Catherine M. Crill

The use of carnitine in pediatric nutrition.

Carnitine is synthesized endogenously from methionine and lysine in the liver and kidney and is available exogenously from a meat and dairy diet and from human milk and most enteral formulas. Parenteral nutrition (PN) does not contain carnitine unless it is extemporaneously added. The primary role of carnitine is to transport long-chain fatty acids across the mitochondrial membrane, where they undergo beta-oxidation to produce energy. Although the majority of patients are capable of endogenous synthesis of carnitine, certain pediatric populations, specifically neonates and infants, have decreased biosynthetic capacity and are at risk of developing carnitine deficiency, particularly when receiving PN. Studies have evaluated for several decades the effects of carnitine supplementation in pediatric patients receiving nutrition support. Early studies focused primarily on the effects of supplementation on markers of fatty acid metabolism and nutrition markers, including weight gain and nitrogen balance, whereas more recent studies have evaluated neonatal morbidity. This review describes the role of carnitine in metabolic processes, its biosynthesis, and carnitine deficiency syndromes, as well as reviews the literature on carnitine supplementation in pediatric nutrition.

Iodine in Enteral and Parenteral Nutrition

Iodine deficiency (ID) has multiple adverse effects on growth and development due to inadequate thyroid hormone production. Methods for assessment of iodine nutrition in individuals include the urinary iodine concentration (UI), thyroid size and thyroid function tests. The UI measured in several repeat 24-h urine samples can detect inadequate iodine intake in individuals receiving enteral or parenteral nutrition (PN) and allow for iodine supplementation before the onset of hypothyroidism. A daily dose of 1 microg iodine/kg body weight is currently recommended for children receiving PN, but this is far below their requirements. Daily iodine requirements in adults receiving enteral nutrition or PN are estimated to be 70-150 microg, but most PN formulations do not contain iodine. Despite this, ID has been unlikely because absorption from iodine-containing skin antiseptics and other adventitious sources can provide sufficient iodine. However, if chlorhexidine replaces iodine-containing antiseptics for catheter care, ID may occur during long-term PN, and periodic testing of UI and thyroid function may be prudent. Infants may be particularly vulnerable to ID because of their small thyroidal iodine store. In this review, we describe three recent patients (an infant, a child and an adult) who developed ID and thyroid hypofunction during PN.

Enteral Fish Oil for Treatment of Parenteral Nutrition‐Associated Liver Disease in Six Infants with Short‐Bowel Syndrome

Study Objective. To evaluate the use of enteral fish oil for the treatment of parenteral nutrition‐associated liver disease (PNALD).

Upper Gastrointestinal Tract Bleeding in Critically Ill Pediatric Patients

Similar to adults, children under physiologic stress can develop an imbalance in defensive (mucosal layer, motility) and aggressive (gastric acid, bile salts, enzymes) factors responsible for maintaining a healthy gastrointestinal tract. Hypoxia in the gastrointestinal tract likely disrupts the defensive factors, thereby permitting damage by aggressive factors to upper gastrointestinal epithelium that may progress to stress ulceration and acute upper gastrointestinal tract bleeding (UGIB). The basic pathophysiology may be similar in children and adults; however, differences in the time to developing ulceration, ulcer location, and number of ulcers have been reported. Functional development of the gastrointestinal tract is influenced by disease, gestational and postnatal age, and exposure to and type of enteral feedings, thereby confounding the development and prophylaxis of UGIB in neonates and infants. In addition, pharmacotherapy decisions are often complicated by drug administration issues and adverse effects.

Evaluation of microbial contamination associated with different preparation methods for neonatal intravenous fat emulsion infusion.

PURPOSE Microbial contamination associated with different methods of neonatal intravenous fat emulsion (IVFE) preparation and delivery was evaluated. METHODS Sterility testing was performed on IVFE dispensed via three different methods: (1) in the original container (n = 60), (2) repackaged into a syringe (n = 90), and (3) drawdown of the original container (n = 60). At the end of each infusion (24 hours for methods 1 and 3, 12 hours for method 2), a sample of the IVFE was withdrawn from the container using a sterile syringe in an International Organization for Standardization class 5 hood and sent to the hospital microbiology laboratory, where the samples were introduced into blood culture bottles and incubated for five days. Each sample was then subcultured on a blood agar plate with olive oil and left for an additional two days in a carbon dioxide incubator to assess for Malassezia furfur. RESULTS None of the samples from the original containers showed bacterial or fungal growth. Three of the samples from syringes had bacterial growth (two samples contained coagulase-negative staphylococcus and one contained both Klebsiella oxytoca and Citrobacter freundii), yielding a contamination rate of 3.3%. The number of contaminated samples did not significantly differ among the three preparation methods (p = 0.13). CONCLUSION Repackaging IVFE into sterile syringes resulted in bacterial contamination and should be avoided in clinical practice. IVFE samples obtained using the drawdown procedure under sterile conditions for infusion over 24 hours revealed no microbial contamination.

Relative bioavailability of carnitine supplementation in premature neonates

BACKGROUND Carnitine is an important nutrient in the infant diet. We compared total plasma carnitine concentrations in premature neonates supplemented with carnitine via parenteral and enteral nutrition. METHODS This is a post hoc analysis of plasma total carnitine concentrations and carnitine intake in neonates randomized in a previous study to receive 20 mg/kg/d carnitine supplementation over 8 weeks. Neonates received l-carnitine initially via parenteral nutrition (PN). When neonates were fed enterally, oral supplementation of l-carnitine was given in divided doses with each feeding. RESULTS Sixteen neonates (27 +/- 2 weeks gestation; 2.9 +/- 1.0 days postnatal age at enrollment; 965.6 +/- 279.1 g birth weight) are included. Concentrations were below reference range (31.1-60.5 nmol/mL) at baseline and exceeded reference range from week 1 through the last study period. Concentrations were not different from week 1 (108 +/- 49) through weeks 4 (87 +/- 34) and 8 (83 +/- 31). Carnitine intakes and concentrations were compared in neonates receiving 100% parenteral carnitine at week 1 (n = 6) and 100% enteral carnitine at week 8 (n = 8). Concentrations at week 1 (100.1 +/- 27.9) were not different (p = .19) from week 8 (78.6 +/- 29.3); an estimate of relative bioavailability was 78.6%. Bioavailability with paired analysis of neonates (n = 5) receiving 100% parenteral carnitine at week 1 and 100% enteral carnitine at week 8 was 83.7% +/- 41.2% (30.1%-140.6%). CONCLUSIONS Parenteral and enteral supplementation of 20 mg/kg/d carnitine results in plasma total carnitine concentrations that exceed the reference range. Concentrations are not different between parenteral to enteral supplementation, suggesting that enteral carnitine is well absorbed when given daily in divided doses with enteral feedings.

Optimizing the Transition to Home Parenteral Nutrition in Pediatric Patients

Parenteral nutrition (PN) is commonly used in pediatric institutions in patients who either cannot be fed enterally or are unable to tolerate sufficient enteral calories to provide their nutrition requirements. Many pediatric patients, particularly those with short bowel syndrome or intestinal failure, will eventually require home PN (HPN) therapy. Although discharge to HPN is complex and can be associated with both immediate and long-term complications, it can be successfully achieved through collaboration between healthcare providers within the institution and the home care company and HPN education of the patient and caregivers. This review describes the processes that clinicians and institutions should consider when preparing for HPN discharge and serves as a guide for the effective transition to HPN in pediatric patients.

Development of W/O Microemulsion for Transdermal Delivery of Iodide Ions

The objective of this study was to develop a water-in-oil (w/o) microemulsion which can be utilized as a transdermal delivery for iodide ions. Several w/o microemulsion formulations were prepared utilizing Span 20, ethanol, Capryol 90®, and water. The selected formulations had 5%, 10%, 15%, 20%, and a maximum of 23% w/w water content. Potassium iodide (KI) was incorporated in all formulations at 5% w/v. Physicochemical characterizations were conducted to evaluate the structure and stability. These studies included: mean droplet size, pH, viscosity, conductivity, and chemical stability tests. In vitro human skin permeation studies were conducted to evaluate the diffusion of the iodide ion through human skin. The w/o microemulsion formulations were stable and compatible with iodide ions with water content ranging from 5% to 23% w/w. The addition of KI influenced the physicochemical properties of microemulsion as compared to blank microemulsion formulations. In vitro human skin permeation studies indicated that selected formulations improved iodide ion diffusion significantly as compared to control (KI solution; P value < 0.05). Iodide ions were entrapped within the aqueous core of w/o microemulsion. Span 20, ethanol and Capryol 90 protected the iodide ions against oxidation and formed a stable microemulsion. It is worth to note that according to Hofmeister series, iodide ions tend to lower the interfacial tension between water and oil and consequently enhance overall stability. This work illustrates that microemulsion system can be utilized as a vehicle for the transdermal administration of iodide.

Antimicrobial impregnated catheters in the prevention of catheter-related bloodstream infection in hospitalized patients.

Catheter-related bloodstream infections have a significant impact on increasing health care costs and morbidity and mortality in hospitalized patients. Many technologies have been created in an attempt to decrease the incidence of catheter-related bloodstream infection. One of these is the impregnation of central venous catheters with antiseptics (e.g., chlorhexidine and silver sulfadiazine) or antibiotics (e.g., minocycline and rifampin). While studies evaluating the efficacy of impregnated catheters have been conducted, the data are limited and their use remains variable across institutions. This paper will discuss catheter-related factors that predispose patients to catheter-related bloodstream infection, the types of antimicrobial-impregnated catheters in use today, studies evaluating their efficacy, and common concerns associated with the use of these catheters. Issues related to the cost-effectiveness of impregnated catheters and future directions for the prevention of catheter-related bloodstream infection will also be presented.

Significant Publications for Pharmacy Nutrition Support Practice in 2013

Purpose To assist the pharmacy clinician engaged in nutrition support in staying current with the most pertinent literature. Methods Several experienced board-certified clinical pharmacists in nutrition support compiled a list of publications published in 2013 that they considered to be important to their practice. The citation list was compiled into a Web-based survey whereby pharmacist members of the American Society for Parenteral and Enteral Nutrition (A.S.P.E.N.), GI-Liver-Nutrition Practice Research Network of the American College of Clinical Pharmacy, and the Pharmacy and Pharmacology Section of the Society of Critical Care Medicine were asked to rank each article according to level of importance in their practice. Results A total of 30 articles were identified by the author group. Thirty-six participants responded to the survey. The top-ranked papers by participants from the Web-based survey were reviewed by the authors. Due to its high level of importance, the parenteral nutrition safety consensus recommendations article, to be published in 2014 by A.S.P.E.N., was also reviewed. Conclusion It is recommended that the informed pharmacist, who is engaged in nutrition support therapy, be familiar with the majority of these publications.