Intravenous Lipid Emulsions in the NICU

High carbohydrate is preferable to high lipid parenteral nutrition in healthy dogs undergoing prolonged sedation

Parenteral nutrition (PN) is commonly used in intensive care units (ICUs) and is associated with earlier hospital outcome. However, there is scarcity of information about the metabolic effects of PN caloric distribution for dogs. Considering the high tolerance of dogs to lipids and, also, that hospitalized animals usually present insulin resistance, PN formulation with high fat instead high glucose can provide metabolic benefits in this specie. This study evaluated two PN protocols, based on high lipid or high carbohydrate in 12 healthy dogs under sedation/ventilation during 24 h. For baseline data, blood samples were collected 24 h before the study beginning. After fasting, the dogs were anesthetized and put under mechanical ventilation without energy support for 12 h to obtain: daily energy expenditure (DEE), respiratory quotient (RQ), oxygen consumption (VO2), carbon dioxide production (VCO2), lactate, glucose, cholesterol, and triglycerides concentrations. After, the dogs were allocated into two groups: lipid-based energy group (LEG) and carbohydrate-based energy group (CEG). Both groups received the PN infusions at a rate of 3 mL/kg/h for 12 h. Blood tests were performed 12, 24, and 48 h after infusion's completion. VO2 increased after PN in LEG, increasing energy expenditure compared to CEG. RQ remained close to 1 in CEG, indicating carbohydrate preferential consumption. Triglycerides increased in both groups after propofol infusion, remaining higher in LEG until the end of the evaluation. Glycaemia increased in CEG compared to baseline. In conclusion, both PN protocols can be used in healthy animals undergoing prolonged sedation protocols. However, high lipid PN had higher VO2 and DEE, and resulted in higher triglycerides concentrations and lower glycaemia indexes than carbohydrate, making high carbohydrate PN preferable to high lipid PN. Therefore, for use in critically ill patients, the data obtained in this study should be extrapolated, taking into consideration the specificity of each case.

Hepatic dysfunction in patients receiving intravenous lipid emulsions

PURPOSE

Until recently, intravenous lipid emulsions (ILEs) have consisted of soybean oil (SO) only. This review addresses recent developments in the field, including the problem of intestinal failure associated liver disease (IFALD) that can occur with the use of ILEs in children and adults, and newer ILEs that may minimize and reverse IFALD.

RECENT FINDINGS

Cholestasis is the primary manifestation of IFALD in premature infants receiving ILEs, whereas in older children and adults, steatosis is predominant. Two alternative ILEs have been extensively investigated for both safety and efficacy. SMOF, an ILE containing medium chain triglyceride, soybean oil, olive oil and fish oil (FO), is now widely used in both children and adults. A newer FO ILE is approved for use in children only. However, in case reports FO ILE has been shown to improve IFALD in adults. A number of new studies suggest that cholestasis from ILEs is dose-related. IFALD does not improve in many patients after transition from SO to SMOF, but partial or complete replacement with FO can halt and reverse IFALD.

SUMMARY

Adverse hepatic effects from ILEs are to some extent dose-related. Overfeeding with fat or with carbohydrate, or simply providing excessive calories in general, may be responsible. More research is needed investigating dose-related effects of macronutrients on liver injury.

Exclusive Fish Oil Lipid Emulsion Rescue Strategy Improves Cholestasis in Neonates on Partially Fish Oil-Based Lipid Emulsion: A Pilot Study

Resolution of parenteral nutrition-associated liver disease has been identified in infants receiving SMOFlipid™ or a 100% fish oil lipid emulsion (FOLE). However, the effect of FOLE is unknown when the previous emulsion received is a mixed lipid emulsion containing fish oil. This observational pilot study reports data regarding the use of Omegaven™ after the diagnosis of cholestasis while receiving SMOFlipid™. We conducted a retrospective review of medical charts of neonates in which a partially fish oil-based lipid emulsion was replaced by a fish oil lipid emulsion at 1 g/kg/day due to cholestasis. Thirty-eight infants (92.1% preterm, being 44.7% born below 28 weeks' gestation), received FOLE. Birth weight was 1390 (743.0; 2298) grams. The age that cholestasis diagnosed was 15.0 (10.0; 24.8) days. The fish oil emulsion was administered for 38.5 (11.2; 51.8) days. In 73.7% (28/38) of the neonates, the cholestasis was resolved. In 34.2% (13/38), resolution happened before FOLE discontinuation. In addition, in the rest of the neonates (15) in whom cholestasis resolved, resolution occurred after FOLE discontinuation. Nine of the neonates died. In conclusion, the use of a 100% fish oil-based emulsion in neonates afflicted with cholestasis developed while on a partially fish oil-based emulsion is associated with a bilirubin decrease.

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.

Hypertriglyceridemia in Preterm Infants

Preterm and critically ill infants are at risk for hypertriglyceridemia (HTG). Common risk factors for HTG include prematurity, intravenous lipid emulsion dose and oil composition, reduced lipoprotein lipase activity, fetal growth restriction, sepsis, and renal failure. Despite these risk factors, clinicians lack a universally agreed upon definition for HTG and evidence-based approach to HTG management. This review provides a detailed overview of triglyceride and intravenous lipid emulsion metabolism and how this relates to specific HTG risk factors, along with some practical considerations for managing HTG in the neonatal population.

Lipids and Long Chain Polyunsaturated Fatty Acids in Preterm Infants

Fatty acids are critical bioactives for fetal and neonatal development. Premature delivery and current nutritional strategies pose several challenges in restoring fatty acid balance in the preterm infant. The impact on fatty acid balance and outcomes using lipid emulsions, enteral nutrition, and enteral supplements are reviewed, including a summary of the most recent large clinical trials of enteral fatty acid supplementation for the preterm infant. Research gaps remain in successfully implementing nutritional strategies to optimize fatty acid status in preterm infants.

Human Milk Lipids Induce Important Metabolic and Epigenetic Changes in Neonates

Lipids are a major source of energy during the fetal/neonatal period. Most are received from the mother, transplacentally during the intrauterine period or via maternal milk after birth. However, in addition to the known nutritional roles, lipids are now known to bind a variety of cellular receptors to regulate specific patterns in metabolism and gene expression. The expression of these receptors is regulated by various genetic and environmental stimuli, and ligation can activate positive-feedback loops in the expression and the activity of downstream signaling pathways. The authors summarize the role of lipid ligands, cognate receptors, epigenetic regulation, and downstream signaling.

Biochemical Parameters in Extremely Preterm Infants Receiving Mixed Lipid Emulsions

OBJECTIVE

A mixture of soybean, medium-chain triglycerides, olive, and fish oils (SMOF) contains higher α-tocopherol and n-3 polyunsaturated fatty acids and lower phytosterol content compared with conventional soybean oil lipid emulsions (SOLE). We sought to characterize plasma total fatty acid profiles (FAPs) and assess the tolerability of long-term SMOF therapy in extremely preterm infants.

METHODS

We retrospectively evaluated infants born <28 weeks gestational age who received at least 30 consecutive days of SMOF between July 2016 and June 2019. We evaluated monthly FAPs and biochemical tolerance to SMOF using direct bilirubin (DB) and triglyceride (TG) levels. Growth parameters were evaluated longitudinally until discharge.

RESULTS

Sixteen patients with median gestational age 24 weeks (IQR, 23-25 weeks) received SMOF for median 76 days (IQR, 52-130 days). Fourteen patients had necrotizing enterocolitis (NEC) requiring surgical intervention and 15 patients received SOLE for median 19 days (IQR, 14-26 days) prior to switching to SMOF. Median docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) levels were elevated, whereas the remaining fatty acid levels fell within reported reference ranges. There were no incidents of essential fatty acid deficiency (triene to tetraene ratio >0.2) or hypertriglyceridemia (TG >200 mg/dL) with a general downtrend in DB after the first month on SMOF. All growth Z-scores declined throughout hospital stay.

CONCLUSIONS

Infants who received SMOF had a more pronounced elevation in DHA than EPA, of which the clinical significance remains unknown. Growth Z-scores declined with SMOF but were confounded by a high prevalence of surgically treated NEC.

Essential Fatty Acid Deficiency in an Extremely Premature Infant With Intestinal Failure

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Intestinal Failure-Associated Liver Disease in Neonates

Intestinal failure-associated liver disease (IFALD) is common in neonates who suffer from intestinal failure and rely on parenteral nutrition. The etiology is multifactorial, relating to the infant's underlying cause of intestinal failure and other infant factors such as prematurity. Management of the disease includes transitioning to enteral feedings as soon as is safe for the infant. In infants who continue to rely on parenteral nutrition, alternative lipid emulsions and other medications may be used. This article reviews the epidemiology and factors that contribute to IFALD in neonates, in addition to management strategies.