456 - New Mode of Photo-protection of Neonatal Parenteral Nutrition: What Effect on Infused Ascorbic Acid?

Poster Number: 456
Publication Number: 456.2052

Background: Parenteral nutrition (PN) exposure to ambient light leads to the degradation of several nutrients, particularly vitamins, and the generation of oxidizing molecules, including peroxides. The rapid loss of ascorbic acid (AscA), an essential nutrient for antioxidant defense, is induced by the photo-excitation of riboflavin, leading to the generation of light-induced by-products, including ascorbylperoxide. Preterm infants are highly susceptible to oxidative stress, due to their reduced antioxidant defenses. The American Society for Parenteral and Enteral Nutrition (ASPEN) recommends photo-protecting PN to reduce peroxide contamination and optimize PN integrity. However, there is no available effective method of PN photo-protection. In this study we suggest a new procedure, offering complete PN photo-protection, that has allowed, in vitro, a 45% reduction in the generation of peroxides in PN solutions.

Objective: To assess the effectiveness of this new mode of photo-protection of PN in limiting the degradation of AscA and the generation of ascorbylperoxide in PN solutions.

Design/Methods: PN solutions, identical to those used in our NICU for extremely preterm infants, prepared in pharmacy, and infused over 24 hours as per the cycled lighting schedule, according to the current preparation and infusion procedure (control, PN L+, n=3) or the suggested photo-protection preparation and infusion procedure (intervention, PN L-, n=3). Samples collected at several times from 0h to 24h for AscA and its oxidized form (dehydroascorbic acid, DHA) measurements by capillary electrophoresis, and ascorbylperoxide measurements by LC-MS spectroscopy.

Results: Over 24 hours, 41 ± 1% (PN L+, n=3) of the prescribed dose of AscA is infused through current PN procedures. Double of this amount is infused through photo-protected PN solutions (p < 0.001; Figure 1), equivalent to 82 ± 3% (PN L-, n=3) of the AscA prescribed dose. Of the total vitamin C infused (AscA+DHA), the proportion of reduced form (AscA) infused is significantly higher in the photo-protected PN solutions (93 ± 2%, PN L-, n=3 versus 62 ± 1%, PN L+, n=3; p < 0.001). Due to the limited AscA loss in the photo-protected PN solutions, ascorbylperoxide levels are expected to be lower.

Conclusion(s): This new mode of photo-protection would not only reduce the contamination of PN solutions with oxidizing molecules, but also limit the degradation of antioxidant nutrients, such as AscA. The suggested mode of photo-protection contributed to PN integrity during PN bag time span, in order to better respond to infants’ nutritional requirements.