Continuous infusion of methylprednisolone via paediatric parenteral nutrition: A pharmacokinetic animal study

A.S.P.E.N. clinical guidelines: parenteral nutrition ordering, order review, compounding, labeling, and dispensing

BACKGROUND

Parenteral nutrition (PN) is a high-alert medication available for patient care within a complex clinical process. Beyond application of best practice recommendations to guide safe use and optimize clinical outcome, several issues are better addressed through evidence-based policies, procedures, and practices. This document provides evidence-based guidance for clinical practices involving PN prescribing, order review, and preparation.

METHOD

A systematic review of the best available evidence was used by an expert work group to answer a series of questions about PN prescribing, order review, compounding, labeling, and dispensing. Concepts from the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) format were applied as appropriate. The specific clinical guideline recommendations were developed using consensus prior to review and approval by the American Society for Parenteral and Enteral Nutrition (A.S.P.E.N.) Board of Directors. The following questions were addressed: (1) Does education of prescribers improve PN ordering? (2) What is the maximum safe osmolarity of PN admixtures intended for peripheral vein administration? (3) What are the appropriate calcium intake and calcium-phosphate ratios in PN for optimal neonatal bone mineralization? (4) What are the clinical advantages or disadvantages of commercially available premade ("premixed") multichambered PN formulations compared with traditional/customized PN formulations? (5) What are the clinical (infection, catheter occlusion) advantages or disadvantages of 2-in-1 compared with 3-in-1 PN admixtures? (6) What macronutrient dosing limits are expected to provide for the most stable 3-in-1 admixtures? (7) What are the most appropriate recommendations for optimizing calcium (gluconate) and (Na- or K-) phosphate compatibility in PN admixtures? (8) What micronutrient contamination is present in parenteral stock solutions currently used to compound PN admixtures? (9) Is it safe to use the PN admixture as a vehicle for non-nutrient medication delivery? (10) Should heparin be included in the PN admixture to reduce the risk of central vein thrombosis? (11) What methods of repackaging intravenous fat emulsion (IVFE) into smaller patient-specific volumes are safe? (12) What beyond-use date should be used for (a) IVFE dispensed for separate infusion in the original container and (b) repackaged IVFE?

Early parenteral nutrition evokes a phenotype of autophagy deficiency in liver and skeletal muscle of critically ill rabbits

Muscular and hepatic abnormalities observed in artificially fed critically ill patients strikingly resemble the phenotype of autophagy-deficient mice. Autophagy is the only pathway to clear damaged organelles and large ubiquitinated proteins and aggregates. Fasting is its strongest physiological trigger. Severity of autophagy deficiency in critically ill patients correlated with the amount of infused amino acids. We hypothesized that impaired autophagy in critically ill patients could partly be evoked by early provision of parenteral nutrition enriched with amino acids in clinically used amounts. In a randomized laboratory investigation, we compared the effect of isocaloric moderate-dose iv feeding with fasting during illness on the previously studied markers of autophagy deficiency in skeletal muscle and liver. Critically ill rabbits were allocated to fasting or to iv nutrition (220 kcal/d, 921 kJ/d) supplemented with 50 kcal/d (209 kJ/d) of either glucose, amino acids, or lipids, while maintaining normoglycemia, and were compared with healthy controls. Fasted critically ill rabbits revealed weight loss and activation of autophagy. Feeding abolished these responses, with most impact of amino acid-enriched nutrition. Accumulation of p62 and ubiquitinated proteins in muscle and liver, indicative of insufficient autophagy, occurred with parenteral feeding enriched with amino acids and lipids. In liver, this was accompanied by fewer autophagosomes, fewer intact mitochondria, suppressed respiratory chain activity, and an increase in markers of liver damage. In muscle, early parenteral nutrition enriched with amino acids or lipids aggravated vacuolization of myofibers. In conclusion, early parenteral nutrition during critical illness evoked a phenotype of autophagy deficiency in liver and skeletal muscle.