Photoprotection of parenteral nutrition enhances advancement of minimal enteral nutrition in preterm infants

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.

Light protection of parenteral nutrition, cholestasis, and other prematurity-related morbidities in premature infants

INTRODUCTION

Parenteral Nutrition (PN) can lead to intestinal failure associated liver disease (IFALD). There are no human studies to date studying specifically the benefits of light-protection on neonatal IFALD. Recently, the European Medicines Agency and the American Society for Parenteral and Enteral Nutrition (ASPEN) both recommended full light protection of PN to reduce the risk of adverse clinical outcomes.

OBJECTIVE

The primary objective of this study was to evaluate the impact of light-protecting PN on the incidence of cholestasis and peak direct bilirubin levels in premature infants.

STUDY DESIGN

Retrospective chart review of preterm infants requiring PN for a minimum of 2 weeks with or without light-protection. After light protection of the PN solution, primary outcomes (including cholestasis and direct bilirubin levels) of both groups were compared. Secondary outcomes include evaluation of bronchopulmonary dysplasia (BPD), necrotizing enterocolitis (NEC), retinopathy of prematurity (ROP), sepsis and mortality.

RESULTS

A total of 50 preterm infants <37 weeks gestation were included, 25 infants in each group. There was a statistically significant decrease in the rate of cholestasis (12 vs. 3, p = 0.005), median peak direct bilirubin levels (1.7 vs. 0.9 mg/dL, p = 0.02) and total bilirubin levels (4.1 vs. 3.4, p = 0.05) in the light-protection group compared to no light-protection group. There was a decrease in the incidence of severe BPD (with an increase of mild BPD, resulting in the same overall BPD rate) in the light-protection compared to no light-protection group (7 vs. 15, p = 0.0223). There was no difference in NEC, ROP, sepsis or mortality.

CONCLUSION

Our study supports that the practice of light-protecting PN may reduce the incidence of IFALD in premature infants. Moreover, there was a trend toward decreased incidence of severe BPD in the light-protection group. Further light protection studies are needed to confirm these findings.

Better preterm parenteral nutrition practice

At birth preterm babies are unable to tolerate sufficient enteral nutrition to support growth and development. Parenteral nutrition provides a means to bridge the transition from placental transfer of nutrients to the establishment of enteral feeds. Despite preterm babies being one of the highest users of parenteral nutrition amongst all patient groups and that it has been in use in preterm infants for several decades, the evidence base for its use remains weak. There are several areas of uncertainty in practice, including the optimal and relative intakes of macronutrients and the optimal timing of initiation of parenteral nutrition after birth. High quality randomised controlled trials powered to detect differences in long term functional outcomes are needed to determine best practice in preterm parenteral nutrition practice.

ASPEN lipid injectable emulsion safety recommendations part 2: Neonate and pediatric considerations

Lipid injectable emulsions (ILEs) are complex pharmaceutical formulations intended as a source of energy and fatty acids for parenteral nutrition (PN) therapy. Part 1 of this series addressed issues associated with and safety recommendations pertaining to adult ILE use. Part 2 addresses ILE safety in neonatal and pediatric patients. Considerations for ILE use in the neonatal and pediatric populations differ from those of adults. For example, these patients often require higher doses compared with adult counterparts to support growth, development, and daily metabolic needs. ILE is also frequently administered as a separate infusion as opposed to in a total nutrient admixture owing to compatibility and stability issues and limitations to intravenous access in the neonatal and pediatric populations. ILE is the most frequent PN ingredient associated with PN errors occurring in the administration, prescribing, and transcribing processes. Concerns exist with use of in-line filters and repackaging of commercial products for infusion. ILE use in neonatal and pediatric patients has been associated with both minor and major adverse effects, which most often occur with doses exceeding manufacturer recommendations. Gaps in ILE best practices for neonatal and pediatric patients predispose to errors in the PN use system. This paper describes safe-use considerations for ILE products available in the United States in neonatal and pediatric patients, including indications, prescribing, order review, preparation, administration, and monitoring. This paper has been approved by the American Society for Parenteral and Enteral Nutrition (ASPEN) Board of Directors.

A systematic review of the definitions and prevalence of feeding intolerance in preterm infants

BACKGROUND & AIMS

Feeding intolerance (FI) is a common phenomenon experienced in preterm infants in neonatal intensive care units, as well as being a focus of many research studies into feeding methods, particularly in relation to comorbidities. There is no widely accepted definition of FI. This systematic review aimed to explore the range of definitions used for FI and provide an estimate of the prevalence amongst preterm infants.

METHODS

Searches were completed on MEDLINE (includes the Cochrane library), Embase, PsycInfo, CINAHL, NHS Evidence and Web of Science. Inclusion criteria; preterm infants in neonatal units, a clear definition of FI, >10 patients and be available in English language. Case reports were excluded.

RESULTS

One hundred studies were included. Definitions of FI were inconsistent. Studies were grouped according to definition used into: Group A - measuring gastric residual volume (GRV) only; group B - GRV and abdominal distension (AD); group C - GRV, AD and gastrointestinal symptoms (GI) which included any of vomiting, bilious vomiting and blood in stool; group D- GRV and GI; group E - AD and GI; group F - GI only and group G - any other elements used. Meta-analysis demonstrated that prevalence of FI between groups varied from 15 to 30% with an overall prevalence of 27% (95% confidence interval 23-31%). Group A had the highest prevalence. Review of time to full enteral feed was performed (37 studies) which demonstrated a range of 11.3-18.3 days depending on which FI definition used.

DISCUSSION

Definitions of FI in research are inconsistent, a similar finding to that seen in studies in both paediatric and adult critical care populations. The difficulty of defining FI in the preterm population is the concern regarding necrotising enterocolitis, with some studies using an overlap in their definitions, despite differing pathophysiology and management. Due to the heterogeneity of data obtained in this review regarding definitions used, further robust research is required in order to conclude which elements which should be used to define FI in this population.

PROSPERO NUMBER

CRD42019155596. Registered November 2019.

Recommendations for photoprotection of parenteral nutrition for premature infants: An ASPEN position paper

Although crucial in improving health outcomes in the preterm infants, parenteral nutrition (PN) is not without risk, especially if handled improperly. A growing body of evidence suggests that components of PN admixtures, including lipid injectable emulsions (ILEs), are susceptible to degradation, including oxidation when exposed to light (ie, photo-oxidation), resulting in the production of reactive oxygen species. Infants, especially those born preterm, are considered more susceptible to consequences of oxidative stress than children and adults. Oxidative stress is associated with bronchopulmonary dysplasia, retinopathy of prematurity, necrotizing enterocolitis, and intestinal failure-associated liver disease. The American Society for Parenteral and Enteral Nutrition (ASPEN) assembled a working group to provide recommendations on clinical practice surrounding photoprotection of PN.This Position Paper reviews the scientific literature on the formation of quantifiable peroxides and other degradation products when PN admixtures and ILEs are exposed to light and reports adverse clinical outcomes in premature infants exposed to PN. Recommendations for photoprotection of PN admixtures and ILEs are provided, as well as the challenges in achieving complete photoprotection with the equipment, supplies, and materials currently available in the US. ASPEN and the authors understand that the full implementation of complete photoprotection may not currently be feasible given current product availability; recommendations provided in this paper serve to represent the goal to which to strive as well as to highlight the importance of product availability to achieve these practices. This paper has been approved by the ASPEN Board of Directors.

Current strategies for managing intestinal failure-associated liver disease

Introduction: Intestinal failure-associated liver disease (IFALD) refers to hepatic dysfunction that results from prolonged parenteral nutrition (PN) use. IFALD is multifactorial in origin and remains a major cause of morbidity and mortality. Prior to 2004, IFALD was associated with mortality as high as 90% in infants who remained on PN greater than 1 year. The advent of new strategies for intravenous lipid emulsion (ILE) administration and improved catheter care now allow many patients to remain on PN and recover from this once fatal condition. Several additional treatment modalities are often used to further improve outcomes for IFALD patients and they are reviewed here.Areas covered: The etiology of IFALD is presented, as well as the rationale behind the use of ILEs that contain fish oil. Other management strategies are addressed, including the effects of several pharmacologic and nutritional interventions.Expert opinion: Like its etiology, the management of IFALD is multifactorial. Prompt recognition of patients at risk, avoiding macronutrient excess, and preventing central line associated bloodstream infections will improve outcomes. In patients who develop IFALD, the use of fish oil monotherapy seems to be efficacious. The most effective intervention, however, continues to be discontinuation of PN and achieving full enteral feedings.

Photoprotection But Not N-acetylcysteine Improves Intestinal Blood Flow and Oxidation Status in Parenterally Fed Piglets

OBJECTIVES

The purpose of the present study was to determine if protecting parenteral nutrition solutions from ambient light and supplementing with N-acetylcysteine (NAC) improves mesenteric blood flow, gut morphology, and oxidative status of parenterally fed neonates.

METHODS

Neonatal Yucatan miniature piglets (n = 23, 7-11 days old) were surgically fitted with central venous catheters and an ultrasonic blood flow probe around the superior mesenteric artery. Piglets were fed continuously for 7 days either light-protected (LP) or light-exposed (LE) complete parenteral nutrition that was enriched with either NAC or alanine (ALA).

RESULTS

There were no differences in body weight or overall gut morphology among groups after 7 days. Plasma concentrations of NAC were greater and total homocysteine lower in NAC- versus ALA-supplemented pigs on day 7 (N-acetylcysteine: 94 vs 7 μmol/L; P < 0.001; homocysteine: 14 versus 21 μmol/L; P < 0.005); plasma total glutathione was not affected. Hepatic lipid peroxidation was reduced by 25% in piglets that received LP parenteral nutrition (P < 0.05). The mesenteric artery blood flow decreased in all pigs between days 2 and 6 (P < 0.001) because of parenteral feeding. Photoprotection alone (LP-ALA) attenuated the decrease in mesenteric blood flow to 66% of baseline on day 6 compared with LE-ALA (37%; P < 0.05) and LP-NAC pigs (43%; P = 0.062); LE-NAC piglets had intermediate reductions in blood flow (55%).

CONCLUSIONS

Photoprotection of parenteral nutrition solutions is a simple, effective method to attenuate decline in blood flow to the gut and hepatic lipid peroxidation, which are both commonly associated with parenteral feeding.

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.

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.

Aspiration and evaluation of gastric residuals in the neonatal intensive care unit: state of the science

The routine aspiration of gastric residuals (GR) is considered standard care for critically ill infants in the neonatal intensive care unit (NICU). Unfortunately, scant information exists regarding the risks and benefits associated with this common procedure. This article provides the state of the science regarding what is known about the routine aspiration and evaluation of GRs in the NICU focusing on the following issues: (1) the use of GRs for verification of feeding tube placement, (2) GRs as an indicator of gastric contents, (3) GRs as an indicator of feeding intolerance or necrotizing enterocolitis, (4) the association between GR volume and ventilator-associated pneumonia, (5) whether GRs should be discarded or refed, (6) the definition of an abnormal GR, and (7) the potential risks associated with aspiration and evaluation of GRs. Recommendations for further research and practice guidelines are also provided.

Feeding intolerance: a concept analysis

Feeding intolerance is a well-known phenomenon in the NICU and is linked to morbidity and mortality in the premature infant. However, a universal definition for this concept is lacking. Properly defining a concept is a key step in a successful research project. A concept analysis is an examination of the fundamental elements of a concept to bring clarification and definition to the topic of interest. The purpose of this concept analysis was to clarify the phenomenon of feeding intolerance in the premature infant and to provide a universal conceptual and operational definition for researchers and clinicians to use in practice theory.

Inflammatory response in preterm infants is induced early in life by oxygen and modulated by total parenteral nutrition

The i.v. lipid emulsion (LIP) is a source of oxidants, which may stimulate inflammation. Coadministration of parenteral multivitamins (MVP) with LIP prevents lipid peroxidation in light-exposed total parenteral nutrition (TPN). We hypothesized that this modality of TPN administration affects systemic inflammation, which may be modulated by exposure to oxygen. Premature infants were allocated to three TPN regimens: control regimen - MVP coadministered with amino acid/dextrose exposed to ambient light, LIP provided separately (n = 9) - LIP+MVP light exposed (LE): MVP coadministered with light-exposed LIP (n = 9) - LIP+MVP light protected (LP): MVP coadministered with light-protected LIP (n = 8). In LE and LP, amino acid/dextrose was provided separately. On reaching full TPN, infants were sampled for IL-6 and IL-8 in plasma and the redox potential of glutathione in whole blood (E, mV). Data were compared (ANOVA) in infants exposed to low (<0.25) versus high (> or =0.25) FiO2. Patients (mean +/- SD: birth weight 797 +/- 172 g; GA 26 +/- 1 wk) had similar clinical characteristics in TPN groups. Cytokine levels correlated positively (p < 0.01) with FiO2 and E. High FiO2 stimulated an increase (p < 0.01) in cytokines in control regimen, whereas these markers remained unaffected by oxygen in the LE and LP groups. The choice of a TPN admixture may have important consequences on the systemic inflammatory response triggered by an oxidant stress.

Early life events, sex, and arterial blood pressure in critically ill infants

OBJECTIVE

To determine whether photo-protecting total parenteral nutrition in preterm infants influences arterial blood pressure differently according to gender. Blood pressure is influenced by complex mechanisms of vasomodulation. Oxidants are mediators and effectors in such reactions. Shielding total parenteral nutrition from light contributes to decrease the generation of peroxides. Girls may be better protected against an oxidant load than boys. We questioned whether shielding total parenteral nutrition may have cardiovascular effects that are influenced by gender.

DESIGN

A post hoc subgroup analysis of the effect of shielding parenteral nutrition from light.

SETTING

Neonatal intensive care unit.

SUBJECTS

Preterm infants <1000 g with indwelling arterial catheters who received light exposed (n = 20) or light protected (n = 20) parenteral nutrition.

INTERVENTIONS

Invasive monitoring, total parenteral nutrition.

MEASUREMENTS AND MAIN RESULTS

Arterial blood pressure was recorded hourly and compared between light exposed and light protected over the first week of life; timed average maximum velocity (m/s) was measured in the superior mesenteric artery by Doppler; presence of ductus arteriosus was documented by cardiac ultrasound. Data were analyzed by analysis of variance. No differences were noted between light exposed and light protected in clinical determinants that may influence blood pressure. There was an interaction (p < .01) between gender and total parenteral nutrition on blood pressure. In girls (n = 17), systolic and diastolic blood pressures were higher (p < .01) and heart rate lower (p < .01) during light exposed. There was no effect on BP observed in boys (n = 23). The linear correlation between timed average maximum velocity and systolic blood pressure was positive (p < .05). There was no echocardographic difference in hemodynamic variables between boys (n = 21) and girls (n = 9) who had a patent ductus.

CONCLUSION

Failure to shield total parenteral nutrition from light results in higher blood pressure in a selected population of critically ill female infants. This information adds to our understanding of the multiple determinants involved in optimizing arterial blood pressure in a critical care environment.

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.

Shielding parenteral nutrition from light: does the available evidence support a randomized, controlled trial?

BACKGROUND

Exposure of total parenteral nutrition to ambient light induces the generation of peroxides, creating oxidant stress, which potentially compounds complications of prematurity. Photograph protection of total parenteral nutrition reduces the peroxide load and has been shown to be associated with nutritional and biochemical benefits in animals and humans. It is unclear whether this reduction in peroxides from total parenteral nutrition leads to a reduction in the complications of prematurity, such as bronchopulmonary dysplasia. Our hypothesis was that shielding total parenteral nutrition from ambient light is linked to clinical benefits.

OBJECTIVE

The purpose of this work was to determine whether photograph protection of total parenteral nutrition (light protected), as compared with no photoprotection (light exposed), reduces the occurrence of bronchopulmonary dysplasia or death in preterm infants.

METHODS

The Canadian Neonatal Network provided data for infants born in 2006 at <28 weeks' gestation admitted to level 3 NICUs in Canada. A retrospective analysis was performed comparing bronchopulmonary dysplasia and death in infants who received light-exposed or light-protected parenteral nutrition. Data were analyzed by using logistic regression models. RESULTS. Thirteen NICUs offered partial light-protected (total parenteral nutrition bag only, intravenous tubing exposed) and 13 offered light-exposed parenteral nutrition; not a single NICU offered complete light-protected parenteral nutrition (total parenteral nutrition bag plus intravenous tubing). The incidence of bronchopulmonary dysplasia or death was 66% with light-protected (n = 428) vs 59% with light-exposed (n = 438) parenteral nutrition.

CONCLUSIONS

Partial photograph protection of total parenteral nutrition was not associated with a reduction in bronchopulmonary dysplasia or death as compared with no photograph protection; this relationship is confounded by covariates with strong associations with bronchopulmonary dysplasia. Partial photograph protection of total parenteral nutrition solutions confers no clinical benefit, while consuming valuable resources. A randomized, controlled trial is justified to determine whether there is a true "cause-and-effect" relationship between complete photoprotection of total parenteral nutrition and bronchopulmonary dysplasia or death.

Highlight Commentary on "Influence of lung oxidant and antioxidant status on alveolarization: Role of light-exposed total parenteral nutrition"

Bronchopulmonary dysplasia (BPD) is a frequent complication of premature newborns, particularly very low birth-weight babies (<1500 g). Undoubtedly multiple mechanisms contribute to the adverse outcomes associated with BPD but oxidative stress is one causative factor. In this issue of Free Radical Biology and Medicine, Lavoie et al. describe the increased peroxide generation when the multivitamin solution used for nutritional support, total parenteral nutrition (TPN), is exposed to ambient light. Because the premature newborn has limited antioxidant capacity, this increased oxidative burden from the TPN becomes increasingly significant. Infusion of this light-exposed solution in a newborn guinea pig decreased lung tissue vitamin C but not vitamin E. When the multivitamin and lipid solutions were mixed and then exposed to light, alveolarization of the developing lung was decreased. This study by Lavoie et al. highlights simple measures that can potentially decrease the oxidant burden delivered to this vulnerable population and improve alveolarization.

In preterm neonates, is the risk of developing bronchopulmonary dysplasia influenced by the failure to protect total parenteral nutrition from exposure to ambient light?

Light-exposed total parenteral nutrition (TPN) generates peroxides that contribute to an oxidant load. Shielding TPN from light protects against lung remodelling. In preterm infants, photoprotection of TPN is associated with a 30% reduction in bronchopulmonary dysplasia in a post-hoc analysis. This analysis provides justification for a randomized controlled trial.

Shielding parenteral multivitamins from light increases vitamin A and E concentration in lung of newborn guinea pigs

BACKGROUND & AIMS

Exposure of parenteral multivitamin preparation (MVP) to light generates peroxides. Light-exposed MVP induces an oxidant stress in lung but not in liver. This discrepancy suggests differences in handling of infused antioxidant vitamins between the two organs.

HYPOTHESIS

antioxidant capacity of lung depends on the MVP concentration and light protection of infused solutions.

METHODS

Protocol 1: four groups of three-day old guinea pigs received the base solution (5% dextrose + 0.45% NaCl) enriched with 0%, 1%, 2% and 3% MVP. Protocol 2: three further groups received the base solution + 2% MVP either light-exposed or light-protected or light-protected + 300 microM H2O2. After 4 days, lung and liver were sampled for vitamin determinations. Data were analyzed by ANOVA.

RESULTS

In lung, vitamins A-C-E reached a plateau with 1% MVP. In liver, vitamin A and E increased according to their concentration in solutions. Light exposure and added-H2O2 were associated with lower vitamin E in lung and liver. Retinol was higher in lung and lower in liver of animals receiving light-protected compared to light-exposed solutions.

CONCLUSIONS

Light protection of 1% MVP is a better way to improve the pulmonary oxidant-antioxidant balance than to increase MVP (>1%) in parenteral nutrition.

Parenteral nutrition

PURPOSE OF REVIEW

The past 12 months have seen advances in the safe use of intravenous nutrition and its place in the therapeutic armamentarium.

RECENT FINDINGS

Complications of intravenous nutrition and proposed optimal strategies to avoid them are considered, with particular attention to the hazards of hyperglycaemia. Intravenous nutrition in certain specified conditions is addressed, including its minor role in advanced malignancy. New details on the effects of amended lipid emulsions are presented, together with a meta-analysis of growth hormone and glutamine.

SUMMARY

Parenteral nutrition needs attention to detail if it is to be employed safely and effectively. Special care should be taken to maintain blood glucose in the normal range. There are currently insufficient data to warrant wholesale switching to novel lipid emulsions or the global use of glutamine or growth hormone.