Advances in Trace Element Supplementation for Parenteral Nutrition

Parenteral nutrition (PN) provides support for patients lacking sufficient intestinal absorption of nutrients. Historically, the need for trace element (TE) supplementation was poorly appreciated, and multi-TE products were not initially subjected to rigorous oversight by the United States Food and Drug Administration (FDA). Subsequently, the American Society for Parenteral and Enteral Nutrition (ASPEN) issued dosage recommendations for PN, which are updated periodically. The FDA has implemented review and approval processes to ensure access to safer and more effective TE products. The development of a multi-TE product meeting ASPEN recommendations and FDA requirements is the result of a partnership between the FDA, industry, and clinicians with expertise in PN. This article examines the rationale for the development of TRALEMENT^® (Trace Elements Injection 4*) and the FDA’s rigorous requirements leading to its review and approval. This combination product contains copper, manganese, selenium, and zinc and is indicated for use in adults and pediatric patients weighing ≥10 kg. Comprehensive management of PN therapy requires consideration of many factors when prescribing, reviewing, preparing, and administering PN, as well as monitoring the nutritional status of patients receiving PN. Understanding patients’ TE requirements and incorporating them into PN is an important part of contemporary PN therapy.

Avoidance of Overt Precipitation and Patient Harm Following Errant Y-Site Administration of Calcium Chloride and Parenteral Nutrition Compounded With Sodium Glycerophosphate

Calcium phosphate precipitates present 1 of many challenges associated with parenteral nutrition (PN) compounding. Extensive research has led to the establishment of solubility curves to guide practitioners in the prescription and preparation of stable PN. Concurrent dosing of intravenous products via y-site administration with PN can alter the chemical balance of the solution and modify solubility. Medications containing calcium or phosphate should not be administered in the same line as PN, due to the high potential for precipitation. Herein a case is reported from a pediatric cardiac intensive care unit where a physician ordered the administration of calcium chloride. The bedside nurse added the calcium chloride intermittent infusion as a y-site administration with the patient's PN. The patient's PN had been compounded with sodium glycerophosphate, temporarily available in the United States during a sodium phosphate shortage. The patient did not experience any observable adverse effects from the y-site administration with PN. Following this event, the scenario was replicated to investigate any precipitation risk associated with the y-site administration. Additionally, a separate PN solution containing sodium phosphate rather than glycerophosphate was compounded and used in a laboratory setting to demonstrate the potential for harm had the patient's PN been compounded with an inorganic phosphate source. This replication of the error demonstrates the additional safety gained in relation to precipitation risk when PN solutions are compounded with sodium glycerophosphate in place of sodium phosphate.

Calcium and Phosphorous in Pediatric Parenteral Nutrition

Calcium (Ca) and phosphorus (P) are essential for various systemic functions, including bone mineralization. Adequate provision of Ca and P in pediatric parenteral nutrition (PN) solutions is necessary for skeletal growth and for the prevention of metabolic bone disease. The provision of adequate doses of Ca and P in pediatric PN solutions is complicated by the increased needs in preterm and term infants, solubility limitations, and venous access. Clinicians should be aware of the evidence that supports the optimal use of Ca and P in pediatric PN solutions, including studies that have evaluated dosing and solubility. The aim of this article is to review relevant literature and practices for the use of these two minerals in pediatric PN solutions. The vitamin D endocrine system, a critical component for Ca homeostasis and bone mineralization, is discussed, as well as clinical manifestations of metabolic bone disease and methods for its prevention, assessment, and treatment in pediatric patients receiving PN.

In Vitro Assessment of Interaction Between Amino Acids and Copper in Neonatal Parenteral Nutrition

BACKGROUND

The repeated blackening of in-line filters has been observed during the infusion of parenteral nutrition 2-in-1 mixtures (binary parenteral nutrition [BPN]) delivered in a neonatal intensive care unit. This study aimed to examine the elemental content of precipitates isolated from infused BPN bags and determine the main physicochemical interactions occurring in these bags.

MATERIALS AND METHODS

The infusion of BPN mixtures was simulated in vitro following hospital practices. Filter membranes were examined by scanning electron microscopy and energy dispersion spectroscopy (EDS). Amino acid (AA) profiles were obtained from BPN mixtures to determine the concentrations of each AA.

RESULTS

Analyzed filter membranes revealed conglomerates of particles on filter surfaces. An EDS analysis generated spectra from isolated particles, identifying copper and sulfur as the major chemical elements. AA mean concentrations were relatively close to the expected value for each AA, except cysteine. Cysteine concentrations were very significantly lower than the expected values.

CONCLUSION

A specific interaction was identified between 1 AA (cysteine) and a trace element (copper) in our BPN mixtures.

History of sterile compounding in U.S. hospitals: learning from the tragic lessons of the past

PURPOSE

The evolution of sterile compounding in the context of hospital patient care, the evolution of related technology, past incidents of morbidity and mortality associated with preparations compounded in various settings, and efforts over the years to improve compounding practices are reviewed.

SUMMARY

Tightened United States Pharmacopeial Convention standards (since 2004) for sterile compounding made it difficult for hospitals to achieve all of the sterile compounding necessary for patient care. Shortages of manufactured injections added to the need for compounding. Non-hospital-based compounding pharmacies increased sterile compounding to meet the needs. Gaps in federal and state laws and regulations about compounding pharmacies led to deficiencies in their regulation. Lapses in sterility led to injuries and deaths. Perspectives offered include potential actions, including changes in practitioner education, better surveillance of sterile compounding, regulatory reforms, reexamination of the causes of drug shortages, and the development of new technologies.

CONCLUSION

Over the years, there have been numerous exhortations for voluntary better performance in sterile compounding. In addition, professional leadership has been vigorous and extensive in the form of guidance, publications, education, enforceable standards, and development of various associations and organizations dealing with safe compounding practices. Yet problems continue to occur. We must engage in diligent learning from the injuries and tragedies that have occurred. Assuming that we are already doing all we can to avoid problems would be an abdication of the professional mission of pharmacists. It would be wrong thinking to assume that the recent problems in large-scale compounding pharmacies are the only problems that warrant attention. It is time for a systematic assessment of the nature and the dimensions of the problems in every type of setting where sterile compounding occurs. It also is time for some innovative thinking about ensuring safety in sterile compounding.

A.S.P.E.N. position paper: recommendations for changes in commercially available parenteral multivitamin and multi-trace element products

The parenteral multivitamin preparations that are commercially available in the United States (U.S.) meet the requirements for most patients who receive parenteral nutrition (PN). However, a separate parenteral vitamin D preparation (cholecalciferol or ergocalciferol) should be made available for treatment of patients with vitamin D deficiency unresponsive to oral vitamin D supplementation. Carnitine is commercially available and should be routinely added to neonatal PN formulations. Choline should also be routinely added to adult and pediatric PN formulations; however, a commercially available parenteral product needs to be developed. The parenteral multi-trace element (TE) preparations that are commercially available in the U.S. require significant modifications. Single-entity trace element products can be used to meet individual patient needs when the multiple-element products are inappropriate (see Summary/A.S.P.E.N. Recommendations section for details of these proposed modifications).

Dosing and monitoring of trace elements in long-term home parenteral nutrition patients

BACKGROUND

Trace elements (TEs) dosing and monitoring in home parenteral nutrition (PN) patients vary with their underlying conditions.

METHODS

This retrospective observational study evaluated parenteral TE dosing, serum TE concentrations and monitoring, and dose-concentration relationships between TE doses and serum TE concentrations in 26 adult and adolescent home PN patients.

RESULTS

There was a total of 40,493 PN days. Average parenteral zinc doses of 9.1 mg/d and 7.6 mg/d resulted in the majority of serum zinc concentrations (90%) within normal range in patients with and without short bowel syndrome (SBS), respectively. Selenium at about 70 mcg/d resulted in about 60% of serum selenium concentrations within normal range, with 38% of values below normal in patients with and without SBS alike. Copper at 1 mg/d resulted in 22.5% of serum copper concentrations above the normal range. The majority of serum manganese (94.6%) and chromium (96%) concentrations were elevated. Serum TE concentrations were infrequently monitored. Significant relationships existed between doses and serum concentrations for zinc (P < .0001), manganese (P = .012), and chromium (P < .0001) but not for selenium or copper.

CONCLUSIONS

TE doses in home PN should be individualized and adjusted based on regular monitoring of TE status. In long-term home PN patients, higher zinc and selenium doses may be necessary to maintain their normal serum concentrations. Lower copper doses and restrictions of manganese and chromium supplementation may be needed to avoid their accumulation. Relationships between TE doses and serum TE concentrations vary for each TE and underlying clinical conditions.

State of the art review: Intravenous fat emulsions: Current applications, safety profile, and clinical implications

OBJECTIVE

To review the current state of the science regarding intravenous fat emulsions (IVFEs), with an emphasis on their safety profile.

DATA SOURCES

Articles were identified via a search of the MEDLINE database, including publications from 1979 to December 2009, using a search string that included the terms parenteral nutrition, lipid emulsion, fat emulsion, IVFE, safety, adverse effect, neonate intralipid, and terms describing a range of specific adverse events (AEs) such as pancreatitis.

STUDY SELECTION AND DATA EXTRACTION

We selected articles that allowed us to compare the results of clinical trials involving delivery of medications via IVFEs with the historical use and effects of IVFEs in parenteral nutrition, with an emphasis on AEs. We focused on 2 drugs in current use that are administered intravenously in lipid emulsions: propofol and clevidipine.

DATA SYNTHESIS

Clearance of the fat particles in IVFEs is mediated by the enzyme lipoprotein lipase. AEs are more likely if the rate or duration of IVFE administration exceeds the enzyme's clearance capacity. AEs are also more likely after administration of a 10% IVFE formulation than a 20% formulation, because the higher concentration of free phospholipid in the 10% formulation interferes with lipoprotein lipase activity. AEs can be reduced by administering IVFEs at a dosage < or = 2.5 g/kg/day and at a rate < or = 0.11 g/kg/h. The anesthetic agent propofol, which is formulated in a 10% IVFE, has been used clinically for 25 years. Typical AEs associated with propofol use include infection, high plasma triglyceride concentrations, and pancreatitis. Recent clinical trials involving clevidipine, which is formulated in a 20% IVFE, have demonstrated a low rate of lipid-related AEs.

CONCLUSIONS

The results of this review demonstrate that IVFEs are well tolerated when administered in accordance with guideline recommendations.

Zinc supplementation in critically ill patients: a key pharmaconutrient?

The purpose of the present paper is to provide a rationale for zinc supplementation as a potential therapeutic agent in critically ill patients by describing its role in health and disease, conducting a systematic review of current randomized trials in critical care, considering optimum route and dose of administration, and making recommendations for future research. Normal zinc homeostasis is required for a functional immune system, adequate antioxidant capacity, glucose homeostasis, and wound healing. In addition, zinc is a required cofactor for many enzymes, transcription factors, and replication factors. In non-critically ill patients, zinc supplementation has been associated with an improvement in markers of immune function. In critically ill patients, only 4 randomized trials have examined the effect of zinc supplementation on clinical outcomes. When all 4 studies were aggregated, zinc supplementation was associated with a nonsignificant reduction in mortality (relative risk = 0.63, 95% confidence intervals 0.25-1.59, P = .33) and length of stay in intensive care (-0.35 days, -0.85 to 0.15; P = .17). Thus, because of the paucity of clinical data, there is inadequate evidence to recommend the routine use of high-dose zinc supplementation in the critically ill. A first step would be to determine the optimal dose that has a maximal positive effect on underlying inflammatory, immunologic, and metabolic processes yet is safe and tolerated by critically ill patients. Subsequently, large, rigorously designed, randomized trials are required to elucidate the efficacy of such doses of zinc supplementation in this patient population.

Trace element loss in urine and effluent following traumatic injury

BACKGROUND

Few data are available to establish recommendations for trace element supplementation during critical illness. This study quantified the loss of several elements and assessed the adequacy of manganese and selenium in parenteral nutrition (PN).

METHODS

Men with traumatic injuries were grouped by renal status: adequate (POLY; n = 6), acute failure with continuous venovenous hemofiltration (CVVH; n = 2), or continuous venovenous hemodiafiltration (CVVHD; n = 4). PN supplied 300 microg/d manganese and 60 microg/d selenium. Urine and effluent (from artificial kidneys) were collected for 3 days and analyzed for boron, manganese, nickel, and silicon using inductively coupled plasma atomic emission spectrometry, and for selenium using atomic absorption spectrometry.

RESULTS

POLY manganese and selenium excretion averaged (standard deviation [SD]) 7.9 (3.3) microg/d and 103.5 (22.4) microg/d, respectively. All elements except selenium were detected in dialysate (prior to use). CVVHD effluent contained 3.5 and 7.3 times more manganese and nickel than CVVH ultrafiltrate, respectively. Loss of manganese averaged 2.6%, 21%, and 73% of PN amounts for POLY, CVVH, and CVVHD groups, respectively.

DISCUSSION

Minimal loss of manganese compared with the amount in PN suggests that excessive amounts are retained. POLY patients excreted more selenium than was in PN, indicating negative balance. POLY losses of boron and silicon were less than that published for healthy adults, reflecting less than typical intake, whereas loss during CVVH was in the normal reference range, possibly because of added intake from boron contamination of replacement fluids. All patients lost more nickel than amounts published for healthy adults.

CONCLUSIONS

Current guidelines of 60-100 microg/d of parenteral manganese may be excessive for trauma patients. The uptake of manganese and nickel from contaminants in CVVHD dialysate should be investigated.

Autopsy tissue trace elements in 8 long-term parenteral nutrition patients who received the current U.S. Food and Drug Administration formulation

Iron, zinc, copper, manganese, chromium, and selenium levels were measured in autopsy tissues of 8 people with short bowel syndrome who received home parenteral nutrition (HPN) and the U.S. Food and Drug Administration (FDA)-approved trace element formulation for an average duration of 14 years (range, 2-21). Iron, zinc, copper, manganese and selenium were measured by inductively coupled plasma methods; chromium, by graphite furnace atomic absorption spectrometry. The levels in the 4 tissues studied, heart, skeletal muscle, liver, and kidney, were compared with levels in 45 controls who died without chronic gastrointestinal disorders. Results showed normal HPN patient values for iron and selenium, mild elevation of zinc, and major elevations of copper, manganese, and chromium. The implications of these results for trace-element supplements in long-term PN adult patients are discussed, and the need for reformulation of commercially available multi-trace element products in the United States is stressed.

Parenteral Nutrition Safe Practices: Results of the 2003 American Society for Parenteral and Enteral Nutrition Survey*

BACKGROUND

The American Society for Parenteral and Enteral Nutrition (A.S.P.E.N.) recently published a revision of its "Safe Practices for Parenteral Nutrition" guidelines. Because there is a paucity of published scientific evidence to support good practices related to ordering, compounding, and administering parenteral nutrition (PN), a survey was performed in the process of the revision to gain insight into the discrepancies between reported practices and previous guidelines.

METHODS

A web-based survey consisting of 45 questions was conducted (n = 651) June 1-30, 2003. Respondents were queried about primary practice setting, professional background, processes for writing PN orders, computer order entry of PN orders, problems with PN orders, and adverse events related to PN.

RESULTS

There were 651 survey responses, 90% of which were from hospital-based practitioners. Almost 75% of responders processed between 0 and 20 PN orders per day. Overall, physicians (78%) were responsible for writing PN orders, but dietitians and pharmacists had significant involvement. PN base components were most often ordered as percentage final concentration after admixture (eg, 20% dextrose), which is inconsistent with safe practice guidelines of ordering by total amount per day (eg, 200 g/day). There was no consistent method for ordering PN electrolytes. Approximately 45% of responders reported adverse events directly related to PN that required intervention. Of these events, 25% caused temporary or permanent harm, and 4.8% resulted in a near-death event or death.

CONCLUSIONS

Although the survey found consistency in PN practices for many areas queried, significant variation exists in the manner by which PN is ordered and labeled.

Assessment of ascorbic acid stability in different multilayered parenteral nutrition bags: critical influence of the bag wall material

BACKGROUND

The recent development of multilayered bags has minimized ascorbic acid oxidation in parenteral nutrition (PN) admixtures. However, the gas-barrier property of multilayered bags depends on their plastic material. This study compared ascorbic acid stability in different multilayered bags under experimental conditions.

METHODS

Oxygen permeability of a newly developed 6-layered bag (6-L) was compared with a highly mechanical-resistant 3-layered bag (3-L(R)) and a highly flexible 3-layered bag (3-L(F)) using gas chromatography. Ascorbic acid stability was assessed by iodine titration in bags filled with 2.5 L H(2)O and 40 g carbohydrates after setting residual O(2) content at < or =1 or > or =5 ppm. The effect of storage at 4 degrees C, 21 degrees C, and 40 degrees C on ascorbic acid stability was assessed over 48 hours in a complete PN admixture (ie, 330 g carbohydrates, 100 g lipids, 96 g amino acids and trace elements) using high-pressure liquid chromatography.

RESULTS

Oxygen permeability was markedly reduced in 6-L bags (0.5 mL O(2) /m(2)/d) compared with 3-L(R) (150 mL O(2) /m(2)/d) and 3-L(R) (1500 mL O(2)/m(2)/d). Accordingly, ascorbic acid was more stable in 6-L bags (half-life [T(1/2)] = 16 days up to 40 degrees C) than in 3-L(R) (T(1/2) = 9 days at 4 degrees C, 47 hours at 21 degrees C and 29 hours at 40 degrees C) and 3-L(F) (T(1/2) = 15 hours at 4 degrees C, 10 hours at 21 degrees C, and 6 hours at 40 degrees C). During the first 6 hours after PN admixture compounding, an additive ascorbic acid loss of 4.6 +/- 0.5 mg/L/ppm O(2) occurred because of residual O(2) in the bag.

CONCLUSIONS

The new combination of plastic layers and careful O(2) monitoring during the filling process allowed near to complete prevention of ascorbic acid degradation in multilayered PN bags during 48 hours, regardless of the storage temperature.

Inhibitory Effects of Amino-Acid Fluids on Drug Binding to Site II of Human Serum Albumin in Vitro

The effects of amino-acid fluids on ligand binding to human serum albumin (HSA) were investigated by fluorescence and ultrafiltration techniques. Warfarin and dansylsarcosine were used as the site marker fluorescence probes for site I and site II of HSA, respectively. Amino-acid fluids specifically decreased the fluorescence intensity induced by dansylsarcosine-HSA binding without any effects on that induced by warfarin-HSA binding. The ultrafiltration technique clarified that the free fraction of the site II drug, diazepam, in human serum was increased in the presence of amino-acid fluids, while no effect was observed in the free fraction of the site I drug, warfarin. The potencies of the effect on binding to site II, observed by fluorescence and ultrafiltration techniques, correlated well with the L-tryptophan contents in amino-acid fluids or with those in L-tryptophan solutions. Based on the comparison between the effects of amino-acid fluids and L-tryptophan solutions, we confirmed that L-tryptophan in amino-acid fluids specifically inhibits drug binding to site II of HSA.

Effect of 24-Hour Intravenous Tubing Set Change on the Sterility of Repackaged Fat Emulsion in Neonates

BACKGROUND

Duration of intravenous fat emulsion (IVFE) infusions, precise method of administration (manufactured bottle vs repackaged syringe), and interval for administration set change continue to be debated.

OBJECTIVE

To determine the contamination rate associated with replacing IVFE administration sets every 24 hours in newborn infants receiving fat emulsion repackaged into unit-of-use syringes.

METHODS

This was a prospective, microbiologic study of 90 administration sets used in 19 neonates. IVFE samples were obtained from administration sets at the end of a 19– to 23–hour infusion and prior to daily tubing set change from infants who received repackaged IVFE. Samples of IVFE (1–3 mL) were aseptically removed at the catheter connection site proximal to the patient, transferred into BACTEC PEDSPlus culture media, and continuously monitored for 5 days to detect gram-positive and gram-negative organisms, as well as yeast.

RESULTS

Two samples (2.27%) grew coagulase-negative Staphylococcus. Both samples were from the same asymptomatic patient and were obtained on consecutive days. A blood sample obtained through this infant's central catheter grew the same organism and suggested catheter hub colonization as the primary site of microbe origin.

CONCLUSIONS

Microbial contamination of IVFE infusion sets changed at 24–hour intervals, using unit-of-use syringes in neonates, was low at 2.2%.

Hypophosphatemia after 95 right-lobe living-donor hepatectomies for liver transplantation is not a significant source of morbidity

BACKGROUND

Hypophosphatemia appears to be a universal event after right hepatic lobectomy for live-donor adult liver transplantation according to one report. Because hypophosphatemia appears to contribute to increased postoperative complications, routine hyperalimentation with supratherapeutic levels of phosphorus was advocated.

METHODS

From July 2000 to May 2002, we performed 95 right-lobe living-donor hepatectomies for 95 adult liver-transplant recipients, the largest single institutional experience. We reviewed our data that were collected prospectively.

RESULTS

We did not find profound hypophosphatemia (<1.0 mg/dL) to be prevalent in our donors. At least six (6.3%) donors did not have postoperative hypophosphatemia. In addition, there appears to be no increased morbidity related to hypophosphatemia when aggressively corrected with intravenous or oral phosphates in our group of donors that underwent right-lobe hepatectomies.

CONCLUSIONS

We, therefore, cannot endorse the routine administration of hyperalimentation with supratherapeutic phosphorus because of its potential morbidity.

Peripheral parenteral nutrition

BACKGROUND

Peripheral parenteral nutrition (PPN) currently accounts for almost 20 per cent of all parenteral nutrition administered in the UK. In the absence of consensus guidelines there is wide variation in practice. Heterogeneity of clinical trials has made direct comparisons difficult and meta-analysis impossible.

METHODS

Medline, Embase and Cochrane databases were searched for all clinical trials relating to the use of PPN in adults. Relevant papers from the reference lists of these articles and from the authors' personal collections were also reviewed.

RESULTS AND CONCLUSIONS

Effective PPN is possible in about 50 per cent of inpatients requiring parenteral nutrition. Evidence relating to optimal feed composition, choice of cannula, infusion technique and pharmacological manipulation is discussed, along with practical recommendations for the administration of PPN.

Whole-blood manganese levels and brain manganese accumulation in children receiving long-term home parenteral nutrition

Recent reports attribute neurological and cerebral disorders to the accumulation of manganese (Mn) in the brain in patients receiving home parenteral nutrition (HPN). It is desirable to control the amount of Mn delivered to these patients, but a suitable method for monitoring an individual's Mn status and assessing Mn accumulation remains debatable. The aim of this study was to evaluate whether whole-blood manganese levels (WB-Mn) correlate with the accumulation of Mn in the brains of children who receive long-term HPN, using magnetic resonance imaging (MRI) of the brain. Six patients who had received HPN (duration of HPN, 18-137 months) were included in this study. The daily parenteral doses of Mn were calculated while on HPN. WB-Mn was measured and T1-weighted MRI of the brain was obtained for each patient with a 1.5-T MR imager. Twelve months after the withdrawal of Mn from HPN, measurements of WB-Mn and brain MRI were repeated in all patients except for one who was lost after initial examination. The same examinations were performed on an additional patient who had been successfully weaned off a 179 month course of HPN 20 months prior to the initial examination. The parenteral dose of Mn while receiving HPN ranged from 15.7 to 91.5 micro g/kg/day. Initially, MRI showed hyperintensity in the globus pallidus in all patients and in the anterior pituitary in one patient. WB-Mn was elevated in four patients, but was in the normal range in the remaining three. Following subsequent measurements 12 months later, WB-Mn was normal in all patients and MRI hyperintensity remained in the globus pallidus in one patient. One patient was lost after the initial examinations. WB-Mn does not necessarily correlate with the accumulation of Mn in the brain. Periodic MRI should be performed in patients receiving long-term NPN to monitor for excessive Mn accumulation in the brain.

Early enteral immunonutrition in patients with severe sepsis: results of an interim analysis of a randomized multicentre clinical trial

OBJECTIVE

To compare the mortality of critically ill patients given either enteral feeding with an immune-enhancing formula or parenteral nutrition (PN). We report the results of a planned interim analysis on patients with severe sepsis which was undertaken earlier than planned once a meta-analysis suggested excess mortality in patients with severe sepsis given enteral immunonutrition.

DESIGN

Randomised multicentre unblinded controlled clinical trial.

SETTING

Thirty-three General Intensive Care Units in Italy.

PATIENTS AND PARTICIPANTS

Among the 237 recruited patients, 39 had severe sepsis or septic shock; 21 of them received PN.

INTERVENTIONS

Eligible patients received either total PN or enteral nutrition, the latter containing extra L-arginine, omega-3 fatty acids, vitamin E, beta carotene, zinc, and selenium.

MEASUREMENTS AND RESULTS

The primary endpoint for the subgroup analysis on patients with severe sepsis was mortality on Intensive Care Unit (ICU). The ICU mortality of patients with severe sepsis given enteral nutrition (EN) was higher than for those given PN (44.4% vs 14.3%; p=0.039). More patients given EN than patients given PN still had severe sepsis when they died (38.9% vs 9.5%, p=0.055). Recruitment of patients with severe sepsis was subsequently stopped.

CONCLUSIONS

Our results show that enteral immunonutrition, compared to PN, may be associated with excess mortality in patients with severe sepsis.

The branched-chain amino acid requirement of parenterally fed neonatal piglets is less than the enteral requirement

The requirements for branched-chain amino acids (BCAA), isoleucine, leucine and valine, in neonates have not been determined previously. Furthermore, the BCAA are considered to be catabolized primarily in the muscle and their metabolism in the small intestine has received little attention. In this study, the parenteral and enteral BCAA requirements were determined by the indicator amino acid oxidation (IAAO) technique. Male Yorkshire piglets (n = 32) received amino acid-based diets containing adequate nutrients for 5 d. On d 6 and 8, the piglets were randomly assigned to one of the test diets containing a fixed ratio of BCAA (1:1.8:1.2; isoleucine/leucine/valine). Diets were infused continuously via intravenous catheters for parenterally fed piglets or via gastric catheters for enterally fed piglets. Phenylalanine kinetics and oxidation were determined from a 4-h primed, constant infusion of L-[1-(14)C]phenylalanine. Phenylalanine oxidation (% of dose) decreased linearly (P < 0.05) as the BCAA intake increased from 0.2 to 1.53 g/(kg. d) and from 0.2 to 2.64 g/(kg. d) for parenterally and enterally fed piglets, respectively, after which the phenylalanine oxidation was low and the slope was not different from zero. Using breakpoint analysis, the mean total BCAA requirements were determined to be 1.53 and 2.64 g/(kg. d) for parenterally and enterally fed piglets, respectively. Thus, the parenteral requirement for total BCAA is 56% of the enteral requirement, suggesting that 44% of total BCAA is extracted by first-pass splanchnic metabolism.

Parenteral nutrition-associated liver complications in children

Parenteral nutrition is a life-saving therapy for patients with intestinal failure. It may be associated with transient elevations of liver enzyme concentrations, which return to normal after parenteral nutrition is discontinued. Prolonged parenteral nutrition is associated with complications affecting the hepatobiliary system, such as cholelithiasis, cholestasis, and steatosis. The most common of these is parenteral nutrition-associated cholestasis (PNAC), which may occur in children and may progress to liver failure. The pathophysiology of PNAC is poorly understood, and the etiology is multifactorial. Risk factors include prematurity, long duration of parenteral nutrition, sepsis, lack of bowel motility, and short bowel syndrome. Possible etiologies include excessive caloric administration, parenteral nutrition components, and nutritional deficiencies. Several measures can be undertaken to prevent PNAC, such as avoiding overfeeding, providing a balanced source of energy, weaning parenteral nutrition, starting enteral feeding, and avoiding sepsis.

Evaluation of indexes of in vivo manganese status and the optimal intravenous dose for adult patients undergoing home parenteral nutrition

BACKGROUND

There are no accurate indexes for determining the status of manganese in humans, and there is no clear recommended daily dose of this essential trace element to be administered in total parenteral nutrition solutions.

OBJECTIVE

The objectives were to evaluate accurate indexes of manganese status and elucidate the optimal manganese dose to be administered to adult patients undergoing home parenteral nutrition.

DESIGN

Patients were administered total parenteral nutrition solutions providing 0, 1, 2, or 20 micromol Mn/d according to an on-off design, after which manganese concentrations in whole blood and plasma were determined. Magnetic resonance imaging (MRI) was performed to determine the intensity on T(1)-weighted images (MRI intensity) and T(1) values in the globus pallidus. Hematologic and biochemistry tests were also performed.

RESULTS

High degrees of correlation were found between whole-blood manganese concentrations and both MRI intensity (r = 0.7728) and T(1) values (r = -0.7519) in the globus pallidus. A strong negative correlation was found between MRI intensity and T(1) values (r = -0.8407). The dose of 1 micromol Mn/d caused no change in MRI intensity or T(1) values, and the whole-blood manganese concentration remained within the normal range in all patients.

CONCLUSIONS

Whole-blood manganese concentrations and MRI intensity and T(1) values in the globus pallidus are useful indexes of the status of manganese in humans. The optimal dose of manganese may be 1 micromol/d for adult patients undergoing home parenteral nutrition.

Prospective survey of parenteral nutrition in Switzerland: a three-year nation-wide survey

BACKGROUND AND AIMS

The goals of this national survey were to determine the current PN practices and admixture formulations used in Switzerland.

METHODS

During three years, an annual questionnaire was sent to all heads of Swiss hospital pharmacies.

RESULTS

92% of Swiss hospitals with a full-time pharmacist participated. Different PN systems were commonly used for adult patients: 2 commercial formulas in 2 or 3 compartments bags, 2 commercial formulas with/without lipid, 3 formulas compounded by the hospital pharmacy. For hospitalized adults, 83% of PN bags were administered as commercial multicompartment bags. The compounding of individualized PN admixtures takes place primarily in pharmacies of medium to large size hospitals. For pediatric PN, hospital compounding is routine because of individualized PN compositions and absence of commercially available standardized admixtures. Long-term home-PN was mostly delivered by hospital pharmacies (57%) or by private nutrition support home delivery services (37%). Most PN formula compositions complied with European guidelines and represented 2.6+/-2.0% of the hospital drug budget. Multi-disciplinary nutritional support teams were present in 52% of hospitals.

CONCLUSION

In Switzerland, most PN for hospitalized adults were administered as commercial multi-compartment bags. The compounding of individualized PN admixtures were still important for pediatric patients and long-term home-PN.

Quality improvement in parenteral nutrition care

The therapeutic objective of parenteral nutrition, as well as any other pharmacological treatment, must be organized for and focused on the patient, to obtain outcomes associated with an improvement in health status and quality of life. On this basis, the present article starts with a view of quality improvement in health care, identifying the structure, process and outcome paradigm for drug therapy and parenteral nutrition elements of quality assessment, as well as strategies for quality improvement will be described. A model of the organization assigned to parenteral nutrition care is proposed. In the future, computerized programs of parenteral nutrition may increase the risk of uncoordinated and fragmented care. The programs must improve health care of patient by exposing caregivers to the full alternatives of decisions with clinical and therapeutic data on patient individual.

Parenteral nutrition for the acutely ill

Parenteral nutrition (PN) is one of the most sophisticated forms of intravenous therapy in use today. Intravenous feeding is a life-saving technology for patients unable to maintain their nutritional status using the gastrointestinal tract. Although PN has become an integral component of patient care, the risks associated with this therapy must be weighed against the potential benefits. Comprehensive clinical management includes selection of candidates, implementation and monitoring of therapy, and ensuring a seamless transition when PN is no longer required. Optimal parenteral nutrition demands expertise in caring for vascular access devices. A collaborative approach to care minimizes the risks associated with PN and ensures positive patient outcomes.

The diverse role of selenium within selenoproteins: a review

Selenium functions within mammalian systems primarily in the form of selenoproteins. Selenoproteins contain selenium as selenocysteine and perform a variety of physiological roles. Eleven selenoproteins have been identified: cellular or classical glutathione peroxidase; plasma (or extracellular) glutathione peroxidase; phospholipid hydroperoxide glutathione peroxidase; gastrointestinal glutathione peroxidase; selenoprotein P; types 1, 2, and 3 iodothyronine deiodinase; selenoprotein W; thioredoxin reductase; and selenophosphate synthetase. Of these, cellular and plasma glutathione peroxidase are the functional parameters used for the assessment of selenium status. Glutathione peroxidases catalyze the reduction of peroxides that can cause cellular damage. Thioredoxin reductase provides reducing power for several biochemical processes and defends against oxidative stress. Selenoprotein P appears to play a role in oxidant defense. Selenoprotein W may play a role in oxidant defense and be involved with muscle metabolism. Thyroid deiodinases function in the formation and regulation of active thyroid hormone. Selenophosphate synthetase is an enzyme required for the incorporation of selenocysteine into selenoproteins. In addition, a protein in the sperm mitochondrial capsule, which is vital to the integrity of sperm flagella, may be a unique selenoprotein. Recommended intakes, food sources, and status assessment of selenium, as well as selenium's role in health and disease processes, are reviewed.

Clinical Management of the Adult Home Nutrition Support Patient

Nutrition Support Consultant features issues pertinent to the clinical aspects of pharmacy nutritional support practice. The column is edited by Roland N. Dickerson, PharmD, BCNSP, CNS, FACN, Associate Professor of Clinical Pharmacy, University of Tennessee, Memphis.

Trace element deficiency and toxicity

Trace elements are involved in enzymatic activities, immunological reactions, physiological mechanisms and carcinogenesis. Deficiency in some trace elements, such as iron and iodine, is still an important health problem, especially in developing countries. Some groups of individuals are more likely to develop trace element deficiency. The role of trace elements deficiency is suspected in various clinical situations and is now confirmed by well designed supplementation studies. Although toxicity of trace elements with clinical manifestations is rare, it has been observed that manganese toxicity may occur in patients receiving parenteral nutrition. Recent data about trace elements deficiency and toxicity are indicated in this review.