Lipid peroxide and hydrogen peroxide formation in parenteral nutrition solutions containing multivitamins

Administering Parenteral Nutrition in the Neonatal Intensive Care Unit: Logistics, Existing Challenges, and a Few Conundrums

Use of parenteral nutrition (PN) in the neonatal intensive care unit (NICU) requires evaluating the need for central venous catheters, potential drug incompatibilities, unintentional exposures, and suboptimal energy and nutrient intake during the transition to full enteral nutrition. Risks of photooxidation reactions in PN components, refeeding syndrome, and excess early amino acid intake should prompt the reevaluation of routine practices. The goal of this paper is to review the practicalities, challenges, and conundrums of administering PN in the NICU.

Parenteral nutrition compatibility and stability: A comprehensive review

Several guidance documents support best practices across the stages of the parenteral nutrition (PN)-use process to optimize patient safety. The critical step of PN order verification and review by the pharmacist requires a contextual assessment of the compatibility and stability implications of the ordered PN prescription. This article will provide working definitions, describe PN component characteristics, and present a wide-ranging representation of compatibility and stability concerns that need to be considered prior to preparing a PN admixture. This paper has been approved by the ASPEN Board of Directors. This article is protected by copyright. All rights reserved.

Optimization of hemolysis, icterus and lipemia interference thresholds for 35 clinical chemistry assays

Objectives

Interference of chemistry assays by hemolysis, icterus and lipemia (HIL) was investigated on the Abbott Alinity c system. We sought to empirically establish optimized HIL index thresholds for the purposes of reporting HIL interference in a hospital laboratory and advising clinicians on the interpretation of laboratory results in the presence of hemolysis, icterus or lipemia.

Methods

HIL index values measured by spectrophotometry were compared with concentrations of hemoglobin, bilirubin and Intralipid. HIL interference of 35 Abbott Alinity chemistry assays was subsequently investigated by pairwise comparison of test results in pooled serum or plasma with those in test preparations spiked with hemolysate, bilirubin or Intralipid. Data generated from the interference experiments were critically assessed according to assay-specific acceptance criteria adapted from multiple sources, and optimized thresholds for HIL indices were established.

Results

Correlations between HIL index values and their corresponding concentrations of hemoglobin, bilirubin and Intralipid were, in general, very good within the ranges of interferent concentrations tested. Hemolysis significantly affected 12 of 35 assays, whereas bilirubin and Intralipid interfered with four and three assays, respectively. Both the direction and magnitude of Intralipid interference with the direct bilirubin assay were dependent on the concentrations of the analyte.

Conclusions

HIL interference of the Abbott Alinity clinical chemistry assays investigated in this study was not uncommon. At present, there are no universally accepted criteria for defining significant assay interference for clinical practice. In establishing acceptance criteria for defining assay interference, each assay should be assessed according to both analytical criteria and clinical relevance.

Neonatal parenteral nutrition affects the metabolic flow of glucose in newborn and adult male Hartley guinea pigs' liver

Extremely premature birth is associated with a permanent disruption of energy metabolism. The underlying mechanisms are poorly understood. The oxidative stress induced by parenteral nutrition (PN) during the first week of life is suspected to reprogram energy metabolism in the liver. Full-term male Hartley guinea pigs (to isolate PN from prematurity) receiving PN enriched or not with glutathione (to isolate PN effects from PN-induced oxidative stress effects) or an Oral Nutrition (ON) during the first week of life were used. At 1 week (neonatal) and 16 weeks (adult), measurements of liver glutathione (GSH and GSSG) and activities of three key enzymes of energy metabolism (glucokinase (GCK), phosphofructokinase (PFK), and acetyl-CoA carboxylase (ACC)) were performed. Differences between groups were reported if p ≤ 0.05 (Analysis of Variance). At 1 week, compared to ON, PN induced higher GSSG (oxidative stress), higher GCK activity, and lower PFK and ACC activity, the glutathione supplement prevented all PN effects. At 16 weeks, early PN induced lower GSSG (reductive stress) and lower GCK activity, which was prevented by added glutathione, and higher ACC activity independent of glutathione supplement. ACC was negatively associated (r2 = 0.33) with GSSG. Increased nicotinamide adenine dinucleotide phosphate levels confirmed the glucose-6-phosphate accumulation at 1 week, whereas our protocol failed to document lipid accumulation at 16 weeks. In adult male guinea pigs, neonatal exposure to PN affected glutathione metabolism leading to reductive stress (lower GSSG) and an altered metabolic flow of glucose. Partial prevention with glutathione supplementation suggests that, in addition to peroxides, other factors of PN are involved.

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

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

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

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

Physicochemical stable standard all-in-one parenteral nutrition admixtures for infants and children in accordance with the ESPGHAN/ESPEN guidelines

OBJECTIVE

Because there are almost no standard all-in-one parenteral nutrition admixtures available for infants and children, the aim was to develop standard two-compartment parenteral nutrition bags for different weight categories based on the ESPGHAN/ESPEN (European Society of Paediatric Gastroenterology, Hepatology and Nutrition/European Society for Clinical Nutrition and Metabolism) guidelines. The 1 g/kg/d lipid version for the 3 to 10 kg weight category (PED1) was assessed for short- and long-term physicochemical stability with the ability to add additional electrolytes (PED1+E).

METHODS

The lipid compartment A and the all-in-one admixture of A + B + vitamins + trace elements were assessed physically by visual inspection, Sudan red test, pH measurement, and lipid droplet size distribution. Chemical stability for compartment A was evaluated by quantitative analyses of non-esterified fatty acids and peroxide content. The glucose-amino acid-electrolyte compartment B was evaluated physically by visual inspection, measuring particle contamination and pH. Chemical stability was assessed by discoloration, quantitative analyses of glucose, and the amino acids L-cysteine, L-tyrosine, and L-tryptophan.

RESULTS

No phase separation or coalescence occurred, and the mean droplet size diameter did not exceed 0.5 µm. Peroxide content and non-esterified fatty acids concentration of compartment A remained well below the limit of acceptation. No precipitation was detected for compartment B; only a slight yellow discoloration was noted at 80 d. Concentrations of glucose, L-tyrosine, and L-tryptophan remained stable; only L-cysteine decreased significantly from its initial concentration.

CONCLUSION

The two-compartment PED1 and PED1+E admixtures are stable up to 80 d 2° to 8°C + 24 h room temperature (RT) with an additional 7 d 2° to 8°C + 48 h RT after mixing and addition of vitamins and trace elements.

Adult Consequences of Extremely Preterm Birth: Cardiovascular and Metabolic Diseases Risk Factors, Mechanisms, and Prevention Avenues

Extremely preterm babies are exposed to various sources of injury during critical stages of development. The extremely preterm infant faces premature transition to ex utero physiology and undergoes adaptive mechanisms that may be deleterious in the long term because of permanent alterations in organ structure and function. Perinatal events can also directly cause structural injury. These disturbances induce morphologic and functional changes in their organ systems that might heighten their risks for later adult chronic diseases. This review examines the pathophysiology of programming of long-term health and diseases after preterm birth and associated perinatal risk factors.

Practical handling of AIO admixtures - Guidelines on Parenteral Nutrition, Chapter 10

All-in-one admixtures (AIO-admixtures) provide safe, effective and low-risk PN (parenteral nutrition) for practically all indications and applications. Water, energy (carbohydrates and lipids), amino acids, vitamins and trace elements are infused together with PN either as industrially-manufactured AIO admixtures provided as two- or three-chamber bags (shelf life usually more than 12 months) completed with electrolytes and micronutrients where appropriate or as individually compounded ready-to-use AIO admixtures (compounding, usually prepared by a pharmacy on either a daily or weekly basis and stored at 2–8°C). Physico-chemical and microbial stability of an AIO admixture is essential for the safety and effectiveness of patient-specific PN, and its assurance requires specialist pharmaceutical knowledge. The stability should be documented for an application period of 24 (–48) hours. It is advisable to offer a limited selection of different PN regimes in each hospital. For reasons of drug and medication safety, PN admixtures prepared for individual patients must be correctly labelled and specifications for storage conditions must also be followed during transport. Monitoring is required where applicable. Micronutrients are usually administered separately to AIO admixtures. In case compatibility and stability have been well documented trace elements and/or combination preparations including water-soluble or water-soluble/fat soluble vitamin supplements can be added to PN admixtures under strict aseptic conditions. AIO admixtures are usually not used as vehicles for drugs (incompatibilities).

Effects of light exposure on total parenteral nutrition and its implications in the neonatal population

Total parenteral nutrition (TPN) is a necessary form of nutrition in neonates with functional or anatomical disruption of the digestive tract. However, laboratory and human investigation have shown that exposure of the TPN solution to light causes the formation of peroxides and other degradation products that are quantifiable in experimental TPN solutions, laboratory animals, and neonates. Premature neonates are at a higher risk for the development and progression of peroxide damage due to their relative lack of antioxidant and free radical scavenger reserves. Furthermore, cell damage seen in a number of neonatal disease states is exacerbated by the presence of peroxides that are generated via intrinsic pathologic processes and from exogenous sources such as TPN. Numerous studies show that the formation of TPN photodegradation products can be slowed or prevented by the application of various light protection mechanisms. While it is not yet known if minimizing TPN associated photodegradation byproducts has a significant direct effect on preventing or mitigating the overall clinical course of some neonatal disease states, it is becoming increasingly clear that light protecting TPN can avoid specific metabolic complications in neonatal patients. It is prudent to implement mechanisms that prevent photodegradation of TPN components from the manufacturer source to the point of patient administration.

Demographic and nutritional factors associated with prolonged cholestatic jaundice in the premature infant

OBJECTIVE

The primary aim of this study was to determine if an association exists between amino-acid levels and development of cholestasis. The secondary aim of our amino-acid dose comparison trial was to identify factors associated with the development of prolonged cholestatic jaundice.

STUDY DESIGN

We compared demographic characteristics and amino-acid levels in neonates who developed cholestasis with those who did not. Parenteral-associated cholestatic liver disease was defined as a direct serum bilirubin above 5 mg per 100 ml any time during the first 28 days after birth in neonates with no history of biliary atresia or viral hepatitis. We obtained filter paper blood spots for amino acid and acylcarnitine measurements on the day of randomization and days 7 and 28 of age to identify a profile of values that could be used to identify neonates with evidence of abnormal liver function.

RESULT

We enrolled 122 neonates in our study; 13 (10.7%) developed cholestasis. Neonates who developed cholestasis were more immature, had lower birth weight, were exposed to parenteral nutrition for a longer period, had a higher cumulative dose of amino acids, were less often on enteral nutrition by day 7 of age, more often had a patent ductus arteriosus and severe intraventricular hemorrhage and were more commonly treated with steroids by 28 days of age. Amino acid and acylcarnitine values were not different for the two groups on the day of randomization. On day 7 (parenteral phase of nutrition), blood urea nitrogen, citrulline, histidine, methionine and succinyl carnitine were higher, and serine, glutamate and thyroxine levels were lower in the neonates who developed cholestasis than in who did not.

CONCLUSION

Cholestasis remains an important complication of parenteral nutrition, and several clinical and biochemical factors may be helpful in identifying high-risk patients.

Parenteral nutrition-associated liver disease and the role for isolated intestine and intestine/liver transplantation

Parenteral nutrition-associated liver disease (PNALD) is the most devastating complication of long-term parenteral nutrition therapy. Because its progression is typically insidious and its long-term consequences are generally underappreciated, PNALD is often recognized too late, when liver injury is irreversible. When end-stage liver disease (ESLD) develops in these patients, most potential interventions are futile and transplantation of both an intestine and a liver becomes the only viable option, despite the relatively poor outcomes associated with this combined procedure. Although likely multifactorial in origin, the etiology of PNALD is poorly understood. Early clinical intervention with a combination of nutritional, medical, hormonal, and surgical therapies can be effective in preventing liver disease progression. If these interventions fail, intestinal transplantation should be performed expeditiously before development of ESLD mandates simultaneous inclusion of a liver graft as well.

Stability of total nutrient admixtures in reference to ambient temperatures

OBJECTIVE

To evaluate the stability of emulsions under different temperatures simulating clinical conditions of storage and exposure during infusion, five total nutrient admixture formulas in this institution were analyzed: adult, patients with hepatic failure, infants, stressed patients, and patients with renal failure.

METHODS

Each mixture was allocated in a sterile 100-mL glass bottle, which was prefilled and refilled with nitrogen gas. Bottles were stored at 4 degrees C for 0 d, 3 d, and 7 d and then exposed to three different temperatures: usual room temperature (18 degrees C to 25 degrees C), high (>28 degrees C) in a water bath, or storage (4 degrees C) for 24 and 48 h. The gross inspection of the emulsions and parallel measurements of pH, particle sizes, divalent ions, peroxide levels, and microbial cultures were performed.

RESULTS

Every lot was stable near 18 degrees C, but 8 of 10 lots stored for 7 d (25 degrees C and >28 degrees C) and 15 of 20 lots stored for 3 and 7 d (25 degrees C and >28 degrees C) showed coalescence. The overall coalescence incidences by storage, exposure, and heat were statistically significant (P < 0.005).

CONCLUSION

For the safety of total nutrient admixtures, special attention is required to keep the ambient temperature below 28 degrees C and completely exclude air from the container.

Peroxidation potential of lipid emulsions after compounding in all-in-one solutions

OBJECTIVES

We investigated the peroxidation potential of fat emulsions in all-in-one solutions (AIOs).

METHODS

Three 20% emulsions were compared: soybean oil (SO; 60% polyunsaturated fatty acids [PUFAs], alpha-tocopherol:PUFAs = 0.44), soybean plus medium-chain triacylglycerol (SO-MCT; 31% PUFAs, alpha-tocopherol:PUFAs = 0.35), and olive oil (OO; 21% PUFAs, alpha-tocopherol:PUFAs = 1.42). For each emulsion, six AIO solutions were prepared by adding 250 mL of emulsion to a lipid-free solution. Lipid peroxide (LPX) and malondialdehyde (MDA) concentrations were evaluated in fat emulsions, lipid-free solutions, and AIOs immediately (T0) and 24 h (T24) after lipid addition. Statistical analysis was done with analysis of variance.

RESULTS

Fat emulsion LPX in SO-MCT was lower than that in SO (P = 0.015) and OO (P = 0.024); LPX in SO was greater than that in OO (P = 0.013); MDA in SO was greater than that in SO-MCT (P = 0.001) and OO (P = 0.013); and MDA in SO-MCT was greater than that in OO (P = 0.001). In comparison with MDA at AIO-T0, MDA at AIO-T24 increased in SO (P = 0.005) and SO-MCT (P < 0.001) and decreased in OO (P = 0.003); at AIO-T24, LPX was greater in SO, but not significantly.

CONCLUSIONS

In AIO bags, LPX occurred within 24 h after the addition of the lipid emulsion and seemed to be directly related to the PUFA content and inversely related to the alpha-tocopherol:PUFA ratio of the emulsion.

Nutrition in the neonatal intensive care unit: how do we reduce the incidence of extrauterine growth restriction?

Extrauterine growth restriction is a major clinical problem for prematurely born neonates, especially critically ill preterm neonates, and malnutrition in the neonatal intensive-care unit remains common. There are numerous perceived risks to initiation of adequate nutritional support. How many of these factors pose a real risk to health outcomes is less clear. Current nutritional support does not prevent extrauterine growth restriction and the consequences of malnutrition are both acute and delayed. Our clinical approach to providing nutritional support impacts neonatal morbidity and long-term neuro developmental outcomes. While more and better evidence is needed to help guide best practices, this gap should not prevent neonatologists from using the observations in this review to improve their current practice. There is evidence that changes in nutritional support can have a positive influence on growth. These include early administration of intravenous amino acids and lipids, minimal enteral nutrition, and supplemented formula and human milk. Simply recognizing the degree of growth failure by monitoring weight and focusing on the accruing deficit should encourage clinicians to increase nutritional support to enhance recovery growth. Continued research is needed to define the efficiency of early feeding, more rapid advancements in nutritional support, protein needs, the optimal composition of breast-milk supplements, the etiology of necrotizing enterocolitis, and perhaps most importantly, the health consequences of extrauterine growth restriction.

Multivitamin solutions for enteral supplementation: a source of peroxides

OBJECTIVE

We investigated whether solutions of enteral vitamin supplementation are involved in the generation of peroxides and whether that contamination is biologically significant.

METHODS

Peroxide contents of oral multivitamin preparations were measured over 3 wk after the initial opening of the containers. In selected premature infants (younger than 35 wk gestation), urinary peroxides were measured after initiating oral multivitamin supplementation.

RESULTS

Peroxides in multivitamin solutions for enteral use are predominantly organic peroxides because they resist catalase. After the initial opening of the containers, there was a two-fold increase in total peroxides levels (P < 0.05) even in the preparation without riboflavin, a catalyst for the generation of peroxides. Initiation of oral vitamin supplementation was associated with increased (P < 0.05) urine peroxide levels. The high organic peroxide load did not correlate with its urinary excretion, mostly in the form of H(2)O(2). The excretion of H(2)O(2) corresponded to its oral intake from the multivitamin solution.

CONCLUSIONS

Compared with parenteral multivitamin solutions, the enteral preparations contained higher organic peroxide levels starting with the initial opening of the bottles. The increased urinary excretion of H(2)O(2) after enteral multivitamin supplementation suggested a systemic diffusion of peroxides or of components of the multivitamin preparation responsible for the generation of peroxides. This oxidant load was not quenched by the immature antioxidant defenses of premature infants.