Elevated Whole-Blood Manganese Levels in Adult Patients Prescribed "Manganese-Free" Home Parenteral Nutrition

A scoping review of parenteral requirements (macronutrients, fluid, electrolytes and micronutrients) in adults with chronic intestinal failure receiving home parenteral nutrition

INTRODUCTION

Home parenteral nutrition (HPN) prescriptions should be individualised in adults with chronic intestinal failure (IF). The aims of the review were to explore HPN requirements and available guidelines and to determine whether adults (≥ 18 years) receive recommended parenteral nutrient doses.

METHODS

Online databases searches identified empirical evidence (excluding case-reports), reviews and guidelines (Published 2006-2024 in English language). Additional reference lists were hand-searched. Older studies, cited in national guidelines were highlighted to map evidence source. Two reviewers screened 1660 articles independently, with 98 full articles assessed and 78 articles included (of which 35 were clinical studies). Citation tracking identified 12 older studies.

RESULTS

A lack of evidence was found assessing parenteral macronutrient (amounts and ratios to meet energy needs), fluid and electrolyte requirements. For micronutrients, 20 case series reported serum levels as biomarkers of adequacy (36 individual micronutrient levels reported). Studies reported levels below (27 out of 33) and above (24 out of 26) reference ranges for single micronutrients, with associated factors explored in 11 studies. Guidelines stated recommended parenteral dosages. Twenty-four studies reported variable proportions of participants receiving HPN dosages outside of guideline recommendations. When associated factors were assessed, two studies showed nutrient variation with type of HPN administered (multichamber or individually compounded bags). Five studies considered pathophysiological IF classification, with patients with short bowel more likely to require individualised HPN and more fluid and sodium.

CONCLUSIONS

This review highlights substantial evidence gaps in our understanding of the parenteral nutritional requirements of adult receiving HPN. The conclusions drawn were limited by temporal bias, small samples sizes, and poor reporting of confounders and dose. Optimal HPN nutrient dose still need to be determined to aid clinical decision-making and further research should explore characteristics influencing HPN prescribing to refine dosing recommendations.

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.

Sodium P-aminosalicylic Acid Attenuates Manganese-Induced Neuroinflammation in BV2 Microglia by Modulating NF-κB Pathway

Exposure to high levels of manganese (Mn) leads to brain Mn accumulation, and a disease referred to as manganism. Activation of microglia plays an important role in Mn-induced neuroinflammation. Sodium p-aminosalicylic acid (PAS-Na) is a non-steroidal anti-inflammatory drug that inhibits Mn-induced neuroinflammation. The aim of the current study was to explore the role of NF-κB in the protective mechanism of PAS-Na on Mn-induced neuroinflammation in BV2 microglial experimental model. We treated BV2 microglia with 200 μM Mn for 24 h followed by 48 h treatment with graded concentrations of PAS-Na, using an NF-kB inhibitor, JSH-23, as a positive control. MTT results established that 200 and 400 μM PAS-Na treatment increased the Mn-induced cell viability reduction. NF-κB (P65) mRNA expression and the phosphorylation of p65 were increased in Mn-treated BV2 cell, and suppressed by PAS-Na, analogous to the effect of JSH-23 pretreatment. Furthermore, PAS-Na significantly reduced the contents of the inflammatory cytokine TNF-α and IL-1β, both of which were increased by Mn treatment. The current results show that PAS-Na attenuated Mn-induced inflammation by abrogating the activation of the NF-κB signaling pathways and reduced the release of pro-inflammatory cytokines.

The effects of different parenteral nutrition lipid formulations on clinical and laboratory endpoints in patients receiving home parenteral nutrition: A systematic review

BACKGROUND

Home parenteral nutrition (HPN) is a life-sustaining therapy for individuals with intestinal failure in a community setting. It refers to the intravenous infusion of macronutrients, micronutrients, fluids and electrolytes. Routinely used HPN solutions contain different quantities of these components. Consequently, each HPN solution may have different impacts on metabolism, inflammation and oxidative stress. Long-term use of HPN can lead to a number of adverse health outcomes including the development of metabolic bone disease, intestinal failure associated liver disease and poor quality of life but whether, and how, the composition of HPN solutions contributes to these health sequelae is poorly understood. The aim of this study is to systematically review and evaluate the evidence for the differential effects of HPN solutions and to understand what features are associated with differences in clinical endpoints.

METHODS

A systematic literature search was conducted between September and December 2020, and updated in July 2021 using the MEDLINE (Ovid), EMBASE, Scopus, and Web of Science databases. Studies were selected according to the following criteria (a) adult participants (>18 years old) dependent on HPN; (b) randomised controlled trials, prospective cohort and cross-sectional study designs; (c) primary research comparing two or more HPN solutions and (d) published in English language. Data were extracted and study quality assessed using Cochrane Collaboration's tools: Risk of Bias for Randomised Controlled Trials (RCTs); Risk of Bias in Non-Randomised Studies of Interventions; and the Newcastle Ottawa Scale for cross-sectional studies.

RESULTS

Of the 5148 articles identified, seven RCTs, two prospective cohort and one cross-sectional study were included with a total of 295 participants. Studies varied in terms of duration (one to 60 months) and sample size (n = 5 to 88). Ten studies compared lipid emulsions (LE) and one study also compared LE with lipid-free HPN. No studies were found that compared the amino acid, vitamin, trace element or electrolyte components of HPN. In general, LE were well tolerated with no significant adverse effects. LE containing olive +/or fish oil were associated with a lower ω-6:ω-3 fatty acid ratio, positive reductions in markers of liver function, and changes in blood and cell fatty acid profiles.

CONCLUSIONS

Despite the increasing use of HPN, there is surprisingly little evidence available to guide the provision of macro and micronutrients in the adult population requiring this therapy. Although LE containing olive +/or fish oil show promise with regards to liver function and blood and cell fatty acid profiles, further studies are needed before drawing definitive conclusions on the clinical value of these emulsions. It is likely that one type of HPN solution alone cannot be uniformly applied to patient care, and each patient should be assessed on an individual basis.

Manganese concentration in patients with encephalopathy following ephedrone use: a narrative review and analysis of case reports

BACKGROUND

Numerous case reports describe manganese encephalopathy in patients using ephedrone (methcathinone). The aim of this narrative review of case reports was to relate manganese ion concentrations in peripheral blood to the reported neurological deficits.

METHODS

International databases, including Thomson (Web of Knowledge), PubMed/Medline, Science Direct, Scopus and Google Scholar were searched for literature items published between 2007 and 2020, in which the authors measured the manganese concentration in patients taking ephedrone.

RESULTS

We identified 39 patients in two case series comprising of twenty-three and twelve patients, respectively, and four case reports meeting inclusion criteria. The study showed that 93% of them had elevated blood manganese concentration in relation to the accepted norm (>219 nmol/L), and the median was 364 nmol/L. The median duration of ephedrone use in individual groups of patients was approximately 48 months, and it did not show a relationship with the manganese concentration in the blood. A greater percentage of the people with manganese concentration higher than 250 nmol/L exhibited more severe gait, speech and handwriting disorders. The median duration of ephedrone withdrawal was a month in the group of people with the highest level of manganese ions (>500 nmol/L).

CONCLUSION

Manganese concentrations did not vary with the duration of ephedrone use.

Evaluating the risk of manganese-induced neurotoxicity of parenteral nutrition: review of the current literature

INTRODUCTION

Several diseases and clinical conditions can affect enteral nutrition and adequate gastrointestinal uptake. In this respect, parenteral nutrition (PN) is necessary for the provision of deficient trace elements. However, some essential elements, such as manganese (Mn) may be toxic to children and adults when parenterally administered in excess, leading to toxic, especially neurotoxic effects.

AREAS COVERED

Here, we briefly provide an overview on Mn, addressing its sources of exposure, the role of Mn in the etiology of neurodegenerative diseases, and focusing on potential mechanisms associated with Mn-induced neurotoxicity. In addition, we discuss the potential consequences of overexposure to Mn inherent to PN.

EXPERT OPINION

In this critical review, we suggest that additional research is required to safely set Mn levels in PN, and that eliminating Mn as an additive should be considered by physicians and nutritionists on a case by case basis in the meantime to avoid the greater risk of neurotoxicity by its presence. There is a need to better define clinical biomarkers for Mn toxicity by PN, as well as identify new effective agents to treat Mn-neurotoxicity. Moreover, we highlight the importance of the development of new guidelines and practice safeguards to protect patients from excessive Mn exposure and neurotoxicity upon PN administration.

British Intestinal Failure Alliance (BIFA) guidance - haematological and biochemical monitoring of adult patients receiving home parenteral nutrition

Home parenteral nutrition (HPN) is necessary for patients with prolonged intestinal failure which can be secondary to a variety of pathophysiological mechanisms or surgical resection. HPN is needed to supply micronutrients, macronutrients and water to reduce morbidity and mortality and to maximise the patient's quality of life. HPN requires close monitoring by a dedicated multidisciplinary team and is vital to minimise complications; both catheter related and metabolic. A regular comprehensive review is required including history, examination including anthropometry and blood testing. The focus of this review is on the monitoring of haematological and biochemical parameters. There is a paucity of evidence-based literature on the biochemical monitoring of HPN and existing guidance is sourced mostly on expert opinion and lower grade studies. Sources offering guidance on the frequency of biochemical monitoring for the stable adult HPN patient are the British Association for Parenteral and Enteral Nutrition, the European Society for Parenteral and Enteral Nutrition, the National Institute for Health and Care Excellence and the Australasian Society of Parenteral and Enteral Nutrition (AuSPEN). The aim of this work is to review and collate this existing guidance into one clear and concise review. It is recommended that biochemical parameters are checked at baseline, thereafter more frequently if concerns arise and less frequently when the patient's condition is stable, as assessed by the multidisciplinary team with expertise in HPN.