Parenteral nutrition in clinical practice: International challenges and strategies

PURPOSE

Parenteral nutrition (PN) is an established therapy when oral/enteral feeding is not sufficient or is contraindicated, but nevertheless PN remains a complex, high-alert medication that is susceptible to errors that may affect patient safety. Over time, considerable progress has been made to make PN practices safer. The purpose of this article is to address ongoing challenges to improve the PN use process from prescription to administration and monitoring, and to outline practical aspects fostering the safety, quality, and cost-effectiveness of PN, as discussed at the International Safety and Quality of PN Summit.

SUMMARY

Opportunities to improve the PN use process in clinical practice include the promotion of inter-disciplinary communication, vigilant surveillance for complications, staff education to increase competency, and more consistent use of advanced technologies that allow automated safety checks throughout the PN process. Topics covered include considerations on PN formulations, including the value of intravenous lipid emulsions (ILEs), trends in compounding PN, the current and future role of market-authorized multi-chamber PN bags containing all 3 macronutrients (amino acids, glucose/dextrose, and ILE) in the United States and in Europe, and strategies to cope with the increasing global problem of PN product shortages.

CONCLUSION

This review outlines potential strategies to use in clinical practice to overcome ongoing challenges throughout the PN use process, and ultimately promote PN patient safety.

Lipid-Enriched Parenteral Nutrition and Bloodstream Infections in Hospitalized Patients: Is It a Real Concern?

Today, few clinicians are still convinced that lipids are sepsis risk factors in patients receiving parenteral nutrition. This dogma is principally based on old literature. This review deals with the most recent literature search that provided up-to-date data over the past ten years. Systematic research was performed on Pubmed, MEDLINE, and Web of Science. The recent evidence does not justify the exclusion of lipid emulsions in patients receiving parenteral nutrition for fear of bloodstream infection risk. Moreover, lipids represent a substantial proportion of the energy source providing essential fatty acids, potentially improving clinical outcomes in patients often malnourished. Understanding the actual risk factors of sepsis during parenteral nutrition is necessary to optimize patient nutritional status and care and avoid essential fatty acid deficiency. There is an urgent need to make updated nutrition training available at all levels of medical education.

Effects of lipid emulsions on the formation of Escherichia coli-Candida albicans mixed-species biofilms on PVC

Patients receiving lipid emulsions are at increased risk of contracting catheter-related bloodstream infections (CRBSIs) in the clinic. More than 15% of CRBSIs are polymicrobial. The objective of this study was to explore the effects of lipid emulsions on the formation of Escherichia coli (E. coli)–Candida albicans (C. albicans) mixed-species biofilms (BFs) on polyvinyl chloride (PVC) surfaces and the underlying mechanism. Mixed-species BFs were produced by coculturing E. coli and C. albicans with PVC in various concentrations of lipid emulsions. Crystal violet staining and XTT assays were performed to test the mixed-species BF biomass and the viability of microbes in the BFs. The microstructures of the BFs were observed by an approach that combined confocal laser scanning microscopy, fluorescence in situ hybridization, and scanning electron microscopy. The study found that lipid emulsions could promote the formation of E. coli–C. albicans mixed-species BFs, especially with 10% lipid emulsions. The mechanism by which lipid emulsions promote mixed-species BF formation may involve significant upregulation of the expression of the flhDC, iha, HTA1, and HWP1 genes, which are associated with bacterial motility, adhesion, and BF formation. The results derived from this study necessitate strict aseptic precautions when handling lipid emulsions and avoiding the use of high concentrations of lipid emulsions for as long as possible.

Cost-Effectiveness of Parenteral Nutrition Containing ω-3 Fatty Acids in Hospitalized Adult Patients From 5 European Countries and the US

Background

ω‐3 Fatty acid (FA)–containing parenteral nutrition (PN) is associated with improvements in patient outcomes and with reductions in hospital length of stay (HLOS) vs standard PN regimens (containing non–ω‐3 FA lipid emulsions). We present a cost‐effectiveness analysis of ω‐3 FA–containing PN vs standard PN in 5 European countries (France, Germany, Italy, Spain, UK) and the US.

Methods

This pharmacoeconomic model was based on estimates of ω‐3 efficacy reported in a recent meta‐analysis and data from country‐specific sources. It utilized a probabilistic discrete event simulation model to compare ω‐3 FA–containing PN with standard PN in a population of critically ill and general ward patients. The influence of model parameters was evaluated using probabilistic and deterministic sensitivity analyses.

Results

Overall costs were reduced with ω‐3 FA–containing PN in all 6 countries compared with standard PN, ranging from €1741 (±€1284) in Italy to €5576 (±€4193) in the US. Expenses for infections and HLOS were lower in all countries for ω‐3 FA–containing PN vs standard PN, with the largest cost differences for both in the US (infection: €825 ± €4001; HLOS: €4879 ± €1208) and the smallest savings in the UK for infections and in Spain for HLOS (€63 ± €426 and €1636 ± €372, respectively).

Conclusion

This cost‐effectiveness analysis in 6 countries demonstrates that the superior clinical efficacy of ω‐3 FA–containing PN translates into significant decreases in mean treatment cost, rendering it an attractive cost‐saving alternative to standard PN across different healthcare systems.

Controversies in the Use of Lipid Injectable Emulsion in Hospitalized Patients

Soybean oil-based lipid injectable emulsion (SO-based ILE) is an 18-carbon, ω-6 macronutrient providing a concentrated source of calories, which can be administered in or with parenteral nutrition to patients unable to tolerate or consume adequate enteral nutrition. Beyond the provision of energy, SO-based ILE provides linoleic and linolenic acid, 2 essential fatty acids necessary for the prevention of essential fatty acid deficiency. However, SO-based ILE with its high levels of ω-6 fatty acids, long-chain triglycerides, phospholipid emulsifiers, and glycerin has been associated with worsening clinical outcomes, including increase of infections, lengthier intensive care and hospital stay, and prolonged mechanical ventilation. Recognizing this, studies have investigated omitting SO-based ILE in the critically ill patient for the first 7 days to observe if clinical outcomes are improved. Unfortunately, there is extremely limited research, and what is available is controversial. National guidelines have analyzed the studies, and they too are challenged to define a clear, high quality of evidence recommendation. It is important for the healthcare clinician to understand the research around this controversy to make best decisions for their patients.

Updates in Nutrition Support for Critically Ill Adult Patients

Specialized nutrition support is often employed in critically ill patients who are unable to maintain volitional intake. The Society of Critical Care Medicine (SCCM) and American Society for Parenteral and Enteral Nutrition (A.S.P.E.N.) recently updated guidelines for the provision of nutrition support in critically ill patients. The purpose of this review is to summarize key changes from the previous guidelines as they relate to recently published literature, which will aid the hospital pharmacist in optimizing nutrition support therapies in the critical care setting.

Parenteral Nutrition and Lipids

Lipids have multiple physiological roles that are biologically vital. Soybean oil lipid emulsions have been the mainstay of parenteral nutrition lipid formulations for decades in North America. Utilizing intravenous lipid emulsions in parenteral nutrition has minimized the dependence on dextrose as a major source of nonprotein calories and prevents the clinical consequences of essential fatty acid deficiency. Emerging literature has indicated that there are benefits to utilizing alternative lipids such as olive/soy-based formulations, and combination lipids such as soy/MCT/olive/fish oil, compared with soybean based lipids, as they have less inflammatory properties, are immune modulating, have higher antioxidant content, decrease risk of cholestasis, and improve clinical outcomes in certain subgroups of patients. The objective of this article is to review the history of IVLE, their composition, the different generations of widely available IVLE, the variables to consider when selecting lipids, and the complications of IVLE and how to minimize them.

Parenteral Nutrition and Infection Risk in the Intensive Care Unit: A Practical Guide for the Bedside Clinician

The safety of parenteral nutrition (PN) administration in critically ill patients has been the subject of much controversy. Historically, PN administration has been associated with an increased risk of bacterial and fungal infections, leading to significant morbidity and mortality. Much of the data showing increased infectious complications compared with either no nutrition or enteral nutrition was derived from early studies conducted in the 1980s-2000s. Poor glucose control and hyperalimentation are confounding factors in many early studies, making it difficult to determine the true PN infection risks. While PN studies conducted during the past 10 years have failed to show the same infection rates, these risks continue to be cited as dogma. Potential reasons for such discordant results include improved glycemic control, avoidance of overfeeding, and improved sterility and central venous catheter care. Understanding the true infectious risk of PN administration in the intensive care unit is necessary to optimize patient care, as inappropriately withholding such nutrition is potentially deleterious. This review is meant to serve as a practical guide to the bedside clinician who is evaluating the risks and benefits of initiating PN in a critically ill patient. Each component of PN will be evaluated based on risk of infection, and the potential ways to mitigate risks will be discussed.

Three-in-one parenteral nutrition in neonates and pediatric patients: risks and benefits

Parenteral nutrition (PN) is a life-sustaining therapy designed to deliver essential nutrients to patients unable to meet nutrition needs via the enteral route. PN may be delivered via a 2-in-1 system (one solution containing amino acids, dextrose, electrolytes, vitamins, minerals, and fluids and one solution containing intravenous fat emulsions [IVFEs]) or via a 3-in-1 system (all nutrients mixed in one container). Although the use of 3-in-1 PN solutions is not necessarily therapeutically advantageous, certain benefits may exist such as the potential to reduce the risk of contamination due to decreased manipulations; ease of administration, particularly in the home care setting; possible cost savings; and reduced IVFE wastage. However, the incorporation of IVFE in 3-in-1 solutions also presents unique risks for the neonatal and pediatric population such as decreased stability, increased lipid globule size, decreased sterility and the potential for increased microbial growth/infectious complications, the need to use a larger filter size, precipitation and compatibility risks, and an increased chance of catheter occlusion. This review outlines the unique issues and challenges to be considered when formulating neonatal and pediatric 3-in-1 PN admixtures. While 3-in-1 PN solutions may be advantageous for certain pediatric populations, specifically those dependent on home PN, the risks do not outweigh the benefits in neonatal patients, and use should be avoided in this population.