Intravenous Lipid Emulsions in Parenteral Nutrition

Fat malabsorption in short bowel syndrome: A review of pathophysiology and management

Fat malabsorption is central to the pathophysiology of short bowel syndrome (SBS). It occurs in patients with insufficient intestinal surface area and/or function to maintain metabolic and growth demands. Rapid intestinal transit and impaired bile acid recycling further contribute to fat malabsorption. A significant portion of patients require parenteral nutrition (PN) for their survival but may develop sepsis and liver dysfunction as a result. Despite advancements in the treatment of SBS, fat malabsorption remains a chronic issue for this vulnerable patient population. Peer-reviewed literature was assessed on the topic of fat malabsorption in SBS. Current management of patients with SBS involves dietary considerations, PN management, antidiarrheals, glucagon-like peptide 2 agonists, and multidisciplinary teams. Clinical trials have focused on improving intestinal fat absorption by facilitating fat digestion with pancreatic enzymes. Targeting fat malabsorption in SBS is a potential pathway to improving lifestyle and reducing morbidity and mortality in this rare disease.

Natural Fat Nanoemulsions for Enhanced Optical Coherence Tomography Neuroimaging and Tumor Imaging in the Second Near-Infrared Window

Optical coherence tomography (OCT) imaging mainly uses backscattered light to visualize the structural and functional information on biological tissues. In particular, OCT angiography can not only map the capillary networks but also capture the blood flow in the tissue microenvironment, making it a good candidate for neuroimaging and tumor imaging in vivo and in real time. To further improve the detection accuracy of cancer or brain disorders, it is essential to develop a natural and nontoxic contrast agent for enhanced OCT imaging in the second near-infrared (NIR-II) window. In this study, a superior biocompatible and highly scattering NIR-II fat nanoemulsion was constructed to improve OCT imaging contrast and depth for monitoring the vascular network changes of the cerebral cortex or tumor. In vivo experimental results demonstrated that a natural fat nanoemulsion can serve as an excellent probe for enhanced OCT neuroimaging and tumor imaging.

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.

Impact of Intravenous Fat Emulsion Choice on Candida Biofilm, Hyphal Growth, and Catheter-Related Bloodstream Infections in Pediatric Patients

BACKGROUND

Use of mixed-oil (MO) intravenous fat emulsion (IFE) was shown to inhibit Candida albicans biofilm formation and overall rate of catheter-related bloodstream infections (CR-BSIs) compared with soybean-oil (SO) IFE). We aimed to delineate this inhibitory mechanism and impact of IFE choice on distribution of fungal CR-BSIs.

METHODS

Transcriptional profiling was conducted on C. albicans grown in SO-IFE, MO-IFE, or SO-IFE with capric acid. Overexpression strains of shared down-regulated genes were constructed using a tetracycline-off system to assess hypha and biofilm formation in IFEs. A 5-year retrospective multicenter cohort study was performed to assess differences in CR-BSIs caused by Candida species based on the IFE formulation received in pediatric patients.

RESULTS

Genes significantly down-regulated in MO-IFE and SO-IFE with capric acid included CDC11, HGC1, and UME6. Overexpression of HGC1 or UME6 enabled filamentation in capric acid and MO-IFE. Interestingly, only overexpression of UME6 was sufficient to rescue biofilm growth in MO-IFE. MO-IFE administration was associated with a higher proportion of non-albicans Candida versus C. albicans CR-BSIs (42% vs 33%; odds ratio, 1.22 [95% confidence interval, .46-3.26]).

CONCLUSIONS

MO-IFE affects C. albicans biofilm formation and hyphal growth via a UME6-dependent mechanism. A numerical but not statistically significant difference in distribution of Candida spp. among CR-BSIs was observed.

Composite lipid emulsion use and essential fatty acid deficiency in pediatric patients with intestinal failure with high parenteral nutrition dependence: A retrospective cohort study

BACKGROUND

Reports of essential fatty acid deficiency (EFAD) in patients receiving parenteral nutrition (PN) and a composite lipid (mixed oil intravenous lipid emulsion [MO ILE]) are predominantly when managed by lipid restriction. The objective of this study was to determine the prevalence of EFAD in patients with intestinal failure (IF) who are PN dependent without lipid restriction.

METHODS

We retrospectively evaluated patients, ages 0-17 years, followed by our intestinal rehabilitation program between November 2020 and June 2021 with PN dependency index (PNDI) of >80% on a MO ILE. Demographic data, PN composition, PN days, growth, and plasma fatty acid profile were collected. A plasma triene-tetraene (T:T) ratio >0.2 indicated EFAD. Summary statistics and Wilcoxon rank sum test evaluated to compare between PNDI category and ILE administration (grams/kilograms/day). P < 0.05 was considered significant.

RESULTS

Twenty-six patients (median age, 4.1 years [interquartile range (IQR) = 2.4-9.6]) were included. The median duration of PN was 1367 days (IQR = 824-3195). Sixteen patients had a PNDI of 80%-120% (61.5%). Fat intake for the group was 1.7 g/kg/day (IQR = 1.3-2.0). The median T:T ratio was 0.1 (IQR = 0.1-0.2) with no values >0.2. Linoleic and arachidonic acid were low in 85% and 19% of patients, respectively; however, Mead acid was normal in all patients.

CONCLUSION

This report is the largest to date on the EFA status of patients with IF on PN. These results suggest that, in the absence of lipid restriction, EFAD is not a concern when using MO ILEs in children receiving PN for IF.

Patterns of lipid-injectable emulsion use in neonatal intensive care units across the United States: A multi-institution survey

BACKGROUND

Lipid-injectable emulsions (ILEs) are a necessity for neonates dependent on parenteral nutrition (PN). In this manuscript, we describe the patterns of ILE use in neonatal intensive care units (NICUs) in the United States (US).

METHODS

An electronic survey was sent to 488 NICUs across the US between December 2020 and March 2021. Survey fields included availability and utilization of various ILE in neonates.

RESULTS

The response rate was 22% (107 out of 488). Soybean oil ILE (SO-ILE) and soybean oil, medium-chain triglycerides, olive oil, fish oil ILE (SO, MCT, OO, FO-ILE) had similar availability (87% vs 86%, respectively), and SO, MCT, OO, FO-ILE was more commonly used (SO-ILE, 71% vs SO, MCT, OO, FO-ILE, 86%). Fish oil-ILE (FO-ILE) was used by 55% of centers. SO-ILE was most frequently used with PN and needs <4 weeks without cholestasis (79%). The most common reason for SO, MCT, OO, FO-ILE use was cholestasis (71%). ILE minimization was used by 28% of SO-ILE and 22% of SO, MCT, OO, FO-ILE users; 95% of these centers restrict SO, MCT, OO, FO-ILE to doses ≤2 g/kg/day. Twenty-two percent of centers started FO-ILE at direct bilirubin of >5 mg/dl.

CONCLUSION

The results of this survey reveal significant variability in ILE usage across the US. Lipid minimization with SO, MCT, OO, FO-ILE and initiation of FO-ILE for cholestasis at higher bilirubin thresholds are prevalent. Such reports are crucial for a better understanding of ILE use in the NICU and in future ILE development.

Accidental lipid overdose in a preterm infant: A case report

BACKGROUND

Intravenous lipid emulsions (ILEs) provide essential fatty acids during parenteral nutrition (PN). Serious adverse events including death can occur from overdose. We report an accidental overdose in a preterm infant.

METHOD

On Day 2 of life, a 29-week gestational age (GA) twin was accidentally given 47.5 mL of Intralipid20% (≈3x daily amount) in 50-minutes.

RESULTS

No apparent clinical deterioration occurred, although blood samples were lipaemic. Outcomes at 2 years corrected GA were similar to that of his twin. Service changes were made to infusion packaging and administration to avoid similar errors.

CONCLUSIONS

Medication errors in neonates are unfortunately common. Published articles usually focus on poor outcomes, which can increase the distress for parents of children where errors have occurred. Publishing the full spectrum of outcomes instead allows parents and professionals to be aware of all possibilities and lessons learnt, even if serious harm was avoided.

Comparison of catheter-related bloodstream infection rates in pediatric patients receiving parenteral nutrition with soybean oil-based intravenous fat emulsion versus a mixed oil fat emulsion

STUDY OBJECTIVE

To compare rates of catheter-related bloodstream infections (CR-BSI) in pediatric patients who received parenteral nutrition (PN) with either soybean oil-based intravenous fat emulsion (SO-IFE) or mixed oil-IFE (MO-IFE). We hypothesized that the use of MO-IFE would be independently associated with reduced infection rates compared with SO-IFE.

DESIGN

Retrospective cohort study.

SETTING

Tertiary referral children's hospital and its associated gastrointestinal rehabilitation clinic (01 January, 2015-31 July, 2019).

PATIENTS

Days of IFE exposure were counted for patients aged <18 years on IFE initiated during the review period, who had a central venous catheter (CVC) placed for PN administration, received IFE at least three times weekly, and for at least 7 days.

MEASUREMENTS

The primary outcome included total and categorical CR-BSI rates expressed as the average with standard error (SE) number of infections per 1000 fat emulsion days. The following categories were specified: Candida albicans, non-albicans Candida spp., coagulase-negative Staphylococcus (CoNS), Enterobacterales, methicillin-resistant S. aureus, methicillin-susceptible S. aureus, and Pseudomonadales. Average infection rate comparisons were quantified as incidence rate ratios (IRR) using generalized linear mixed modeling with a Poisson distribution.

MAIN RESULTS

Seven hundred and forty-three SO-IFE and 450 MO-IFE exposures were reviewed from 1131 patients, totaling 37,599 and 19,796 days of therapy, respectively. From those found significantly different, the average rate of infections with CoNS was 3.58 (SE 0.5)/1000 days of SO-IFE and 1.39 (SE 0.45)/1000 days of MO-IFE (IRR [95% confidence interval, CI]: 0.27 [0.16-0.46]; p < 0.01). Total average rates of infection were 7.33 (SE 0.76)/1000 days of SO-IFE and 4.52 (SE 0.75)/1000 days of MO-IFE (IRR [95% CI]: 0.60 [0.44-0.81]; p < 0.01). Other factors associated with higher infection rates include female gender, neonatal age, and inpatient-only IFE exposure.

CONCLUSIONS

Receipt of MO-IFE was associated with lower rates of CoNS and total CR-BSIs compared with SO-IFE in pediatric patients. These findings could have major implications on IFE selection for pediatric patients receiving PN.

Development of consensus recommendations for the management of post-operative chylothorax in paediatric CHD

OBJECTIVE

A standardised multi-site approach to manage paediatric post-operative chylothorax does not exist and leads to unnecessary practice variation. The Chylothorax Work Group utilised the Pediatric Critical Care Consortium infrastructure to address this gap.

METHODS

Over 60 multi-disciplinary providers representing 22 centres convened virtually as a quality initiative to develop an algorithm to manage paediatric post-operative chylothorax. Agreement was objectively quantified for each recommendation in the algorithm by utilising an anonymous survey. "Consensus" was defined as ≥ 80% of responses as "agree" or "strongly agree" to a recommendation. In order to determine if the algorithm recommendations would be correctly interpreted in the clinical environment, we developed ex vivo simulations and surveyed patients who developed the algorithm and patients who did not.

RESULTS

The algorithm is intended for all children (<18 years of age) within 30 days of cardiac surgery. It contains rationale for 11 central chylothorax management recommendations; diagnostic criteria and evaluation, trial of fat-modified diet, stratification by volume of daily output, timing of first-line medical therapy for "low" and "high" volume patients, and timing and duration of fat-modified diet. All recommendations achieved "consensus" (agreement >80%) by the workgroup (range 81-100%). Ex vivo simulations demonstrated good understanding by developers (range 94-100%) and non-developers (73%-100%).

CONCLUSIONS

The quality improvement effort represents the first multi-site algorithm for the management of paediatric post-operative chylothorax. The algorithm includes transparent and objective measures of agreement and understanding. Agreement to the algorithm recommendations was >80%, and overall understanding was 94%.

A New Control Strategy for High-Pressure Homogenization to Improve the Safety of Injectable Lipid Emulsions

Intravenous lipid emulsions are biocompatible formulations used as clinical nutrition products and lipid-based delivery systems for sparingly soluble drugs. However, the particle-size distribution is associated with risks of embolism. Accordingly, the mean particle diameter (MPD) and particle-distribution tailing (characterized as the pFAT5 value) are critical quality attributes that ensure patient safety. Compliance with the limits stated in the United States Pharmacopoeia is ensured by high-pressure homogenization, the final step of the manufacturing process. The US Food and Drug Administration’s Quality-by-Design approach requires a control strategy based on deep process understanding to ensure that products have a consistent and predefined quality. Here we investigated the process parameters of a jet-valve high-pressure homogenizer, specifically their effect on the MPD, pFAT5 value and droplet count (determined by microscopy) during the production of a Lipofundin MCT/LCT 20% formulation. We provide deep insight into droplet breakup and coalescence behavior when varying the process pressure, emulsion temperature and number of homogenization cycles. We found that high shear forces are not required to reduce the pFAT5 value of the particle distribution. Finally, we derived a control strategy for a rapid and cost-efficient two-cycle process that ensures patient safety over a large control space.

Evaluation of Emulsifying Ability of Phospholipids by Langmuir Monolayers and Stability of High Oil Ratio O/W Emulsions

High oil ratio fat emulsion injections are prone to poor emulsification, rapid creaming, and other quality problems; therefore, the selection of emulsifiers with high emulsifying ability is crucial for the production of fat emulsions. The existing methods used to evaluate the emulsifying ability of emulsifier are to evaluate the emulsifying ability from the emulsifier itself. In the study, Langmuir monolayer selected the most miscible phospholipid with oil phase from the alternative three phospholipids by studying the molecular interaction between oil phase and phospholipid at the air/water interface. The miscibility and thermodynamic stability analyses of the different oil phase/phospholipid mixed monolayers were performed, and the data from [Formula: see text] and [Formula: see text] concluded that all three oil phases had the strongest molecular interaction with E80 and the best miscibility. The emulsions were then prepared and analyzed by the results of particle size, ζ-potential, and stability of the emulsions, where the surface free energy in the stability test echoed the results reflected by the [Formula: see text] values in the thermodynamic stability test. These results indicate that Langmuir monolayers can be used to study the interaction between oil phase and emulsifier, thus providing new ideas for evaluating the emulsifying ability of phospholipids.

Hepatic Function in Premature Lambs Supported by the Artificial Placenta and Total Parenteral Nutrition

The artificial placenta (AP) promotes organ development and reduces organ injury in a lamb model of extreme prematurity. This study evaluates hepatic outcomes after AP support with total parenteral nutrition (TPN) administration. Premature lambs (116-121 days estimated gestational age; term = 145) were cannulated for 7 days of AP support. Lambs received TPN with SMOFlipid (n = 7) or Intralipid (n = 5). Liver function and injury were compared between the two groups biochemically and histologically. Groups were compared by ANOVA with Tukey's multiple comparisons or linear-mixed effects models. From baseline to day 7, total bilirubin (Intralipid 2.6 ± 2.3 to 7.9 ± 4.4 mg/dl; SMOFlipid 0.3 ± 0.1 to 5.5 ± 2.3 mg/dl), alanine aminotransferase, and gamma-glutamyl transferase increased in both groups ( p < 0.001 for all). Direct bilirubin (0.3 ± 0.2 to 1.8 ± 1.4 mg/dl; p = 0.006) and AST (27 ± 5 to 309 ± 242 mg/dl; p < 0.001) increased in SMOFlipid group (not measured in Intralipid group). On liver histology, Intralipid showed more cholestasis than SMOFlipid; both groups showed more than tissue controls. The Intralipid group alone showed hepatocyte injury and had more congestion than controls. Lambs supported by the AP with TPN administration maintain normal hepatic function and sustain minimal hepatic injury. SMOFlipid is associated with decreased cholestasis and hepatic injury versus Intralipid.

Treatment of preadipocytes with fish oil, mixed oil, or soybean oil-based lipid emulsions have differential effects on the regulation of lipogenic and lipolytic genes in mature 3T3-L1 adipocytes

The key adipose tissue characteristics are established during early development, where lipids play an essential role. Lipid emulsions used in total parenteral nutrition have different omega-(n) 6 to n-3 fatty acid ratios. A lower n-6:n-3 fatty acid decreases lipid accumulation; however, the effects of lipid emulsions with different n-6 to n-3 fatty acid ratios on the programming of preadipocytes to affect lipid accumulation in mature adipocytes is not known. This study compared the effects of Fish oil (FO), Mixed oil (MO), and Soybean oil (SO) based lipid emulsion on genes involved in adipogenesis, lipogenesis, lipolysis, and β-oxidation in 3T3-L1 adipocytes. Preadipocytes were treated with specific lipid emulsions and then differentiated to mature adipocytes in the absence of lipid emulsions. In a separate experiment, mature 3T3-L1 adipocytes were treated with lipid emulsions to investigate the effects on genes involved in lipolysis. Fatty acid composition, triacylglycerol levels, and the mRNA expression of genes involved in adipogenesis, lipogenesis, lipolysis, and β-oxidation were measured. Preadipocytes and mature adipocytes treated with FO showed higher incorporation of n-3 polyunsaturated fatty acids, lower triacylglycerol levels, and decreased mRNA expression of adipogenic and lipogenic genes, followed by MO and SO. FO and MO increased the mRNA expression of carnitine palmitoyltransferase-1, while FO decreased the mRNA expression of lipolytic genes compared to untreated cells. Our findings suggest that FO programs preadipocytes to prevent adipose tissue dysfunction in mature adipocytes; the effects of FO-based lipid emulsion were followed by MO and SO.

Unexpected Antioxidant Efficiency of Chlorogenic Acid Phenolipids in Fish Oil-in-Water Nanoemulsions: An Example of How Relatively Low Interfacial Concentrations Can Make Antioxidants to Be Inefficient

Selecting effective antioxidants is challenging since their efficiency in inhibiting lipid oxidation depends on the rate constants of the chemical reactions involved and their concentration at the reaction site, i.e., at the interfacial region. Accumulation of antioxidants at the interface of emulsions is key to modulate their efficiency in inhibiting lipid oxidation but its control was not well understood, especially in emulsions. It can be optimized by modifying the physicochemical properties of antioxidants or the environmental conditions. In this work, we analyze the effects of surfactant concentration, droplet size, and oil to water ratio on the effective interfacial concentration of a set of chlorogenic acid (CGA) esters in fish oil-in-water (O/W) emulsions and nanoemulsions and on their antioxidant efficiency. A well-established pseudophase kinetic model is used to determine in the intact emulsified systems the effective concentrations of the antioxidants (AOs). The relative oxidative stability of the emulsions is assessed by monitoring the formation of primary oxidation products with time. Results show that the concentration of all AOs at the interfacial region is much higher (20–90 fold) than the stoichiometric one but is much lower than those of other phenolipid series such as caffeic or hydroxytyrosol derivatives. The main parameter controlling the interfacial concentration of antioxidants is the surfactant volume fraction, Φ_I, followed by the O/W ratio. Changes in the droplet sizes (emulsions and nanoemulsions) have no influence on the interfacial concentrations. Despite the high radical scavenging capacity of CGA derivatives and their being concentrated at the interfacial region, the investigated AOs do not show a significant effect in inhibiting lipid oxidation in contrast with what is observed using other series of homologous antioxidants with similar reactivity. Results are tentatively interpreted in terms of the relatively low interfacial concentrations of the antioxidants, which may not be high enough to make the rate of the inhibition reaction faster than the rate of radical propagation.

NF-κB Regulation of LRH-1 and ABCG5/8 Potentiates Phytosterol Role in the Pathogenesis of Parenteral Nutrition-Associated Cholestasis

BACKGROUND AND AIMS

Chronically administered parenteral nutrition (PN) in patients with intestinal failure carries the risk for developing PN-associated cholestasis (PNAC). We have demonstrated that farnesoid X receptor (FXR) and liver X receptor (LXR), proinflammatory interleukin-1 beta (IL-1β), and infused phytosterols are important in murine PNAC pathogenesis. In this study we examined the role of nuclear receptor liver receptor homolog 1 (LRH-1) and phytosterols in PNAC.

APPROACH AND RESULTS

In a C57BL/6 PNAC mouse model (dextran sulfate sodium [DSS] pretreatment followed by 14 days of PN; DSS-PN), hepatic nuclear receptor subfamily 5, group A, member 2/LRH-1 mRNA, LRH-1 protein expression, and binding of LRH-1 at the Abcg5/8 and Cyp7a1 promoter was reduced. Interleukin-1 receptor-deficient mice (Il-1r^-/- /DSS-PN) were protected from PNAC and had significantly increased hepatic mRNA and protein expression of LRH-1. NF-κB activation and binding to the LRH-1 promoter were increased in DSS-PN PNAC mice and normalized in Il-1r^-/- /DSS-PN mice. Knockdown of NF-κB in IL-1β-exposed HepG2 cells increased expression of LRH-1 and ABCG5. Treatment of HepG2 cells and primary mouse hepatocytes with an LRH-1 inverse agonist, ML179, significantly reduced mRNA expression of FXR targets ATP binding cassette subfamily C member 2/multidrug resistance associated protein 2 (ABCC2/MRP2), nuclear receptor subfamily 0, groupB, member 2/small heterodimer partner (NR0B2/SHP), and ATP binding cassette subfamily B member 11/bile salt export pump (ABCB11/BSEP). Co-incubation with phytosterols further reduced expression of these genes. Similar results were obtained by suppressing the LRH-1 targets ABCG5/8 by treatment with small interfering RNA, IL-1β, or LXR antagonist GSK2033. Liquid chromatography-mass spectrometry and chromatin immunoprecipitation experiments in HepG2 cells showed that ATP binding cassette subfamily G member 5/8 (ABCG5/8) suppression by GSK2033 increased the accumulation of phytosterols and reduced binding of FXR to the SHP promoter. Finally, treatment with LRH-1 agonist, dilauroyl phosphatidylcholine (DLPC) protected DSS-PN mice from PNAC.

CONCLUSIONS

This study suggests that NF-κB regulation of LRH-1 and downstream genes may affect phytosterol-mediated antagonism of FXR signaling in the pathogenesis of PNAC. LRH-1 could be a potential therapeutic target for PNAC.

A Mixed-Lipid Emulsion Containing Fish Oil for the Parenteral Nutrition of Preterm Infants: No Impact on Visual Neuronal Conduction

Fish oil is rich in omega-3 fatty acids and essential for neuronal myelination and maturation. The aim of this study was to investigate whether the use of a mixed-lipid emulsion composed of soybean oil, medium-chain triglycerides, olive oil, and fish oil (SMOF-LE) compared to a pure soybean oil-based lipid emulsion (S-LE) for parenteral nutrition had an impact on neuronal conduction in preterm infants. This study is a retrospective matched cohort study comparing preterm infants <1000 g who received SMOF-LE in comparison to S-LE for parenteral nutrition. Visual evoked potentials (VEPs) were assessed longitudinally from birth until discharge. The latencies of the evoked peaks N2 and P2 were analyzed. The analysis included 76 infants (SMOF-LE: n = 41 and S-LE: n = 35) with 344 VEP measurements (SMOF-LE: n= 191 and S-LE n = 153). Values of N2 and P2 were not significantly different between the SMOF-LE and S-LE groups. A possible better treatment effect in the SMOF-LE group was seen as a trend toward a shorter latency, indicating faster neural conduction at around term-equivalent age. Prospective trials and follow-up studies are necessary in order to evaluate the potential positive effect of SMOF-LE on neuronal conduction and visual pathway maturation.

Lipid-Free PN is Associated with an Increased Risk of Hyperbilirubinemia in Surgical Critically Ill Patients with Admission Hepatic Disorder: A Retrospective Observational Study

Background

To evaluate the effect of different PN types on surgical critically ill trauma/acute care surgery patients with hepatic disorders at admission.

Methods

This is a retrospective study. The PN types included lipid-free, soybean oil/medium-chain triglyceride, olive oil-based, and fish oil-containing PNs. Patients admitted with liver injury or liver surgery, elevated serum AST/ALT level, and elevated serum total bilirubin level were included. The exclusion criteria are as follows: 1) age <18 years, 2) severe liver disease/cirrhosis, 3) received more than one type of PN and 4) serum total bilirubin >4.9 mg/dl at admission. Demographics, severity, comorbidities, blood stream infection, hyperbilirubinemia (total bilirubin > 6.0 mg/dl), and mortality were collected for analysis. We also performed analysis stratified by separated lipid doses (g/kg/day).

Results

A total of 156 patients were enrolled. There were no demographic differences among groups. The lipid-free group was associated with the highest mortality rate and incidence of hyperbilirubinemia. Compared to the lipid-free group, the olive oil-based group had the lowest risk of hyperbilirubinemia. After being stratified by separated lipid doses, the incidence of hyperbilirubinemia decreased when the lipid dosage increased. Regarding different types of lipids, patients who received more than the median dosage of lipids showed a significantly lower risk of hyperbilirubinemia, except in the fish oil-containing group.

Conclusion

Our result suggested that lipid-free PN is associated with an increased risk of hyperbilirubinemia in surgical critically ill patients with admission hepatic disorder. Further studies are warranted.

Lipid-Free Parenteral Nutrition Is Associated with an Increased Risk of Hepatic Dysfunction in Surgical Critically Ill Patients: A Retrospective Observational Study

To evaluate the effects of lipid-free parenteral nutrition (PN) and various intravenous fat emulsions (IVFEs) on hepatic function in surgical critically ill trauma/acute care surgery patients. We retrospectively reviewed trauma/acute care surgery patients without admission hepatic disorder that received PN. The PN groups include lipid-free, soybean oil/medium-chain triglyceride, olive oil-based, and fish-oil contained PN. We excluded patients with (1) age <18 years, (2) without surgery, (3) preexisting liver injury/diseases, (4) hyperbilirubinemia at admission, (5) received more than one type of PN, and (6) repeated ICU episodes in the same hospitalization. Hepatic dysfunction was considered as serum total–bilirubin >6.0 mg/dL. The demographics, severity score, comorbidities, blood stream infection, and mortality were collected for analyses. The major outcome is hepatic function. We also performed analyses stratified by separated lipid doses (g/kg/day). A total of 249 patients were enrolled. There were no demographic differences among groups. The lipid-free PN group had a higher incidence of hepatic dysfunction and mortality. Compared to the lipid-free group, the other three IVFEs had significantly lower risks of hepatic dysfunction, while the olive oil-based group had a significantly lower risk of 30 and 90-day mortality. After being stratified by separating lipid doses, the soybean oils showed a decreasing trend of hepatic dysfunction and mortality with increased dosage. Fish oil >0.05 g/kg/day was associated with lower hepatic dysfunction incidences. Our findings suggest that, when compared to IVFEs, surgical critically ill patients with trauma/acute care surgery that received lipid-free PN are associated with an increased risk of hepatic dysfunction. In addition, the olive oil-based group had a significantly lower risk of mortality, while fish oil >0.05 g/kg/day was associated with lower incidences of hepatic dysfunction; however, further studies are warranted.

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.

REVIEW: Practical strategies to maintain anabolism by intravenous nutritional management in children with inborn metabolic diseases

One of the most vital elements of management for patients with inborn errors of intermediary metabolism is the promotion of anabolism, the state in which the body builds new components, and avoidance of catabolism, the state in which the body breaks down its own stores for energy. Anabolism is maintained through the provision of a sufficient supply of substrates for energy, as well as critical building blocks of essential amino acids, essential fatty acids, and vitamins for synthetic function and growth. Patients with metabolic diseases are at risk for decompensation during prolonged fasting, which often occurs during illnesses in which enteral intake is compromised. During these times, intravenous nutrition must be supplied to fully meet the specific nutritional needs of the patient. We detail our approach to intravenous management for metabolic patients and its underlying rationale. This generally entails a combination of intravenous glucose and lipid as well as early introduction of protein and essential vitamins. We exemplify the utility of our approach in case studies, as well as scenarios and specific disorders which require a more careful administration of nutritional substrates or a modification of macronutrient ratios.

Interfacial kinetics in olive oil-in-water nanoemulsions: Relationships between rates of initiation of lipid peroxidation, induction times and effective interfacial antioxidant concentrations

HYPOTHESIS

A detailed quantitative description of the effects of antioxidants in inhibiting lipid peroxidation in oil-in-water emulsions can be achieved by determining the relationships between the rates of initiation of the lipid peroxidation reaction, the length of the induction period preceding the propagation step of the radical oxidation process and the effective antioxidant interfacial concentrations.

EXPERIMENTS

We successfully prepared and characterized a series of olive oil-in-water nanoemulsions and allowed them to spontaneously oxidize. Their oxidative stability was evaluated by carrying out in the presence, and absence, of antioxidants derived from gallic acid, by monitoring the formation of primary oxidation products with time, by determining the corresponding induction periods, and by determining the effective interfacial concentrations of the antioxidants in the intact emulsions.

FINDINGS

Results show that both, the length of the induction periods and the antioxidant interfacial concentrations change concomitantly, increasing with the hydrophobicity of the antioxidant up to a maximum at the octyl derivative; longer aliphatic chains decrease their efficiency. The ratio between the interfacial antioxidant concentration and the induction period remains constant independently of the antioxidant, demonstrating that the effective concentrations of antioxidant at the interface control their efficiencies in emulsions.

An Intravenous 100-mL Lipid Emulsion Infusion Dramatically Improves Myocardial Glucose Metabolism Extinction in Cardiac FDG PET Clinical Practice

PURPOSE

Physiological myocardial accumulation of FDG impairs the diagnosis of inflammatory/infectious or tumoral myocardial detection by FDG PET/CT. We prospectively evaluated the addition, 3 hours before imaging, of an intravenous 100-mL lipid emulsion infusion (Intralipid) to a high-fat, low-carbohydrate diet (HFLCD) for at least 2 meals followed by a fast of at least 6 to 12 hours in patients referred for the diagnosis of myocardial inflammation, endocarditis, cardiac or paracardiac masses, intracardiac device, or prosthetic valve infections.

METHODS

Data of 58 patients consecutively included (28 Intralipid patients, 30 controls with HFLCD alone) were compared. FDG uptake in normal myocardium was scored from 0 (complete myocardial suppression) to 3 (high diffuse uptake). Myocardial maximal, peak, and mean SUV and the rate of interpretable images according to the clinical indication were measured.

RESULTS

Compared with controls, Intralipid infusion significantly improved the rate of score 0 (89% vs 63%, P = 0.021), of interpretable images according to the clinical indication (100% vs 72%, P = 0.0047) and decreased all myocardial SUV values (eg, SUVmax median, 1.9 [interquartile range, 1.7-2.5] vs 3.1 [interquartile range, 2.3-4.1]; P < 0.001).

CONCLUSIONS

A lipid emulsion infusion in addition to HFLCD better suppresses cardiac glucose metabolism than HFLCD alone.

A four-oil intravenous lipid emulsion improves markers of liver function, triglyceride levels and shortens length of hospital stay in adults: a systematic review and meta-analysis

Clinical trials have reported that a four-oil intravenous lipid emulsion (SMOFlipid) play a positive role in immune function, but showed inconsistent outcomes compared to other lipid emulsions. A systematic review and meta-analysis was conducted to evaluate the effect of SMOFlipid on liver function, triglycerides (TG), inflammatory markers, and clinical outcomes in hospitalized adults after short-term use compared to others. A search of the PubMed, Medline, Embase, China National Knowledge Infrastructure, and Wanfang databases was performed to identify the included randomized controlled trials. Trials with adults who were administrated a short-term course of SMOFlipid were included. A meta-analysis on liver function markers, TG, inflammatory markers, and clinical outcomes was conducted. A total of 18 randomized controlled trials with 1188 patients were included. Compared to other lipid emulsions, SMOFlipid was associated with a significant reduction in ALT, AST, γ-glutamyltransferase, total bilirubin, TG, C-reactive protein and length of hospital stay. No effect on serum interleukin-6 levels or adverse events were observed. For adult patients, our meta-analysis indicated that SMOFlipid may be beneficial to the liver and prone to prevent hyperlipidemia. The SMOFlipid also shortened length of hospital stay.

Preparation and Evaluation of Lipid Emulsion Containing 13 Vitamins for Injection Without Anaphylactoid Reactions

Objective

Multivitamins containing Tween 80 can cause anaphylactoid reactions. The objective of this study was to develop a new lipid emulsion containing 13 fat- and water-soluble vitamins for injection (13V-LE) that were simultaneously dissolved in one bottle and to evaluate the stability of and anaphylactoid reactions to 13V-LE.

Methods

Particle size, ζ-potential, and polydispersity of 13V-LE were assayed with a Zetasizer Nano ZS. Entrapment efficiency of 13V-LE was determined with HPLC. Behavior, histamine, and blood pressure of beagle dogs were investigated by observation, fluorospectrophotometry, and sphygmomanometry.

Results

The 13V-LE with the smallest particles and highest entrapment efficiency with stable ζ-potential was composed of soybean oil, glycerin (2.25%, w:v), egg lecithin (1.2%, w:v), and purified water. There was no obvious change in characteristics of the 13V-LE samples in terms of appearance, size distribution, ζ-potential, pH value, or concentration over 6 months. In anaphylactoid reactions tests, when being administered with the multivitamin Infuvite Adult containing Tween 80, six beagles showed grade IV symptoms (P<0.01 vs control), low blood pressure, and high plasma-histamine concentrations (P<0.05 or P<0.01). However, there were no significant differences in behavior, blood pressure, or histamine concentration in the dogs before and after administration in the 13V-LE group.

Conclusion

The 13V-LE formulation is a suitable intravenous lipid emulsion without anaphylactoid reactions.

Polyphenolic Antioxidants in Lipid Emulsions: Partitioning Effects and Interfacial Phenomena

The autoxidation of lipids in complex systems such as emulsions or biological membranes, although known to occur readily and to be associated with important pathological events, is lacking in quantitative data in spite of the huge efforts that have been made in attempting to unravel the complex mechanisms of lipid oxidation and its inhibition by antioxidants. Lipids are present as oil-in-water emulsions in many foods and pharmaceutical formulations, and the prevalent role of the interfacial region is critical to understand the antioxidant behavior and to correctly interpret antioxidant efficiencies. The aim of this review is to summarize the current knowledge on the chemical fate of antioxidants before they react with peroxyl radicals. Many researchers highlighted the predominant role of interfaces, and although some attempts have been made to understand their role, in most instances, they were essentially qualitative and based on putative hypotheses. It is only recently that quantitative reports have been published. Indeed, knowledge on the effects of relevant experimental variables on the effective concentrations of antioxidants is necessary for a successful design of alternate, effective antioxidative solutions.

Lipids in Parenteral Nutrition: Biological Aspects

Lipid emulsions are an integral part of parenteral nutrition, and traditionally have been regarded as an energy-dense source of calories and essential fatty acids. For many years, lipids used in parenteral nutrition have been based on vegetable oils (eg, soybean-oil emulsions). However, soybean-oil emulsions may not have an optimal fatty-acid composition under some circumstances when used as the only lipid source, as soybean oil is particularly abundant in the ω-6 polyunsaturated fatty acid (PUFA), linoleic acid. Hence, a progressive series of more complex lipid emulsions have been introduced, typically combining soybean oil with 1 or more alternative oils, such as medium-chain triglycerides (MCTs) and/or olive oil and/or fish oil. The wide range of lipid emulsions now available for parenteral nutrition offers opportunities to alter the supply of different fatty acids, which potentially modifies functional properties, with effects on inflammatory processes, immune response, and hepatic metabolism. Fish oil has become an important component of modern, composite lipid emulsions, in part owing to a growing evidence base concerning its biological effects in a variety of preclinical models. These biological activities of fish oil are mainly attributed to its ω-3 PUFA content, particularly docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). DHA and EPA have known mechanisms of action, anti-inflammatory, immunomodulatory, and antioxidative properties. Specialized proresolving mediators, such as resolvins, protectins, and maresins, are synthesized directly from DHA and EPA, are key for the resolution of inflammation, and improve outcomes in many cell- and animal-based models and, recently, in some clinical settings.

Summary of Proceedings and Expert Consensus Statements From the International Summit "Lipids in Parenteral Nutrition"

BACKGROUND

The 2018 Lipids in Parenteral Nutrition summit involved a panel of experts in clinical nutrition, lipid metabolism, and pharmacology, to assess the current state of knowledge and develop expert consensus statements regarding the use of intravenous lipid emulsions in various patient populations and clinical settings. The main purpose of the consensus statements is to assist healthcare professionals by providing practical guidance on common clinical questions related to the provision of lipid emulsions as part of parenteral nutrition (PN).

METHODS

The summit was designed to allow interactive discussion and consensus development. The resulting consensus statements represent the collective opinion of the members of the expert panel, which was informed and supported by scientific evidence and clinical experience.

RESULTS

The current article summarizes the key discussion topics from the summit and provides a set of consensus statements designed to complement existing evidence-based guidelines. Lipid emulsions are a major component of PN, serving as a condensed source of energy and essential fatty acids. In addition, lipids modulate a variety of biologic functions, including inflammatory and immune responses, coagulation, and cell signaling. A growing body of evidence suggests that lipid emulsions containing ω-3 fatty acids from fish oil confer important clinical benefits via suppression of inflammatory mediators and activation of pathways involved in the resolution of inflammation.

CONCLUSIONS

This article provides a set of expert consensus statements to complement formal PN guideline recommendations.

Lipid Use in Hospitalized Adults Requiring Parenteral Nutrition

In hospitalized patients, lipid emulsions are an integral part of balanced parenteral nutrition. Traditionally, a single lipid source, soybean oil, has been given to patients and was usually regarded as just a source of energy and to prevent essential fatty-acid deficiency. However, mixtures of different lipid emulsions have now become widely available, including mixtures of soybean oil, medium-chain triglycerides, olive oil, and fish oil. Fish oil is high in the ω-3 polyunsaturated fatty acids docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). There is a growing body of evidence that these ω-3 fatty acids can exert beneficial immunomodulatory, anti-inflammatory, and inflammation-resolution effects across a wide range of patient groups including surgical, cancer, and critically ill patients. At least in part, these effects are realized via potent specialized pro-resolution mediators (SPMs). Moreover, parenteral nutrition including ω-3 fatty acids can result in additional clinical benefits over the use of standard lipid emulsions, such as reductions in infection rates and length of hospital and intensive care unit stay. Clinical and experimental evidence is reviewed regarding lipid emulsion use in a variety of hospitalized patient groups, including surgical, critically ill, sepsis, trauma, and acute pancreatitis patients. Practical aspects of lipid emulsion use in critically ill patients are also considered, such as how to determine and fulfill energy expenditure, how and when to consider parenteral nutrition, duration of infusion, and safety monitoring.

Carotid artery intima-media thickness in adults receiving long-term home parenteral nutrition

BACKGROUND AND AIMS

Nutrition regimen in parenteral nutrition (PN) patients allows for a control of diet components. This may affect the process of lipid deposition in the vascular wall and change the risk of atherosclerosis. This study aims to examine the effect of long-term PN in adults on carotid intima-media thickness.

METHODS AND RESULTS

Thirty long-term PN patients (15 men and 15 women, mean age 64.7 ± 8.5 years) and thirty healthy volunteers (HV) (15 men and 15 women, mean age 64.9 ± 8.77 years) entered the study. Total amino acid and lipid formulation intake as well as duration of PN were calculated for PN patients. The common carotid artery intima-media thickness (CCA IMT) was examined in both groups. A lower CCA IMT (right/left mean: PN - 776 ± 121 vs HV - 848 ± 121 μm, p < 0.05; right/left maximum CCA IMT: PN - 935 ± 139 vs HV - 1024 ± 135 μm, p < 0.05) in PN patients was observed. A lower serum level of total (PN - 131.43 ± 43.12 vs HV - 209.2 ± 48.01 mg/dl, p < 0.05) and HDL (PN- 44.16 ± 12.45 vs HV - 72.57 ± 25.04 mg/dl, p < 0.05) cholesterol was reported in the PN patients. A correlation between patients' age and CCA IMT was observed in the control group, but not in the PN patients (right/left mean CCA IMT - PN: r = 0.48, p-0.007 vs HV: p-0.073; right/left maximum CCA IMT - PN: r = 0.48, p-0.008, vs HV: p-0.073).

CONCLUSIONS

Long term PN in adults is associated with lower CCA IMT. Long-term PN patients are a unique group in which carotid intima-media thickness does not correlate with the age.

Does the use of fish oil-based lipid emulsion in the clinical setting of total parenteral nutrition and lipid rescue therapy interfere with common laboratory analytes on Roche Cobas 6000?

BACKGROUND

Lipaemic interference on automated analysers has been widely studied using soy-based emulsion such as Intralipid. Due to the greater adoption of fish oil-based lipid emulsion for total parenteral nutrition in view of improved clinical outcomes, we seek to characterize the optical properties of SMOFlipid 20% (Fresenius Kabi, Bad Homburg, Germany), a fish oil-based emulsion, on the Roche Cobas 6000 chemistry analyser (Roche Diagnostic, Basel, Switzerland).

METHOD

Various amounts of SMOFlipid were spiked into pooled serums. We plotted Roche Cobas Serum Index Gen.2 Lipaemia Index (L-index) against the amount of SMOFlipid added. We then studied the interference thresholds for aspartate aminotransferase, alanine aminotransferase, albumin and renal panel analytes using SMOFlipid. We subjected five levels of spiked lipaemia to high-speed centrifugation and analysed the specimens pre- and post-centrifugation. To postulate whether fish oil-based lipid emulsion interferes with laboratory results in the clinical setting, we calculated concentrations of SMOFlipid post-lipid rescue therapy and steady-state concentration of a typical total parenteral nutrition regime using pharmacokinetic principles.

RESULTS

SMOFlipid optical behaviour is similar to Intralipid using the Serum Index Gen.2 L-index, with 1 mg/dL of SMOFlipid representing 1 unit of L-index. Manufacturer-stated interference thresholds are accurate for alanine aminotransferase, aspartate aminotransferase, albumin, urea and creatinine. High-speed centrifugation at 60 min 21,100g facilitates the removal of fish oil-based SMOFlipid.

CONCLUSION

Based on the interference thresholds we verified and pharmacokinetics parameters provided by SMOFlipid manufacturer, total parenteral nutrition may not interfere with chemistry analytes given sufficient clearance, but lipid rescue therapy will interfere. Further studies assessing lipaemic interference on immunoassays are needed.

Hydrogen sulfide guards myoblasts from ferroptosis by inhibiting ALOX12 acetylation

Recognized as a novel and important gasotransmitter, hydrogen sulfide (H₂S) is widely present in various tissues and organs. Cystathionine gamma-lyase (CSE)-derived H₂S has been shown to regulate oxidative stress and lipid metabolism. The aim of the present study is to examine the role of H₂S in ferroptosis and lipid peroxidation in mouse myoblasts and skeletal muscles. Ferroptosis agonist RSL3 inhibited the expressions of Gpx4 and reduced CSE/H₂S signaling, which lead to increased oxidative stress, lipid peroxidation, and ferroptotic cell death. In addition, ferroptosis antagonist ferrostatin-1 (Fer-1) up-regulated the expression of CSE, scavenged the generation of reactive oxygen species (ROS) and lipid peroxidation, and improved cell viability. Exogenously applied NaHS was also able to block RSL3-induced ferroptotic cell death. Neither RSL3 nor H₂S affected cell apoptosis. Furthermore, H₂S reversed RSL3-induced Drp1 expression and mitochondrial damage, which lead to abnormal lipid metabolism as evidenced by altered expressions of ACSL4, FAS, ACC and CPT1 as well as higher acetyl-CoA contents in both cytoplasm and mitochondria. RSL3 promoted the protein expression and acetylation of ALOX12, a key protein in initiating membrane phospholipid oxidation, while the addition of NaHS attenuated ALOX12 acetylation and protected from membrane lipid peroxidation. Moreover, we observed that CSE deficiency alters the expressions of ferroptosis and lipid peroxidation-related proteins and enhances global protein acetylation in mouse skeletal muscles under aging or injury conditions. These results indicate that downregulation of CSE/H₂S signaling would contribute to mitochondrial damage, abnormal lipid metabolism, membrane lipid peroxidation, and ferroptotic cell death. CSE/H₂S system can be a target for preventing ferroptosis in skeletal muscle.

Clinical application of fish-oil intravenous lipid emulsion in adult home parenteral nutrition patients

BACKGROUND

High-ω-6 polyunsaturated fatty acids (PUFAs) are noted to contribute to development of intestinal failure-associated liver disease (IFALD) in home parenteral nutrition (HPN). Fish oil (FO) has been added to latest generation of lipid injectable emulsion (ILE) to increase ω-3:ω-6 PUFA ratio; however, appropriate dose of FO to treat IFALD is unknown.

METHODS

After approval of exclusive FO ILE in the US for pediatric patients, we noted 2 adult patients with ongoing IFALD despite transition to mixed-oil (MO) ILE. They were transitioned to off-label FO ILE after review of literature regarding use of FO ILE in adult HPN patients was conducted to guide management.

RESULTS

The first case involves a 40-year-old female receiving HPN with IFALD refractory to MO ILE. MO ILE (with 15% FO) was provided at 50 g/d for 3 d/wk and combined with FO ILE at 50 g/d for 4 d/wk. This combination resulted in improvement in liver studies and allowed for decrease in dextrose calories. The second case involves a 49-year-old male receiving HPN (secondary to complications of necrotizing pancreatitis) who developed IFALD. FO ILE was used as the sole source of lipids and led to improvement in liver function tests. No evidence of essential fatty acid deficiency was found in either case.

CONCLUSIONS

Current case presentations and review of literature support the use of FO ILE to increase ω-3 PUFAs in patients with IFALD refractory to MO ILE. Additional research is necessary to delineate the dose of FO ILE necessary to achieve benefit.

COVID-19 and immunomodulation treatment for women with reproductive failures

COVID-19 pandemic is affecting various areas of health care, including human reproduction. Many women with reproductive failures, during the peri-implantation period and pregnancy, are on the immunotherapy using immune modulators and immunosuppressant due to underlying autoimmune diseases, cellular immune dysfunction, and rheumatic conditions. Many questions have been raised for women with immunotherapy during the COVID-19 pandemic, including infection susceptibility, how to manage women with an increased risk of and active COVID-19 infection. SARS-CoV-2 is a novel virus, and not enough information exists. Yet, we aim to review the data from previous coronavirus outbreaks and current COVID-19 and provide interim guidelines for immunotherapy in women with reproductive failures.

Blood clearance kinetics and organ delivery of medium-chain triglyceride and fish oil-containing lipid emulsions: Comparing different animal species

BACKGROUND & AIMS

Medium-chain triglycerides (TG) (MCT) and fish oil (FO) TG are incorporated as the core TG component into intravenous (IV) lipid emulsions for infusion in parenteral nutrition. Bolus injections of IV emulsions, on the other hand, have emerged as a novel therapeutic approach to treat various acute disorders. However, intravascular metabolism and organ delivery of acute IV injection of emulsions containing both MCT and FO are not fully defined, nor have they been characterized across common experimental animal models. We characterized and compared blood clearance kinetics and organ distribution of bolus injections of MCT/FO emulsions among different animal species. We also examined whether sex differences or feeding status can affect catabolic properties of MCT/FO lipid emulsions.

DESIGN

Blood clearance rates of lipid emulsions with specific TG composition were compared in rats IV injected with [3H]cholesteryl hexadecyl ether labeled pure n-6 long-chain (LCT) and n-3 FO TG lipid emulsions, or emulsions containing MCT and FO at different ratios (wt/wt), which include 8:2 (80% MCT: 20% FO), 5:4:1 (50% MCT: 40% LCT: 10% FO) and SMOF (30% LCT: 30% MCT: 25% olive oil: 10% FO). Dose-response effects (0.016 mg-1.6 mg TG/g body weight) of the MCT/FO 8:2 emulsions on blood clearance properties and organ delivery were determined in both mice and rats. Blood clearance kinetics and organ uptake of MCT/FO 8:2 emulsions were compared between male and female rats and between fed and fasted rats. Changes in plasma lipid profiles after acute injections of MCT/FO 8:2 lipid emulsion at different doses (0.043, 0.133, and 0.4 mg TG/g body weight) were characterized in non-human primates (Cynomolgus monkeys).

RESULTS

MCT/FO 8:2 emulsion was cleared faster in rats when compared with other emulsions with different TG contents. Mice had faster blood clearance and higher fractional catabolic rates (FCR) when compared with the rats injected with MCT/FO 8:2 emulsions regardless of the injected doses. Mice and rats had similar plasma TG and free fatty acid (FFA) levels after low- or high-dose injections of the MCT/FO emulsion. Tissue distribution of the MCT/FO 8:2 lipid emulsion are comparable between mice and rats, where liver had the highest uptake per recovered dose among all organs (>60%). Feeding status and sex differences did not alter the blood clearance rate of the MCT/FO 8:2 emulsion in rats. In a nonhuman primate model, dose-response increases in plasma TG and FFA were observed after IV injection of MCT/FO 8:2 emulsions within the 1st 10 min.

CONCLUSION

A lipid emulsion containing both MCT and FO TG is cleared rapidly in blood and readily available for organ uptake in rodent and primate animal models. Characterization of the blood clearance properties of the MCT/FO 8:2 emulsion administered in various animal models may provide further insight into the safety and efficacy profiles for future therapeutic use of bolus injections of MCT/FO emulsions in humans.

Altered nutrient status reprograms host inflammation and metabolic health via gut microbiota

The metabolism of macro- and micronutrients is a complex and highly regulated biological process. An imbalance in the metabolites and their signaling networks can lead to nonresolving inflammation and consequently to the development of chronic inflammatory-associated diseases. Therefore, identifying the accumulated metabolites and altered pathways during inflammatory disorders would not only serve as "real-time" markers but also help in the development of nutritional therapeutics. In this review, we explore recent research that has delved into elucidating the effects of carbohydrate/calorie restriction, protein malnutrition, lipid emulsions and micronutrient deficiencies on metabolic health and inflammation. Moreover, we describe the integrated stress response in terms of amino acid starvation and lipemia and how this modulates new age diseases such as inflammatory bowel disease and atherosclerosis. Lastly, we explain the latest research on metaflammation and inflammaging. This review focuses on multiple signaling pathways, including, but not limited to, the FGF21-β-hydroxybutryate-NLRP3 axis, the GCN2-eIF2α-ATF4 pathway, the von Hippel-Lindau/hypoxia-inducible transcription factor pathway and the TMAO-PERK-FoxO1 axis. Additionally, throughout the review, we explain how the gut microbiota responds to altered nutrient status and also how antimicrobial peptides generated from nutrient-based signaling pathways can modulate the gut microbiota. Collectively, it must be emphasized that metabolic starvation and inflammation are strongly regulated by both environmental (i.e., nutrition, gut microbiome) and nonenvironmental (i.e., genetics) factors, which can influence the susceptibility to inflammatory disorders.

Evaluation of SMOFlipid in Pediatric Intestinal-Failure Patients and Its Effects on Essential Fatty Acid Levels

BACKGROUND

SMOFlipid is a mixed-lipid emulsion approved for adults in the United States as an alternative to soybean oil-based lipid (SO). There are limited data on the use of SMOFlipid in pediatrics and its effect on the fatty acid (FA) profile. Our objective was to characterize changes in FA profile, liver function, and growth in pediatric patients with intestinal failure (IF), following transition from SO or a fish-oil (FO) and SO combination to SMOFlipid.

METHODS

A retrospective case series was conducted on pediatric parenteral nutrition-dependent IF patients transitioned to SMOFlipid. Demographics, anthropometrics, labs, and achievement of nutrition goals were assessed. Linear mixed-effect models assessed effects on FA levels and clinical outcomes.

RESULTS

One hundred thirty-nine FA panels were collected from 20 patients. Median SMOFlipid dose at study completion was 2 g/kg/d (interquartile range, 1.6-2). During the 1.5 years after SMOFlipid initiation, ω-6 FA increased to physiologic levels, arachidonic acid increased from 298 to 461 nmol/mL (P < .001), and linoleic acid increased from 1172 to 1922 nmol/mL (P < .001). ω-3 FA remained within normal limits. Body mass index z-score and length z-score increased, though no significant changes were found. In addition, no significant changes were found in mead acid, hepatic function, triene-to-tetraene ratio, or triglycerides.

CONCLUSION

In 20 pediatric IF patients, SMOFlipid allowed greater ω-6 FA provision while maintaining ω-3 FA, hepatic function, and patient growth. This longitudinal study identified improved FA profile associated with SMOFlipid use in comparison with SO with or without FO.

Current status of lipid emulsions in the prevention of intestinal failure-associated liver disease

PURPOSE OF REVIEW

The current review provides a summary of available lipid products and discusses current literature and the limitations to the use of various lipid products for treatment and prevention of intestinal failure-associated liver disease (IFALD) in pediatric patients dependent on parenteral nutrition.

RECENT FINDINGS

Improvements in markers of cholestasis and liver function have been seen with minimizing soybean lipid, fish oil lipid, and mixed fish oil-containing lipid emulsions. Soybean-based lipid products are thought to be the biggest contributor to development of IFALD. Mixed fish oil-containing lipid emulsions are most promising for minimizing and improving IFALD.

SUMMARY

Several types of lipid-based products are available for parenteral nutrition. Newer products like the mixed fish oil-containing-based lipid emulsions, that closely mimic the lipid composition provided by enteral feeding, may impact prevention and treatment of IFALD. Limitations exist in the current literature regarding mixed fish oil-containing-based emulsions, as many of the studies were designed to show efficacy with regard to growth, not prevention or treatment of IFALD. Based on available literature, it is reasonable to make some recommendations with regard to product selection for lipid provision.

Impacts of Intralipid on Nanodrug Abraxane Therapy and on the Innate Immune System

A major obstacle to nanodrugs-mediated cancer therapy is their rapid uptake by the reticuloendothelial system that decreases the systemic exposure of the nanodrugs to tumors and also increases toxicities. Intralipid has been shown to reduce nano-oxaliplatin-mediated toxicity while improving bioavailability. Here, we have found that Intralipid reduces the cytotoxicity of paclitaxel for human monocytic cells, but not for breast, lung, or pancreatic cancer cells. Intralipid also promotes the polarization of macrophages to the anti-cancer M1-like phenotype. Using a xenograft breast cancer mouse model, we have found that Intralipid pre-treatment significantly increases the amount of paclitaxel reaching the tumor and promotes tumor apoptosis. The combination of Intralipid with half the standard clinical dose of Abraxane reduces the tumor growth rate as effectively as the standard clinical dose. Our findings suggest that pre-treatment of Intralipid has the potential to be a powerful agent to enhance the tumor cytotoxic effects of Abraxane and to reduce its off-target toxicities.

Microbial Contamination of Neonatal Injectable Lipid Emulsions at 12 and 24 Hours' Infusion Time With Evaluation of Infection Control Measures

OBJECTIVES

This study aimed to assess the microbial contamination rate of injectable lipid emulsion (ILE) repackaged syringes at 12 and 24 hours of their infusion time. Probable risk factors associated with contamination of the ILEs were also assessed. In addition, the antimicrobial resistance pattern of the bacterial isolates was also determined.

METHODS

Samples of ILE were collected from 152 repackaged syringes and their infusion lines after 12 hours and 24 hours of infusion time (73 and 79 samples, respectively). Samples were cultured, the isolates were identified, and the antimicrobial resistance pattern of the bacterial isolates was identified. A checklist was completed throughout the study to observe the compliance to infection control measures by pharmacists (who prepare) and nurses (who administer) the ILE infusions. Results of septic neonatal cultures were taken from records.

RESULTS

Microbial contamination was found in 15.8% of ILE samples. The 2 most common pathogens found among positive samples were Klebsiella pneumoniae (29.2%) and Candida albicans (20.8%). Microbial contamination of repackaged syringes increased from 9.6% at 12 hours to 21.5% at 24 hours. This difference was found to be statistically significant (p = 0.044). A similar trend of predominance of those 2 pathogens, in both ILE and neonatal cultures, was observed. There was a statistically significant better performance of infection control measures of pharmacists rather than nurses. The K pneumoniae isolates (n = 7) showed antibiotic resistance in the following pattern: gentamicin (71.4%), cefazolin (85.7%), and cefoxitin (85.7%).

CONCLUSIONS

The rate of ILE contamination was less at 12 hours' than at 24 hours' infusion time. However, contamination rates at 12 hours were unacceptably high. Klebisella pneumoniae and C albicans were the most common pathogens isolated from ILE. Compliance with infection control measures was significantly worse among nurses compared with pharmacists.

A Mixed Lipid Emulsion Containing Fish Oil and Its Effect on Electrophysiological Brain Maturation in Infants of Extremely Low Birth Weight: A Secondary Analysis of a Randomized Clinical Trial

OBJECTIVE

To assess whether parenteral nutrition for infants of extremely low birth weight using a mixed lipid emulsion that contains fish oil influences electrophysiological brain maturation.

STUDY DESIGN

The study is a prespecified secondary outcome analysis of a randomized controlled trial of 230 infants of extremely low birth weight receiving a mixed (soybean oil, medium-chain triglycerides, olive oil, and fish oil; intervention) or a soybean oil-based lipid emulsion (control). The study was conducted at a single-level IV neonatal care unit (Medical University Vienna; June 2012 to October 2015). Electrophysiological brain maturation (background activity, sleep-wake cycling, and brain maturational scores) was assessed biweekly by amplitude-integrated electroencephalography (birth to discharge).

RESULTS

A total of 317 amplitude-integrated electroencephalography measurements (intervention: n = 165; control: n = 152) from 121 (intervention: n = 63; control: n = 58) of 230 infants of the core study were available for analysis. Demographic characteristics were not significantly different. By 28 weeks of postmenstrual age, infants receiving the intervention displayed significantly greater percentages of continuous background activity. Total maturational scores and individual scores for continuity, cycling, and bandwidth were significantly greater. Maximum maturational scores were reached 2 weeks earlier in the intervention group (36.4 weeks, 35.4-37.5) compared with the control group (38.4 weeks, 37.1-42.4) (median, IQR; P < .001).

CONCLUSIONS

Using a mixed parenteral lipid emulsion that contains fish oil, we found that electrophysiological brain maturation was accelerated in infants who were preterm.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT01585935.

Potential Nutritional and Metabolomic Advantages of High Fat Oral Supplementation in Pancreatectomized Pancreaticobiliary Cancer Patients

We examined the effect of high fat oral nutritional supplement (HFS) on the nutritional status, oral intake, and serum metabolites of postoperative pancreaticobiliary cancer patients. Pancreaticobiliary cancer patients were voluntarily recruited. The HFS group received postoperative oral high fat supplementation (80% of total calories from fat; n = 12) until discharge; the control group (non-HFS; n = 9) received none. Dietary intake, anthropometry, blood chemistry, nutritional risk index (NRI), and serum metabolites analyzed by liquid chromatography tandem mass spectrometry were evaluated. Overall, cumulative caloric supply via parental and oral/enteral routes were not different between groups. However, oral fat intake, caloric intake, and NRI scores of the HFS group were higher than those of the non-HFS group with increased oral meal consumption. Oral caloric, fat, and meal intakes correlated with NRI scores. Metabolomics analysis identified 195 serum metabolites pre-discharge. Oral fat intake was correlated with 42 metabolites relevant to the glycerophospholipid pathway. Oral high fat-specific upregulation of sphingomyelin (d18:1/24:1), a previously reported pancreatic cancer-downregulated metabolite, and lysophosphatidylcholine (16:0) were associated with NRI scores. Provision of HFS in postoperative pancreatic cancer patients may facilitate the recovery of postoperative health status by increasing oral meal intake, improving nutritional status, and modulating serum metabolites

Essential Fatty Acid Requirements and Intravenous Lipid Emulsions

Linoleic acid (LA) and α-linolenic acid (ALA) must be supplied to the human body and are therefore considered essential fatty acids. This narrative review discusses the signs, symptoms, diagnosis, prevention, and treatment of essential fatty acid deficiency (EFAD). EFAD may occur in patients with conditions that severely limit the intake, digestion, absorption, and/or metabolism of fat. EFAD may be prevented in patients requiring parenteral nutrition by inclusion of an intravenous lipid emulsion (ILE) as a source of LA and ALA. Early ILEs consisted solely of soybean oil (SO), a good source of LA and ALA, but being rich in LA may promote the production of proinflammatory fatty acids. Subsequent ILE formulations replaced part of the SO with other fat sources to decrease the amount of proinflammatory fatty acids. Although rare, EFAD is diagnosed by an elevated triene:tetraene (T:T) ratio, which reflects increased metabolism of oleic acid to Mead acid in the absence of adequate LA and ALA. Assays for measuring fatty acids have improved over the years, and therefore it is necessary to take into account the particular assay used and its reference range when determining if the T:T ratio indicates EFAD. In patients with a high degree of suspicion for EFAD, obtaining a fatty acid profile may provide additional useful information for making a diagnosis of EFAD. In patients receiving an ILE, the T:T ratio and fatty acid profile should be interpreted in light of the fatty acid composition of the ILE to ensure accurate diagnosis of EFAD.

Targeting Antioxidants to Interfaces: Control of the Oxidative Stability of Lipid-Based Emulsions

The oxidation of lipid-based emulsions and nanoemulsions strongly affects their overall quality and safety. Moreover, introduction of oxidatively unstable emulsions into biological systems either as an energy source in parenteral nutrition or as delivery systems of bioactives may promote oxidation "in situ" leading to the overproduction of reactive oxygen species, initiating new harmful oxidative reactions and increasing the oxidative damage. Addition of antioxidants, AOs, may help to prevent the oxidative degradation of unsaturated lipids. Nevertheless, prediction of the optimal antioxidant or set of antioxidants and their efficiency is still far from being completely understood because the site of reaction is often uncertain and because the effective concentrations of reactants in the different regions of the emulsion have been frequently overlooked. Furthermore, the absence of quantitative relationships between the hydrophobicity of the antioxidants and their partitioning among the oil, water, and interfacial regions hampers their optimal use. Here we investigated the effects of gallic acid and some of its alkyl derivatives on the oxidative stability of soybean oil-in-water emulsions and determined their effective concentrations in the different regions of the emulsion (aqueous, oil, and interface). The results provide physical evidence for the crucial role played by the interfacial region in the reaction between antioxidants and lipid radicals: a direct relationship between interfacial concentrations and the oxidative stability could be established. The results indicate that AOs accumulate in the interfacial region, where the effective concentration is 20-180 times higher than the stoichiometric concentrations. Control of the hydrophobicity of the AOs and of the surfactant concentration allows control of interfacial concentrations: the lower the concentration of surfactant employed, the higher the effective interfacial concentration.

Current Evidence for the Use of Smoflipid® Emulsion in Critical Care Patients for Parenteral Nutrition

There are strong data showing that malnutrition is highly prevalent in intensive care unit patients (20–50% in the worldwide), presenting a negative accumulated body energy balance. This results in an increased mortality, infections, and hospital length stay with high costs associated with the total treatment. Parenteral nutrition is the first option when the patient's physical condition is not suitable for oral nutrient intake. It is composed essentially by lipids as an energy source, metabolic, and structural function. However, these patients also require a mixture of essential and nonessential fatty acids (SMOF emulsions) to supply not only energy needs but also restore immunological, anti-inflammatory, and proregenerative functions. A revision of the safety and efficacy of Smoflipid® in patients requiring long-term parenteral nutrition was discussed here. Although controversial data are available indicating the contraindications or effectiveness of its use, most of studies presented indicate favorable benefits associated with improved clinical outcomes. The reported roles of this supplementation include positive immunomodulatory and anti-inflammatory effects, positive impact in liver function, reduction of hospital stay, and nosocomial infections as additional contributions to its energetic role, which in many cases results in reduced total costs per patient. Finally, many authors propose that the use of Smoflipid® should become a gold standard of parenteral nutrition in intensive unit care patients and that the costs associated with this supplement should not be limiting for its use, not only to improve the clinical outcome but also to reduce the treatment costs.

Nutritional Composition Assessment of 3000 Individualized Parenteral Nutrition Bags in a Tertiary Referral Hospital: Current Prescribing Patterns

Individualized parenteral nutrition is the most specialized type of nutritional support in the hospital setting. The composition and prescribing patterns for parenteral nutrition have evolved due to new emerging scientific evidence. In the last few years, there has been a tendency to increase the nitrogen and lipid content and decrease the carbohydrate content. To assess the prescribing pattern in a tertiary referral hospital in Spain, the nutritional composition of individualized parenteral nutrition was evaluated retrospectively from January to December of 2016. A total of 3029 parenteral nutrition units were analysed, corresponding to 257 hospitalized adult patients. Medical specialists in General Surgery and Haematology were the most common petitioners. The three most frequently prescribed parenteral nutrition formulae contained 13.4 (28.8%), 15.7 (19.54%) and 17.9 (17.79%) g of nitrogen. The quantity of carbohydrates and lipids showed a mean non-protein calories-to-nitrogen ratio of approximately 78:1 and a carbohydrate-to-lipid ratio that was near 50:50 in most cases. These results suggest a trend towards the administration of parenteral nutrition with a high content of nitrogen and smaller proportion of the non-protein components.

Inpatient outcomes of preterm infants receiving ω-3 enriched lipid emulsion (SMOFlipid): an observational study

Neonatal units have started to switch from using conventional soy-based to alternate lipid emulsions, like SMOFlipid. SMOFlipid has been associated with an improvement in biochemical parameters and delays progression of parenteral nutrition-associated liver disease (PNALD). This retrospective epoch study aimed to compare clinically relevant neonatal outcomes in preterm infants (< 32 weeks), receiving SMOFlipid versus Intralipid. We compared clinical outcomes in two epochs-epoch 1 (Intralipid, October 2013-June 2015) versus epoch 2 (SMOFlipid, July 2015-March 2017). Primary outcome studied was mortality and rates of severe neonatal morbidities. Univariate and multivariate regression was conducted to determine risk for mortality and PNALD. A total of 222 infants (epoch 1, 123 versus epoch 2, 99) were included in the study. A higher incidence of late onset sepsis (56 versus 30%, p < 0.005) was observed in epoch 1. There was no significant difference in mortality or rates of any other severe neonatal morbidity. The type of lipid emulsion did not have a significant effect on mortality or PNALD on regression analysis.

CONCLUSION

Use of SMOFlipid as the primary lipid emulsion seems to have minimal effect on rates of clinically important neonatal outcomes; however, long-term effects need to be further evaluated. What is Known: • Many neonatal units have started replacing traditional soy-based lipid formulations with SMOFlipid (ω-3 enriched lipid emulsion), as the primary lipid component in parenteral nutrition for preterm infants. • While there is evidence associating improved liver function and balanced essential fatty acid levels in infants receiving SMOFlipid, there is a lack of evidence evaluating relevant clinical outcomes in infants receiving SMOFlipid versus traditional lipid formulations. What is New: • The influence of SMOFlipid on a series of clinical outcomes in an at-risk preterm population is presented. • SMOFlipid appears to be well tolerated in preterm infants with minimal side effects, and some growth benefits seen.