Supplementation of trace elements in parenteral nutrition: Rationale and recommendations

Parenteral Nutrition and Oxidant Load in Neonates

Neonates with preterm, gastrointestinal dysfunction and very low birth weights are often intolerant to oral feeding. In such infants, the provision of nutrients via parenteral nutrition (PN) becomes necessary for short-term survival, as well as long-term health. However, the elemental nutrients in PN can be a major source of oxidants due to interactions between nutrients, imbalances of anti- and pro-oxidants, and environmental conditions. Moreover, neonates fed PN are at greater risk of oxidative stress, not only from dietary sources, but also because of immature antioxidant defences. Various interventions can lower the oxidant load in PN, including the supplementation of PN with antioxidant vitamins, glutathione, additional arginine and additional cysteine; reduced levels of pro-oxidant nutrients such as iron; protection from light and oxygen; and proper storage temperature. This narrative review of published data provides insight to oxidant molecules generated in PN, nutrient sources of oxidants, and measures to minimize oxidant levels.

The Role of Fe, Zn, and Cu in Pregnancy

Iron (Fe), copper (Cu), and zinc (Zn) are microelements essential for the proper functioning of living organisms. These elements participatein many processes, including cellular metabolism and antioxidant and anti-inflammatory defenses, and also influence enzyme activity, regulate gene expression, and take part in protein synthesis. Fe, Cu, and Zn have a significant impact on the health of pregnant women and in the development of the fetus, as well as on the health of the newborn. A proper concentration of these elements in the body of women during pregnancy reduces the risk of complications such as anemia, induced hypertension, low birth weight, preeclampsia, and postnatal complications. The interactions between Fe, Cu, and Zn influence their availability due to their similar physicochemical properties. This most often occurs during intestinal absorption, where metal ions compete for binding sites with transport compounds. Additionally, the relationships between these ions have a great influence on the course of reactions in the tissues, as well as on their excretion, which can be stimulated or delayed. This review aims to summarize reports on the influence of Fe, Cu, and Zn on the course of single and multiple pregnancies, and to discuss the interdependencies and mechanisms occurring between Fe, Cu, and Zn.

A Mnemonic for Pharmacists to Ensure Optimal Monitoring and Safety of Total Parenteral Nutrition: I AM FULL

Objective: To present a guideline-derived mnemonic that provides a systematic monitoring process to increase pharmacists’ confidence in total parenteral nutrition (TPN) monitoring and improve safety and efficacy of TPN use. Data Sources: The American Society for Parenteral and Enteral Nutrition (ASPEN) guidelines were reviewed. Additional resources included a literature search of PubMed (1980 to May 2016) using the search terms: total parenteral nutrition, mnemonic, indications, allergy, macronutrients, micronutrients, fluid, comorbidities, labs, peripheral line, and central line. Articles (English-language only) were evaluated for content, and additional references were identified from a review of literature citations. Study Selection and Data Extraction: All English-language observational studies, review articles, meta-analyses, guidelines, and randomized trials assessing monitoring parameters of TPN were evaluated. Data Synthesis: The ASPEN guidelines were referenced to develop key components of the mnemonic. Review articles, observational trials, meta-analyses, and randomized trials were reviewed in cases where guidelines did not adequately address these components. Conclusions: A guideline-derived mnemonic was developed to systematically and safely manage TPN therapy. The mnemonic combines 7 essential components of TPN use and monitoring: Indications, Allergies, Macro/Micro nutrients, Fluid, Underlying comorbidities, Labs, and Line type.

Trace Elements in Parenteral Nutrition: Considerations for the Prescribing Clinician

Trace elements (TEs) are an essential component of parenteral nutrition (PN). Over the last few decades, there has been increased experience with PN, and with this knowledge more information about the management of trace elements has become available. There is increasing awareness of the effects of deficiencies and toxicities of certain trace elements. Despite this heightened awareness, much is still unknown in terms of trace element monitoring, the accuracy of different assays, and current TE contamination of solutions. The supplementation of TEs is a complex and important part of the PN prescription. Understanding the role of different disease states and the need for reduced or increased doses is essential. Given the heterogeneity of the PN patients, supplementation should be individualized.

Micronutrient Assessment in Long-Term Home Parenteral Nutrition Patients

Assessment of micronutrient status of patients requiring long-term parenteral nutrition (PN) continues to be a challenge for clinicians. The scientific literature primarily consists of small studies and case reports. There are no evidence-based guidelines available. Clinicians rely on clinical assessment according to the patient's disease process, medication regimen, physical examination, and history of nutrient intake to determine existence or risk of micronutrient deficiency and toxicity. This paper will examine current scientific evidence and existing recommendations for the micronutrient assessment and management of patients requiring long-term PN.

Manganese Is Essential for Neuronal Health

The understanding of manganese (Mn) biology, in particular its cellular regulation and role in neurological disease, is an area of expanding interest. Mn is an essential micronutrient that is required for the activity of a diverse set of enzymatic proteins (e.g., arginase and glutamine synthase). Although necessary for life, Mn is toxic in excess. Thus, maintaining appropriate levels of intracellular Mn is critical. Unlike other essential metals, cell-level homeostatic mechanisms of Mn have not been identified. In this review, we discuss common forms of Mn exposure, absorption, and transport via regulated uptake/exchange at the gut and blood-brain barrier and via biliary excretion. We present the current understanding of cellular uptake and efflux as well as subcellular storage and transport of Mn. In addition, we highlight the Mn-dependent and Mn-responsive pathways implicated in the growing evidence of its role in Parkinson's disease and Huntington's disease. We conclude with suggestions for future focuses of Mn health-related research.

Manganese in human parenteral nutrition: considerations for toxicity and biomonitoring

The iatrogenic risks associated with excessive Mn administration in parenteral nutrition (PN) patients are well documented. Hypermanganesemia and neurotoxicity are associated with the duration of Mn supplementation, Mn dosage, as well as pathological conditions, such as anemia or cholestasis. Recent PN guidelines recommend the biomonitoring of patients if they receive Mn in their PN longer than 30 days. The data in the literature are conflicting about the method for assessing Mn stores in humans as a definitive biomarker of Mn exposure or induced-neurotoxicity has yet to be identified. The biomonitoring of Mn relies on the analysis of whole blood Mn (WB Mn) levels, which are highly variable among human population and are not strictly correlated with Mn-induced neurotoxicity. Alterations in dopaminergic (DAergic) and catecholaminergic metabolism have been studied as predictive biomarkers of Mn-induced neurotoxicity. Given these limitations, this review addresses various approaches for biomonitoring Mn exposure and neurotoxic risk.

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.

Cloud point extraction of vanadium in pharmaceutical formulations, dialysate and parenteral solutions using 8-hydroxyquinoline and nonionic surfactant

A cloud point extraction (CPE) method has been developed for the determination of trace quantity of vanadium ions in pharmaceutical formulations (PF), dialysate (DS) and parenteral solutions (PS). The CPE of vanadium (V) using 8-hydroxyquinoline (oxine) as complexing reagent and mediated by nonionic surfactant (Triton X-114) was investigated. The parameters that affect the extraction efficiency of CPE, such as pH of sample solution, concentration of oxine and Triton X-114, equilibration temperature and time period for shaking were investigated in detail. The validity of CPE of V was checked by standard addition method in real samples. The extracted surfactant-rich phase was diluted with nitric acid in ethanol, prior to subjecting electrothermal atomic absorption spectrometry. Under these conditions, the preconcentration of 50 mL sample solutions, allowed raising an enrichment factor of 125-fold. The lower limit of detection obtained under the optimal conditions was 42 ng/L. The proposed method has been successfully applied to the determination of trace quantity of V in various pharmaceutical preparations with satisfactory results. The concentration ranges of V in PF, DS and PS samples were found in the range of 10.5-15.2, 0.65-1.32 and 1.76-6.93 microg/L, respectively.

Multi-elements (aluminium, copper, magnesium, manganese, selenium and zinc) determination in serum by dynamic reaction cell-inductively coupled plasma-mass spectrometry

BACKGROUND

Trace element determination in laboratory medicine is widely carried out by atomic absorption or emission spectroscopy. In the last decade, there has been a rapid growth in the use of inductively coupled plasma-mass spectrometry because of its strong detection power, and the possibility of multi-elements analysis in a single run.

METHODS

Having the advantages of smaller sample volume and better detection limit, we developed a method for the simultaneous determinations of six trace elements by using 100 microL serum, and the assay can be accomplished within 3 min.

RESULTS

The method developed gave recovery of the six elements ranging from 97% to 117%. The method covered a wide dynamic range with manganese in the range of nmol/L, while magnesium was in the range of mmol/L. The detection limits were 0.001 mmol/L, 0.05 micromol/L, 2.0 nmol/L, 0.2 micromol/L, 0.05 micromol/L, and 0.01 micromol/L for magnesium, aluminium, manganese, copper, zinc, and selenium, respectively. All the six elements had intra-assay imprecision of less than 5%, and inter-assay imprecision of less than 8%.

CONCLUSIONS

This fast and robust method is suitable for use in the clinical laboratory where short turnaround time is needed for managing patients with trace element deficiency or toxicity.

On-line preconcentration/determination of copper in parenteral solutions using activated carbon by inductively coupled plasma optical emission spectrometry

A method for the on-line preconcentration of copper using a minicolumn packed with activated carbon and its subsequent determination by inductively coupled plasma optical emission spectrometry (ICP-OES) coupled with flow injection (FI) was studied. In order to determinate the copper concentration present in parenteral solutions; it was retained on activated carbon (AC) at pH 9.5. A sensitivity enrichment factor of 30-fold was obtained with respect to the copper determination by ICP-OES without preconcentration. The detection limit for the preconcentration of 25 ml of sample was 0.1 microgl(-1). The precision for the ten replicate determinations at the 2.5 microgl(-1) Cu level was 3.0% relative standard deviation (R.S.D.), calculated with the peak heights. The calibration graph using the preconcentration method for cooper species was linear with a correlation coefficient of 0.9996 at levels near the detection limits up to at least 200 microgl(-1). The method was successfully applied to the determination of copper in parenteral solutions.

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.

Selenium and zinc levels in surgical patients receiving total parenteral nutrition

The zinc and selenium levels of 40 surgical patients were monitored pre- and post-TPN. The initial selenium level was low normal, and the initial zinc level was also low. Both selenium and zinc are potent antioxidants involved in cellular defense against free radicals. Surgical patients are at risk for selenium and zinc deficiencies secondary to both increased needs and losses. TPN blood work protocols should include monitoring of selenium and zinc with supplementation of the nutrient solutions, as required.

Determination of copper levels in serum of healthy subjects by atomic absorption spectrometry

Copper levels in serum samples of 84 healthy subjects living in southeastern Spain were determined using the flame atomic absorption spectrometry technique. Mineralization of samples was carried out with an HNO3/HClO4 (4:1) mixture in a thermostated mineralization block. The accuracy of the method was tested by using a standard reference material. A mean recovery percentage of 104.70% was obtained. The relative standard deviation (R.S.D.) as a measurement of the precision of the method was lower than 5% in the concentration range considered. Mean copper concentrations were 1.092 +/- 0.365 mg/l (with the range 0.304-2.000 mg/l) and 1.113 +/- 0.253 mg/l (corresponding to an interval of 0.648-1.760 mg/l) for women and men, respectively. There are no significant differences between the copper levels in serum according to either sex or geography zone (P > 0.05). For example, there were no differences of copper levels in serum of subjects from coastal and mountainous zones. Estimated daily dietary intakes on copper in women and men were 1.38 and 2.10 mg Cu/day respectively.

Neurologic disorders due to brain manganese deposition in a jaundiced patient receiving long-term parenteral nutrition

BACKGROUND

Neurologic and radiologic disorders have been reported in patients receiving long-term parenteral nutrition (PN). On the basis of elevated serum manganese levels, some of these abnormalities have been attributed to manganese intoxication. Alterations of the basal ganglia signal intensity on T1-weighted magnetic resonance images (MRIs) have been previously reported, but the precise nature of these alterations remains controversial although the deposition of manganese has been suggested in patients with chronic hepatic encephalopathy due to liver failure.

METHODS

We report the case of a patient who was receiving PN and exhibited a chronic cholestasis. Neurologic disorders appeared after several months of PN, when a hypersignal in the basal ganglia and white matter was found on T1-weighted MRIs of the brain in association with elevated serum and manganese levels.

RESULTS

Elevated autopsic concentrations of manganese were found in the radiologic abnormal cerebral areas.

CONCLUSIONS

Our observation is the first demonstration of a relationship between high intracerebral manganese levels, radiologic abnormalities, and neurologic disorders during long-term PN. Moreover, serum manganese levels are not a good indicator of cerebral levels. In fact, in our patient, serum manganese levels returned to normal, whereas those of cerebral manganese remained increased.

Copper, selenium, and zinc status and balances after major trauma

To investigate the trace elements (TE) losses and status after trauma, 11 severely injured patients (Injury Severity Score: 29 +/- 6), admitted to the ICU were studied from the day of injury (D0) until D25. Balance studies were started within 24 hours after injury, until D7. Serum and urine samples were collected from D1 to D7, then on D10, 15, 20, and 25. Intravenous TE supplementation was initiated upon admission. SERUM: Selenium (Se) and zinc (Zn) levels were decreased until D7 and were normal thereafter. LOSSES: TE urinary excretions were higher than reference ranges until D20 in all patients. Fluid losses through drains contained large amounts of TE. BALANCES: Balances were slightly positive for copper (Cu) and Zn, and negative for Se from D5 to D7 despite supplements. Cu status exhibited minor changes compared to those observed with the Zn and Se status: Serum levels were decreased and losses increased. Considering the importance of Se and Zn in free radical scavenging, anabolism, and immunity, current recommendations for TE supplements in severely traumatized patients ought to be revised.

Trace elements in parenteral micronutrition

OBJECTIVE

To update some essential trace metals required in total parenteral nutrition.

CONCLUSION

Essential trace metals, chromium, copper, manganese, molybdenum, selenium, and zinc are added to parenteral fluids to prevent the development of deficiency syndromes. When possible, these metals should be monitored, even in patients on short-term total parenteral nutrition (TPN) to avoid deficiency or toxicity. Many of the nutrients or additives used in parenteral solutions may be contaminated with metals, such as aluminum or chromium. Such trace-metal monitoring becomes more critical in infants, and those on long-term TPN.

[Role of trace elements and vitamins in peri-operative nutrition]

The micronutriment requirements, whether trace elements (inorganic) or vitamins (organic), are tightly linked to the carbohydrate, lipid and protein metabolism, since they are involved in all metabolic pathways as cofactors. The micronutriments also have major immunological, endocrinological and antioxydant functions. Especially in the surgical patient, individual requirements may vary considerably and will be particularly increased in case of prior deficiency, anabolic states, or increased losses (burns, diarrhoea, gastric aspiration, intestinal fistulae, alcoholism, use of renal replacement techniques). In some of these settings, the micronutriment requirements will be independent from the macronutriments: this has been demonstrated for burns and intestinal fistulae. In the case of depletion prior to surgery, an isolated supplementation may be required without starting a proper nutrition. In general, micronutriment supplements will have to be started upon initiation of any artificial nutrition. After elective surgery and in absence of specific losses, the micronutriment requirements will be linked to the metabolic state of the patient and to the energy-protein intakes. This is most striking for the vitamin B group, where the requirements are indicated in mg per 1000 kcal. Vitamins A and E are also at risk in the surgical patient. Recommended micronutriment supplements have been revised in 1994. Some trace element deficiencies (Se, Cr, Mo) can initiate very serious complications and will require special caution in the perioperative period. Other deficiencies (Cu, Zn) result in more slowly evolving clinical pictures, with lesser life-threatening potential, resulting in infections and prolonged wound healing. In such cases, multi-elementary supplements are inadequate, and single element solutions supplements are required. All the micronutriments are characterized by a dose-response curve. The quantity avoiding biochemical dysfunctioning in human pathological situations has not yet been established, and it is unsatisfactory to merely compensate for the losses. This notion of biochemical dysfunctioning phase preceeding the clinical deficiency syndrome is in investigation for many nutriments, especially as the importance of some micronutriments, such as Se and vitamin E, in maintaining antioxidant defences is clearly established. The potential for preventing free radical induced overproduction of cytokines by means of nutritional strategy and enhanced antioxidant defences clearly exists, and is only at an early phase of investigation in patients. The future will be marked by the development of nutritional pharmacology based on pathology-specific micronutriment supplements.

[Unrecognised intake of trace elements in polytraumatized and burnt patients]

Recommended trace element doses during parenteral nutrition have been revised many times and increased, especially in surgical patients. Blood products are known to provide significant amounts of trace elements under certain circumstances. In intensive care patients crystalloids and colloids are also given in large amounts. This study aimed at determining the magnitude of the unrecognized trace element administrations after major burns and/or trauma. Fifteen patients burnt 36 +/- 11% (mean +/- SD) of body surface area, aged 34 +/- 8 years, admitted to the Burns Centre and 11 trauma patients with an Injury Severity Score of 29 +/- 6 points, aged 40 +/- 13 years, admitted to the surgical Intensive Care Unit in a Swiss University Hospital. Prospective study of intakes and urinary excretion from the first post-injury day (D1) to D7. Copper and zinc were analyzed by flame atomic absorption spectrophotometry, and selenium by fluorimetry. The actual trace element administrations were much larger than those prescribed in the 3 groups of patients, and were significantly above the most recent parenteral recommended daily allowance = RDA (2.3 times RDA for copper, 5 times for selenium and zinc in Group 2, which received the largest i.v. supplements). There greatest provision of the 3 elements was by the blood products (packed red cells and frozen plasma) and by the albumin solutions (0.5 mg.L-1 Cu, 90 micrograms.L-1 Se and 2.1 mg.L-1 Zn in the 20% solutions). During the resuscitation phase, crystalloids provided a significant amount of copper (0.14 mg.L-1 NaCl 0.9%, none in dextrose) and zinc (0.3 mg.L-1 of any crystalloid), whereas selenium was not detected.(ABSTRACT TRUNCATED AT 250 WORDS)