Parenteral Lipid Emulsions Research Articles

Parenteral fish oil lipid emulsion use in adults: a case series and review from an intestinal failure referral center.

Intestinal failure-associated liver disease (IFALD) is a complication of long-term PN use, attributed to the use of ω-6 injectable lipid emulsions (ILE). Fish oil (FO) ILE have been successful in reversing liver injury in neonates. Evidence for pure FO ILE use in adult patients is limited. Case series of the use of FO lipid emulsions in adults with IFALD from the University of Chicago PN registry. Analysis of medical charts and PN formulations was performed. Three cases of IFALD treated with FO ILE were identified. The first case was a 30-year-old man with short bowel syndrome (SBS), hyperbilirubinemia, and biopsy-proven IFALD. Following a change from a soy lipid emulsion to FO lipid emulsion, his liver tests rapidly improved and remained stable over 202 weeks of use. The second case was a 76-year-old woman with intestinal failure (IF) due to a frozen bowel. A change from a soy ILE to a composite lipid and later to a pure FO ILE did not result in improvement in her liver tests. The third case was a 28-year-old man with SBS and biopsy-proven IFALD. Change to a composite ILE and subsequently FO lipid emulsion resulted in a gradual improvement in liver tests. No clinical essential fatty acid (EFA) deficiencies were identified during treatment. FO ILE may be effective in the treatment of adult patients with cholestatic IFALD. Use is safe with no EFA deficiencies detected in up to 4 years of use.

Comparative effectiveness of two lipid emulsions in preventing retinopathy of prematurity in preterm infants requiring parenteral nutrition

ObjectivesThe main aim was to compare the effects of 2 parenteral lipid emulsions on retinopathy of prematurity (ROP) incidence, severity, and need for treatment. Secondary aim was to compare the effect on weight gain in the first 6 weeks of life. MethodsSingle-center, observational, retrospective study analyzing preterm infants with a gestational age (GA) <31 weeks and a birth weight <1251 g born between April 2015 and December 2018. The infants' medical records were reviewed to collect clinical data. Parenteral nutrition (PN) details were obtained from the hospital pharmacy database. ResultsIn total, 180 patients were included: 90 received ClinOleic® and 90 received SMOFlipid®. No significant differences were observed for the incidence of ROP (40% in ClinOleic® group and 41% in SMOFlipid® group, p=.88) or ROP requiring treatment (4% and 10%, respectively, p=.152). Weekly weight gain was similar in the 2 groups. ConclusionsThis study showed no difference between the 2 groups regarding ROP, ROP requiring treatment, or weekly weight gain in the first 6 weeks of life.

Impact of lipid emulsions in parenteral nutrition on platelets: a literature review.

Lipid emulsions are essential components of parenteral nutrition solutions that provide energy and essential fatty acids. The complexity of the formulations of lipid emulsions may lead to adverse outcomes such as platelet reactivity and changes in platelet aggregation and related coagulation. Platelets are responsible for haemostasis; they activate and demonstrate morphological changes upon extracellular factors to maintain blood fluidity and vascular integrity. Although parenteral nutrition lipid emulsions are generally found safe with regard to modulation of platelet activity, studies are still accumulating. Thus, this review aims to investigate platelet-related changes by parenteral nutrition lipid emulsions in human studies. Studies have pointed out patients at risk of bleeding and increased platelet aggregation responses due to the administration of lipid emulsions. Lipid emulsions may further benefit patients at high risk of thrombosis due to anti-thrombotic effects and should be cautiously used in patients with thrombocytopenia. The reported platelet-related changes might be associated with the fatty acid change in the plasma membranes of platelets following changes in platelet synthesis and plasma levels of eicosanoids. In conclusion, studies investigating platelets and parenteral nutrition should be supported to minimize the adverse effects and to benefit from the potential protective effects of parenteral nutrition lipid emulsions.

Effect of a parenteral fish-oil-containing lipid emulsion on liver lipid perioxidation and antioxidative defenses in Lewis rats.

Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), naturally abundant in fish oil (FO), are known for their anti-inflammatory and potential antioxidant properties. The aim in this article is to evaluate the effect of the infusion of a parenteral FO-containing lipid emulsion on markers of liver lipid peroxidation and oxidative stress in rats undergoing central venous catheterization (CVC). After 5-day acclimatization, adult Lewis rats (n = 42) receiving a 20-g/day AIN-93M oral diet were randomly subdivided into four groups: (1) basal control (BC) (n = 6), without CVC or LE infusion; (2) SHAM (n = 12), with CVC but without LE infusion; (3) soybean oil (SO)/medium-chain triglyceride (MCT) (n = 12), with CVC and receiving LE without FO (4.3 g/kg fat); and (4) SO/MCT/FO (n = 12), with CVC and receiving LE containing 10% FO (4.3 g/kg fat). Animals from the BC group were euthanized immediately after acclimatization. The remaining groups of animals were euthanized after 48 or 72 h of surgical follow-up to assess profiles of liver and plasma fatty acids by gas chromatography, liver gene transcription factor Nrf2, F2-isoprostane lipid peroxidation biomarker, and the antioxidant enzymes glutathione peroxidase (GPx), superoxide dismutase (SOD), and catalase (CAT) by enzyme-linked immunosorbent assay. R program (version 3.2.2) was utilized for data analysis. Compared with the other groups, liver EPA and DHA levels were higher in the SO/MCT/FO group, which also showed the highest liver Nrf2, GPx, SOD, and CAT levels and lower liver F2-isoprostane (P < 0.05). Experimental delivery of FO via EPA and DHA sources in a parenteral LE was associated with a liver antioxidant effect.

A secondary Outcome Analysis of a Randomized Trial Using a Mixed Lipid Emulsion Containing Fish Oil in Infants with Extremely Low Birth Weight: Cognitive and Behavioral Outcome at Preschool Age

To evaluate the impact of a parenteral lipid emulsion containing fish oil compared with a soybean oil based-lipid emulsion on the cognitive outcome and behavior of preschool children with extremely low birth weight. This was a retrospective secondary outcome analysis of a randomized controlled trial performed between June 2012 and June 2015. Infants with extremely low birth weight received either a mixed (soybean oil, medium chain triglycerides, olive oil, fish oil) or a soybean oil-based lipid emulsion for parenteral nutrition. Data from the Kaufman Assessment Battery for Children II, the Child Behavior Checklist 1.5-5, and anthropometry were collected from medical charts at 5.6years of age. At discharge, 206 of the 230 study participants were eligible. At 5years 6months of age, data of 153 of 206 infants (74%) were available for analysis. There were no significant differences in Kaufman Assessment Battery for Children II scores for Sequential/Gsm, Simultaneous/Gv, Learning/Glr, and Mental Processing Index (mixed lipid: median, 97.5 [IQR, 23.5]; soybean oil: median, 96 [IQR, 19.5]; P=.43) or Child Behavior Checklist 1.5-5 scores for internalizing problems, externalizing problems, or total problems (mixed lipid: median, 37 [IQR, 12.3]; soybean oil: median, 37 [IQR, 13.5]; P=.54). A RandomForest machine learning regression analysis did not show an effect of type of lipid emulsion on cognitive and behavioral outcome. Parenteral nutrition using a mixed lipid emulsion containing fish oil did not affect neurodevelopment and had no impact on child behavior of infants with extremely low birth weights at preschool age. ClinicalTrials.gov: NCT01585935.

Chylopericardium or contamination by injectable lipid emulsion?

Effusions can show some surprises. We document the case of a fourteen-month-old male patient with short-bowel syndrome, hospitalized in a cardiology unit, receiving a chronic parenteral nutrition by a Broviac® catheter. The patient presented several thrombosis following iterative catheter replacements. In parallel with superior vena cava plasty, a right intra-atrial Broviac® catheter was placed in the absence of other peripheral venous accesses. This device has a cutaneous exit site to allow for infusion of a hyperosmolar lipid emulsion. Seven days later, a milky liquid was secreted from pericardial/mediastinal redon. A gel lipoprotein electrophoresis of the fluid suggested a preliminary diagnosis of chylopericardium. However, biochemical testing of certain analytes evoked a parenteral nutrition-related pericardial effusion and a possible pseudochyloperitoneum caused by the shearing of a migrated Broviac® in pericardium. The patient, on a fat-free diet, was admitted to the ICU to drain the effusion and reposition the catheter, with success. In the light of new datas on the interference of parenteral lipid emulsions with the lipoproteins gel electrophoresis, we will try to determine whether the apparent presence of chylomicrons in the gel would be the sign of a lesion of the lymphatic system, or rather the result of a contamination by artificial chylomicron in the lipid emulsion, if not the sign of contaminated blood. In our article, we highlight several considerations in identifying and confirming cases of pericardial effusion, such as chylopericardium and parenteral nutrition-related one, as well as points concerning the use of lipid emulsions for pediatric patients with short-bowel syndrome.

Process Analytical Technology for the Production of Parenteral Lipid Emulsions According to Good Manufacturing Practices

The good manufacturing practices (GMP) and process analytical technology (PAT) initiatives of the US Food and Drug Administration, in conjunction with International Council for Harmonisation (ICH) quality guidelines Q8, Q9, and Q10, ensure that manufacturing processes for parenteral formulations meet the requirements of increasingly strict regulations. This involves the selection of suitable process analytics for process integration and aseptic processing. In this article, we discuss the PAT requirements for the GMP-compliant manufacturing of parenteral lipid emulsions, which can be used for clinical nutrition or for the delivery of lipophilic active ingredients. There are risks associated with the manufacturing processes, including the potential for unstable emulsions and the formation of large droplets that can induce embolisms in the patient. Parenteral emulsions are currently monitored offline using a statistical approach. Inline analytics, supplemented by measurements of zeta potential, could minimize the above risks. Laser scanning technology, ultrasound attenuation spectroscopy, and photo-optical sensors combined with image analysis may prove to be useful PAT methods. In the future, these technologies could lead to better process understanding and control, thus improving production efficiency.

Neurodevelopmental Outcome of Extremely Low Birth Weight Infants with Cholestasis at 12 and 24 Months

Introduction: The aims of the study were to describe the neurodevelopmental outcome of extremely low birth weight (ELBW) infants with parenteral nutrition-associated cholestasis (PNAC) and to assess whether PNAC is associated with adverse neurodevelopmental outcome. Methods: The study is a secondary analysis of controlled trial (June 2012–October 2017) on PNAC incidence in ELBW infants receiving two different parenteral lipid emulsions (mixed lipid emulsion containing fish oil vs. soybean oil-based). Neurodevelopmental follow-up at 12- and 24-month corrected age was compared in infants with and without PNAC. A machine learning-based regression analysis was used to assess whether PNAC was associated with adverse neurodevelopmental outcome. Results: For assessment of neurodevelopmental outcome (Bayley-III), 174 infants were available at 12-month (PNAC: n = 21; no PNAC: n = 153) and 164 infants at 24-month (PNAC: n = 20; no PNAC: n = 144) corrected age. The neurodevelopment of ELBW infants with PNAC was globally delayed, with significantly lower cognitive, language, and motor scores at both 12- and 24-month corrected age. Regression analyses revealed that PNAC was associated with an adverse motor outcome. Conclusion: ELBW infants with PNAC are at increased risk for adverse neurodevelopmental outcome.

Filtering Out the Facts: Recommendations to Optimize Performance of In-Line Filters for Parenteral Nutrition and Injectable Lipid Emulsion Infusions.

The use of an in-line, 1.2-μm filter is recommended for the intravenous (IV) infusion of parenteral nutrition (PN), also known as 3-in-1, total nutrient admixture (TNA), or all-in-one, and injectable lipid emulsions (ILEs) infused alone through a separate IV line. While filtration of TNA was mandated in 1994 to improve patient safety, the recommendation for filtering lipid emulsions alone is relatively new and has not been adopted by all clinicians. In addition, literature references and postmarket surveillance data cite the occurrence of infusion pump occlusion alarms, which may be indicative of a clogged filter. The following review article provides an overview of filter recommendations for PN and ILE, describes the challenges of filtration with PN and ILE, and includes recommendations to minimize pump occlusion alarms that may occur from a clogged filter.

Omega-6 sparing effects of parenteral lipid emulsions\u2014an updated systematic review and meta-analysis on clinical outcomes in critically ill patients

BackgroundParenteral lipid emulsions in critical care are traditionally based on soybean oil (SO) and rich in pro-inflammatory omega-6 fatty acids (FAs). Parenteral nutrition (PN) strategies with the aim of reducing omega-6 FAs may potentially decrease the morbidity and mortality in critically ill patients.MethodsA systematic search of MEDLINE, EMBASE, CINAHL and CENTRAL was conducted to identify all randomized controlled trials in critically ill patients published from inception to June 2021, which investigated clinical omega-6 sparing effects. Two independent reviewers extracted bias risk, treatment details, patient characteristics and clinical outcomes. Random effect meta-analysis was performed.Results1054 studies were identified in our electronic search, 136 trials were assessed for eligibility and 26 trials with 1733 critically ill patients were included. The median methodologic score was 9 out of 14 points (95% confidence interval [CI] 7, 10). Omega-6 FA sparing PN in comparison with traditional lipid emulsions did not decrease overall mortality (20 studies; risk ratio [RR] 0.91; 95% CI 0.76, 1.10; p = 0.34) but hospital length of stay was substantially reduced (6 studies; weighted mean difference [WMD] − 6.88; 95% CI − 11.27, − 2.49; p = 0.002). Among the different lipid emulsions, fish oil (FO) containing PN reduced the length of intensive care (8 studies; WMD − 3.53; 95% CI − 6.16, − 0.90; p = 0.009) and rate of infectious complications (4 studies; RR 0.65; 95% CI 0.44, 0.95; p = 0.03). When FO was administered as a stand-alone medication outside PN, potential mortality benefits were observed compared to standard care.ConclusionOverall, these findings highlight distinctive omega-6 sparing effects attributed to PN. Among the different lipid emulsions, FO in combination with PN or as a stand-alone treatment may have the greatest clinical impact.Trial registration PROSPERO international prospective database of systematic reviews (CRD42021259238).Graphical abstract

False anemia due to total parenteral nutrition and lipid emulsion contamination.

False anemia due to total parenteral nutrition and lipid emulsion contamination.

Serum docosahexaenoic acid levels are associated with brain volumes in extremely preterm born infants.

Docosahexaenoic acid (DHA) and arachidonic acid (AA) are important for fetal brain growth and development. Our aim was to evaluate the association between serum DHA and AA levels and brain volumes in extremely preterm infants. Infants born at <28 weeks gestational age in 2013-2015, a cohort derived from a randomized controlled trial comparing two types of parenteral lipid emulsions, were included (n = 90). Serum DHA and AA levels were measured at postnatal days 1, 7, 14, and 28, and the area under the curve was calculated. Magnetic resonance (MR) imaging was performed at term-equivalent age (n = 66), and volumes of six brain regions were automatically generated. After MR image quality assessment and area under the curve calculation, 48 infants were included (gestational age mean [SD] 25.5 [1.4] weeks). DHA levels were positively associated with total brain (B = 7.966, p = 0.012), cortical gray matter (B = 3.653, p = 0.036), deep gray matter (B = 0.439, p = 0.014), cerebellar (B = 0.932, p = 0.003), and white matter volume (B = 3.373, p = 0.022). AA levels showed no association with brain volumes. Serum DHA levels during the first 28 postnatal days were positively associated with volumes of several brain structures in extremely preterm infants at term-equivalent age. Higher serum levels of DHA in the first 28 postnatal days are positively associated with brain volumes at term-equivalent age in extremely preterm born infants. Especially the most immature infants suffer from low DHA levels in the first 28 postnatal days, with little increase over time. Future research is needed to explore whether postnatal fatty acid supplementation can improve brain development and may serve as a nutritional preventive and therapeutic treatment option in extremely preterm infants.

Effects of different lipid emulsions on serum adipokines, inflammatory markers and mortality in critically ill patients with sepsis: A prospective observational cohort study

Intravenous lipid emulsions in parenteral nutrition may cause different metabolic responses and immune effects in critically ill patients with sepsis. The aim of this study is to investigate the effects of different lipid emulsions on changes in concentrations of adipokine and cytokine and their relationship with mortality in patients. Patients enrolled in this prospective, single-center, observational cohort study, were estimated to require more than ten days of parenteral nutrition. They were treated with soybean oil-based or olive oil-based parenteral lipid emulsions. Adipokine and cytokine concentrations of septic patients were determined at enrollment and ten days after, in accordance with the diagnostic criteria of SEPSIS-3. The concentrations levels were measured in an enzyme-linked immunosorbent assay. Mortality was analyzed using the Kaplan-Meier method and Cox regressions. Over a 25-month period, 145 patients were assessed for eligibility and consequently, 40 patients were analyzed. On admission, both groups had comparable physiological scores, comorbidities, malnutrition risk, anthropometric measurements, metabolic/hematologic biomarkers and concentrations of adipokines and cytokines (p>.05). Serum leptin, resistin, and cytokines (IL-6, IL-10, IL-1β and TNF-α) decreased significantly in the entire cohort over ten days following sepsis (p<.05). Serum resistin decreased in both olive oil-based and soybean oil-based lipid emulsions groups. Serum adiponectin only decreased in soybean oil-based lipid emulsions group (p<.05). There was association between survival and percentage changes in adiponectin, resistin and visfatin concentrations (log rank test: p<.05). Adipokine and cytokine responses are affected by medical nutritional therapy in the sepsis process and adipokines may represent functional prognostic biomarkers in critically ill patients with sepsis.

Depletion and enrichment of phytosterols in soybean oil lipid emulsions directly associate with serum markers of cholestasis in preterm parenteral nutrition-fed pigs.

Clinical reports show a positive correlation between phytosterol concentrations and severity of cholestatic liver disease markers in infants during long-term administration of parenteral lipid emulsions. Establishing a causal link between phytosterols and cholestasis has been complicated by confounding factors of lipid emulsion load, fatty acid composition, and vitamin E in many of these studies. The goal of this study is to determine whether altering the phytosterol concentration within a common soybean oil-based emulsion will alter the onset and severity of cholestasis in parenterally fed preterm piglets. Preterm piglets were administered, for 21 days, either enteral nutrition (ENT) or parenteral nutrition (PN) prepared from a soybean oil-based emulsion containing either 24.0% (depleted [DEP]), 100% (Intralipid; normal phytosterol [NP] concentration), or 144% (enriched [ENR]) total phytosterol concentration. At the end of the study, plasma and liver phytosterol concentrations were highest in the ENR group, followed by NP and then DEP and ENT. Serum direct bilirubin, serum bile acids, and γ-glutamyltransferase were higher in the ENR and NP groups compared with either DEP or ENT groups. All PN lipid groups showed evidence of mild hepatic steatosis but no change in hepatic expression of proinflammatory cytokines or Farnesoid X receptor target genes. The increase in serum direct bilirubin was lower in the DEP group vs the lipid emulsions with normal or ENR phytosterols. Our results provide additional evidence that phytosterols are linked to an increase in serum markers of cholestasis in preterm PN-fed pigs.

Impact of Parenteral Lipid Emulsion Components on Cholestatic Liver Disease in Neonates

Total parenteral nutrition (TPN) is a life-saving intervention for infants that are unable to feed by mouth. Infants that remain on TPN for extended periods of time are at risk for the development of liver injury in the form of parenteral nutrition associated cholestasis (PNAC). Current research suggests the lipid component of TPN is a factor in the development of PNAC. Most notably, the fatty acid composition, vitamin E concentration, and presence of phytosterols are believed key mediators of lipid emulsion driven PNAC development. New emulsions comprised of fish oil and medium chain triglycerides show promise for reducing the incidence of PNAC in infants. In this review we will cover the current clinical studies on the benefit of fish oil and medium chain triglyceride containing lipid emulsions on the development of PNAC, the current constituents of lipid emulsions that may modulate the prevalence of PNAC, and potential new supplements to TPN to further reduce the incidence of PNAC.

Is There an Advantage in Enriching Parenteral Lipid Emulsions Containing Fatty Acids From Fish Oil With Medium-Chain Triglycerides? A Study on Body Pool Concentrations of ω-3 Fatty Acids in Lewis Rats.

The addition of medium-chain triglycerides (MCTs) into parenteral lipid emulsions rich in fatty acids from fish oil (FOLEs) has been shown to improve their clearance and extrahepatic uptake. We assessed whether this effect could favor the leukocyte uptake of ω-3 polyunsaturated fatty acids (PUFAs) for immunomodulatory purposes METHODS: Following 5-day adaptation in metabolic cages, 42 male Lewis rats fed with AIN-93M chow were killed (baseline control group [BC]) or submitted to central venous catheterization and distributed into (1) surgical control group without parenteral infusion (chow group), (2) test emulsion (MCT/LCT/FO) group with the parenteral infusion of a FOLE containing 40% MCT, and (3) control emulsion group (LCT/FO) with the parenteral infusion of an FOLE without MCT. The 2 FOLEs had similar ω-3 PUFA contents and ω-6/ω-3 PUFA ratios and were infused during 48 and 72 hours. Concentrations of ω-3 and ω-6 PUFAs in plasma, liver, and blood mononuclear and polymorphonuclear leukocytes were assessed by gas chromatography RESULTS: In both FOLE groups, leukocyte concentrations of ω-3 PUFAs peaked after 48 hours' infusion (vs BC). At this time point, plasma concentrations of ω-3 PUFAs were higher in MCT/LCT/FO group than in LCT/FO group and the opposite was found in the liver (P<.05), but no differences in PUFA concentrations were observed between these groups in leukocytes (P>.05) CONCLUSION: The ω-3 PUFAs provided by FOLEs rich in MCT were less incorporated by liver and remained more available for extrahepatic cell delivery, but this did not result in a clear benefit in increasing their incorporation by peripheral leukocytes.

Parenteral lipid emulsions induce unique ileal fatty acid and metabolomic profiles but do not increase the risk of necrotizing enterocolitis in preterm pigs

Exposure to parenteral lipid emulsions induces unique intestinal fatty acid and metabolomic profiles; however, these profiles are not linked to a difference in NEC risk in preterm pigs. Metabolomic and proteomic analyses provide mechanistic insights into NEC pathogenesis. Compared with healthy ileal tissue, metabolites in tryptophan metabolism and arachidonic acid-containing glycerophospholipids are increased in NEC tissue. Proteomic analysis differentiates NEC versus no NEC in the domains of tissue injury, glucose uptake, and chemokine signaling.

Infusion time for fish oil-containing parenteral emulsions in surgery: A study on ω-3 fatty acid dynamics in rats.

The aim of this study was to contribute to the design of specialized parenteral nutrition protocols in surgery by evaluating the dynamics of polyunsaturated fatty acid (PUFA) concentrations in different body pools after the infusion of fish oil-containing lipid emulsion (FOLE) in rats that had undergone surgical central venous catheterization (CVC). After 5-d adaptation in metabolic cages, 78 male Lewis rats (300-450 g) fed a standard diet were sacrificed (baseline control) or had only CVC (surgical control) or also received a 72-h infusion of a parenteral lipid emulsion with or without fish oil. The catheterized animals were sacrificed 0 (T0), 2 (T2), 6 (T6), and 12 h (T12) after the infusion ended. Gas chromatography was used to determine the concentrations of eicosapentaenoic (EPA), docosahexaenoic (DHA), and arachidonic (ARA) acids and the ω-3 to ω-6 ratio in plasma, liver, and blood leukocytes. Kruskal-Wallis and Wilcoxon tests were applied to plasma and liver data and descriptive analysis to leukocyte data. Plasma, liver, and leukocytes exhibited almost undetectable EPA and DHA and detectable ARA concentrations at baseline. Immediately after FOLE infusion (T0), these PUFAs changed in all pools, resulting in a higher ratio of ω-3 to ω-6 compared with rats with no FOLE infusion (P < 0.05). All these changes decreased over time, with residual effects remaining until T6 in plasma, T12 in liver, and only until T2 in leukocytes. Data from this study suggest that ω-3 PUFAs are cleared early after the end of FOLE infusion, mainly in leukocytes. This should be considered when FOLEs are applied for immunomodulatory purposes in surgery.

Effect of parenteral lipid emulsion on preterm infant PUFAs and their downstream metabolites

ObjectiveOxylipins synthesized by oxidation of long-chain polyunsaturated fatty acids (LCPUFAs) are bioactive downstream lipid mediators. The aim of this study was to describe oxylipin levels in preterm infants born 30 to 33 weeks’ gestation who were enrolled in a randomized controlled trial in which peripheral parenteral nutrition (P-PN), including lipid emulsion (containing soy, medium chain triglyceride, olive and fish oil), was compared with 10% glucose on growth during the transition to enteral feeds. MethodsOf the 92 infants randomized to the P-PN study, the first 72 (P-PN n = 34, control n = 38) had blood taken for fatty acid analyses. P-PN infants received parenteral nutrition including 3% protein, 8% glucose and 17% SMOFlipid® lipid (containing soy, medium chain triglyceride, olive and fish oil), and control infants 10% glucose. Both groups commenced enteral feeds when clinically stable. 32 oxylipins and 5 free fatty acids were screened (using ultra-high-performance liquid chromatography–tandem mass spectrometry), and 5 total LCPUFA were measured (using gas chromatography), on study days 1 (baseline), 2, 4, 7, 14 and 21. ResultsBoth total and free LA, ALA and EPA were significantly higher in the P-PN group compared with control over the first week of life. Whereas total AA was significantly lower and free DHA significantly higher over the same time period. All LA, ALA, EPA and four DHA derived oxylipins detected were significantly higher in the P-PN group compared with the control group during the first week of life, with three AA derived oxylipins significantly lower and one significantly higher. ConclusionsParenteral lipid emulsion resulted in a change in total and free fatty acids and related oxylipins with the profiles suggesting increased omega-6 driven inflammation. Further studies to investigate the association between the oxylipin levels and nutrition and to determine whether the oxylipin profiles influence the clinical outcome in preterm infants are warranted.

Improved HPLC method for the quantification of free fatty acids in parenteral lipid emulsions

Rationale: Total free fatty acid (FFA) concentration of oil-in-water (o/w) emulsions is a critical quality parameter and thus necessary to quantify. Here we present an improved method for the FFA measurement by HPLC with fluorescence detection that can distinguish between different fatty acid (FA) species, which will further enhance our understanding of underlying degradation mechanisms and thereby can foster the development of innovative lipid emulsions.