculations, MDS dropped to 173 nm after five cycles and maintained this level, volume-weighted PFAT5 will drop to 0.038% after three cycles, so the "plateau" of MDS will come up later than that of PFAT5, and the optimal particle size is produced when both of them remained at plateau. Excess homogenization recirculation such as nine times under the 1000 bar may lead to PFAT5 increase to 0.060% rather than a decrease; therefore, the high-pressure homogenization procedure is the key factor affecting the particle size distribution of emulsions. Varying storage conditions (4-25°C) also influenced particle size, especially the PFAT5.

Understanding triglyceride levels related to intravenous fat administration

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

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.

Assessment of the physicochemical stability of all-in-one parenteral emulsions for neonates according to USP specifications

BACKGROUND

The purpose of this study was to describe the methodology to assess the stability of all-in-one (AIO) parenteral nutrition admixtures, containing glucose, proteins, and lipids, to the standards of U.S. Pharmacopoeia (USP <729>). The influence of calcium and commercially available lipid emulsions and amino acid solutions were also examined.

METHODS

Four batches of 5 AIO admixtures containing calcium were compounded with commercially available lipid emulsions and amino acid solutions. Two of them contained calcium. Their stability was tested under conditions simulating clinical use. All the admixtures were assessed for criteria set by the USP <729>: (1) mean droplet diameter (MDD) and (2) percentage of volume weighted particles with diameter > 5 μm (PFAT5).

RESULTS

All admixtures were within the specifications set by the USP with respect to the MDD at 0, 24, and 48 hours, but only those batches lacking calcium met the benchmarks set by the pharmacopoeia, with respect to PFAT5, on the day of preparation.

CONCLUSIONS

The presence of calcium destabilized the admixtures, while the use of different commercial ingredients altered the admixtures' characteristics. Only 1 batch of the AIO admixtures studied was found to be compliant with USP <729> standards.

Arginyl-glutamine dipeptide or docosahexaenoic acid attenuate hyperoxia-induced lung injury in neonatal mice

OBJECTIVES

Supplementation studies of glutamine, arginine, and docosahexaenoic acid (DHA) have established the safety of each of these nutrients in neonates. However, the potential for a more stable and soluble dipeptide, arginyl-glutamine (Arg-Gln) or DHA, a long-chain ω-3 fatty acid with anti-inflammatory properties, to exert benefits on hyperoxia-induced lung injury has not to our knowledge been investigated. The aim of this study was to investigate whether Arg-Gln dipeptide or DHA could attenuate markers of injury and inflammation in neonatal mouse lungs exposed to hyperoxia.

METHODS

Seven-day-old mouse pups were placed with their dams in 75% oxygen for 5 d. After 5 d of hyperoxic exposure (postnatal days 7-12), pups were removed from hyperoxia and allowed to recover in atmospheric conditions for 5 d (postnatal days 12-17). Mouse pups received Arg-Gln (5 g · kg⁻¹ · d⁻¹) or DHA (5 g · kg⁻¹ · d⁻¹) or saline orally from postnatal days 12 through 17. Histologic changes, myeloperoxidase, lactate dehydrogenase, inflammatory cytokines, and nuclear factor-κB inhibitor levels were checked in each group.

RESULTS

The Arg-Gln and DHA prevented the development of key markers of injury, including histologic changes, myeloperoxidase, lactate dehydrogenase, and inflammatory cytokines interleukin-6 and C-X-C motif ligand 1 (CXCL1)/keratinocyte-derived chemokine (KC). The highly beneficial effects of Arg-Gln on the reversal of oxygen-induced lung damage was associated with restoration of levels of nuclear factor-κB inhibitor.

CONCLUSION

The Arg-Gln and DHA, with protective effects on hyperoxic lung injury in neonatal mice, are promising nutritional adjuncts that may prevent lung damage owing to oxygen toxicity in infants.

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.

Lipid destabilisation in a ternary admixture for paediatric parenteral nutrition due to heparin and trigger factors

The preparation of paediatric parenteral nutrition admixtures varies greatly. There is still a clear lack of consensus on many points. These points include the use of organic or inorganic phosphate or calcium salts, preparing binary or ternary mixtures, the type of lipid used, and the addition or suppression of heparin or carnitine, etc. The process must be standardised in order to guarantee that prepared mixtures will be stable. However, there is still no information on how to predict their stability with any degree of precision, particularly for ternary mixtures. For that reason, any change applied may trigger a destabilisation process that places patient safety at risk. We describe a case of a ternary paediatric parenteral nutrition admixture in which creaming was observed. We indicate the factors that gave rise to this phenomenon and the measures taken to avoid it.

Arginyl-glutamine dipeptide or docosahexaenoic acid attenuates hyperoxia-induced small intestinal injury in neonatal mice

BACKGROUND AND OBJECTIVE

Supplementation studies of glutamine, arginine, and docosahexaenoic acid (DHA) have established the safety of each of these nutrients in neonates; however, the potential for a more stable and soluble dipeptide, arginyl-glutamine (Arg-Gln) or DHA with anti-inflammatory properties, to exert benefits on hyperoxia-induced intestinal injury has not been investigated. Arg-Gln dipeptide has been shown to prevent retinal damage in a rodent model of oxygen-induced injury. The objective of the present study was to investigate whether Arg-Gln dipeptide or DHA could also attenuate markers of injury and inflammation to the small intestine in this same model.

METHODS

Seven-day-old mouse pups were placed with their dams in 75% oxygen for 5 days. After 5 days of hyperoxic exposure (P7-P12), pups were removed from hyperoxia and allowed to recover in atmospheric conditions for 5 days (P12-P17). Mouse pups received Arg-Gln (5g·kg·day) or DHA (5g·kg·day) or vehicle orally started on P12 through P17. Distal small intestine (DSI) histologic changes, myeloperoxidase (MPO), lactate dehydrogenase (LDH), inflammatory cytokines, and tissue apoptosis were evaluated.

RESULTS

Hyperoxic mice showed a greater distortion of overall villus structure and with higher injury score (P<0.05). Arg-Gln dipeptide and DHA supplementation groups were more similar to the room air control group. Supplementation of Arg-Gln or DHA reduced hyperoxia-induced MPO activity (P<0.05). Supplementation of Arg-Gln or DHA returned LDH activity to the levels of control. Hyperoxia induced apoptotic cell death in DSIs, and both Arg-Gln and DHA reversed this effect (P<0.05).

CONCLUSIONS

Supplementation with either Arg-Gln or DHA may limit some inflammatory and apoptotic processes involved in hyperoxic-induced intestinal injury in neonatal mice.

Fish oil containing intravenous lipid emulsions in parenteral nutrition-associated cholestatic liver disease

PURPOSE OF REVIEW

Lipid emulsions containing fish oils have been proposed to improve parenteral nutrition associated cholestasis (PNAC), a very serious complication of prolonged parenteral nutrition occurring particularly in infants and children with intestinal failure. Here, we summarize current data.

RECENT FINDINGS

The cause of PNAC is multifactorial. Prevention is possible by appropriate management, surgical procedures, infection prevention, and optimal parenteral nutrition management. Plausible hypotheses and experimental data support potential benefits of fish oils for treatment and prevention of PNAC. Improvement of PNAC over weeks and months has been reported in observational case studies in part of the children who received parenteral lipids with fish oil, but similar improvements also occurred by withholding or reducing standard lipid emulsions. No controlled trials are available that would allow final conclusions on efficacy and safety of fish oil-based emulsions in PNAC. Concerns exist regarding possible untoward effects and an inadequate supply of n-6 fatty acids with parenteral fish oil only. First data from controlled trials with mixed lipid emulsions containing partly fish oil suggest safety in infants and children and some possible benefits for liver function.

SUMMARY

The observed improvement of PNAC on parenteral lipids with fish oil deserves further exploration. No controlled trials are available, nutritional adequacy and safety of 100% fish oil emulsions are not adequately documented, and currently their use cannot be considered standard care. First data on mixed lipid emulsions with some fish oil are encouraging, and their effects in PNAC should also be explored.