Witold Brniak, Renata Jachowicz

Lipid peroxidation in parenteral nutrition admixtures – prooxidative and antioxidative factors, as well as their clinical significance
2019-11-30

Parenteral nutrition (PN) is a therapy used for over 50 years in a wide variety of clinical conditions in which oral or enteral feeding is impossible, insufficient or contraindicated. Due to the complex nature of the admixtures composition, they should always be prepared under the supervision of a trained pharmacist in a properly equipped parenteral nutrition unit of hospital pharmacy.

PN is a high-alert medication, which means that it can place patients at risk for significant harm when used in error, and even small errors can cause serious outcomes, including death. Parenteral nutrition admixtures contain dozens of active substances and excipients, and their preparation is associated with a high risk of interactions and instabilities. Despite many years of research, the role of individual factors affecting the stability of the mixture is still not fully understood. The major risk includes precipitation of calcium phosphate, aggregation of lipid emulsion droplets, and separation of its phases. Also many chemical reactions can take place during storage and administration. They can be affected by the storage temperature and time, composition of the admixture, particularly the type of lipid emulsion, addition of trace elements, and vitamins. What is more, the exposure to oxygen and light can cause formation of peroxides and other degradation products that can be harmful for the patients, particularly neonates, because their limited antioxidant reserves. Numerous in vitro an in vivo studies described many different methods of limiting peroxidation process in parenteral nutrition admixtures, including protection from light by covering admixture bag or syringe with polymer foil, as well as using dark color tubing to deliver PN. It was showed that peroxidation process can be also limited by using multilayer bags, impermeable to oxygen. In most studies, addition of multivitamins to admixture has protective effect on lipids, due to antioxidative properties of ascorbic acid and tocopherols, but in some studies the effect was opposite. It was caused by the reaction of light-induced riboflavin with ascorbates, thus the light protection seems to have the major importance. The aim of this review is to present available data on factors stimulating and inhibiting the process of peroxidation in parenteral nutrition admixtures, their importance for the health of nutritionally treated patients, as well as to describe the current guidelines on proper methods of protection of admixtures from peroxidation process.

Keywords: lipid peroxidation, total parenteral nutrition, parenteral lipid emulsion, multilayer bags, all in one (AIO), light protection.

© Farm Pol, 2019, 75(11): 638–647