Manganese toxicity and parenteral nutrition

Liver disease secondary to intestinal failure

IFALD is a common and potentially life-threatening condition for patients with SBS requiring long-term PN. There exists the potential for decreasing its incidence by optimizing the composition and the rate of infusion of parenteral solutions, by advocating a multidisciplinary approach, and by early referral for intestinal-liver transplantation to ensure long-term survival of patients with SBS.

Complications of parenteral nutrition

Parenteral nutrition plays a vital role for patients with intestinal failure and those who are unable to maintain oral or enteral nutrition alone. Parenteral nutrition has been shown to improve clinical outcome in patients with malnutrition and intestinal tract dysfunction. The use of parenteral nutrition is not without risk of serious complications. Parenteral nutrition complications can be divided into mechanical related to vascular access, septic, and metabolic. This article provides a review on the short- and long-term complications of parenteral nutrition and their management.

Intestinal replacement therapy: timing and indications for referral of patients to an intestinal rehabilitation and transplant program

Current treatment options for patients suffering from intestinal insufficiency include all forms of intestinal replacement therapy (IRT). Parenteral nutrition has achieved extended success for the majority of patients requiring interval treatment, however, complications leading to failure of this treatment increases with the duration of therapy. There is currently no consensus as to the appropriate timing for transplantation of the intestine or the timing of referral for evaluation at a center experienced with this therapy. Certain patient characteristics warrant evaluation. Those patients with no jejunoileum who have guaranteed lifelong parenteral dependence, both adult and pediatric, should be immediately referred to a transplant center due to the high likelihood of the development of liver disease. Patients with metastatic infectious complications from catheter sepsis, patients with cholestasis seen intermittently with sepsis episodes, patients who are not successfully weaning and who demonstrate progressive thrombocytopenia, and patients with motility disorder experiencing deterioration should also warrant early referral to an intestinal rehabilitation and transplant program. The objective of evaluation is to maximize the opportunities for rehabilitation while not missing the critical window of opportunity for successful transplantation when needed. We favor an aggressive directed approach to rehabilitation, coupled with psychological preparation for both transplantations and other options. Early referral requires trust between the patient, referring physician, and the transplant team to assure that a rush to judgment will not lead to a premature transplant. The current wait list mortality is high, mandating early referral and listing with an approach aimed at maximizing both the success of gastrointestinal support, as well as of transplantation when necessary.

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.

Complications of long-term home total parenteral nutrition: their identification, prevention and treatment

The purpose of this review is to describe the most common complications of home total parenteral nutrition, their identification, treatment and prevention. Data sources were manuscripts and abstracts published in the English literature since 1968. Studies were selected for summarization in this review on the basis of clinical relevance to the practicing clinician. Home total parenteral nutrition is a relatively safe, life-saving method for nutrient delivery in patients with compromised gastrointestinal function. However, numerous complications, with associated morbidity and mortality, involving the delivery system and the gastrointestinal, renal, and skeletal systems may develop. Catheter-related complications are often preventable and treatable when they occur, although renal and bone abnormalities have elusive etiologies.

Hypermanganesemia in long-term intravenous nutrition and chronic liver disease

BACKGROUND

Hypermanganesemia and cholestatic liver disease are both recognized complications of long-term IV nutrition. Manganese is primarily excreted in bile, and recent studies have indicated that manganese toxicity may play a role in the pathogenesis of IV nutrition-associated cholestasis.

METHODS

Whole blood and plasma manganese concentrations were measured in patients receiving long-term home IV nutrition (HIN, n = 30). Whole blood manganese concentrations also were measured in patients with chronic liver disease (CLD, n = 10) and control subjects (n = 10).

RESULTS

Whole blood manganese concentrations of all CLD patients were within the reference interval (73 to 210 nmol/L) and were not different from those of the control group (151 +/- 44 nmol/L, CLD vs 155 +/- 35 nmol/L, control; not significant), despite the presence of cholestasis. In contrast, whole blood manganese concentration was increased (>210 nmol/L) in 26 patients, and plasma manganese concentration increased (>23 nmol/L) in 23 of the patients receiving HIN. None of the patients exhibited neurologic signs of manganese toxicity. There was no correlation between whole blood manganese concentrations and markers of cholestasis, IV manganese intake, or duration of HIN. However, plasma manganese concentration correlated both with average weekly IV manganese intake (r = .44, p = .02) and with gamma-glutamyl transferase (r = .43, p = .02) and alkaline phosphatase activities (r = .55, p = .003).

CONCLUSIONS

Cholestatic liver disease does not appear to contribute to increased whole blood manganese concentrations in patients not receiving HIN. Plasma manganese concentrations in patients receiving HIN reflect recent manganese exposure and impaired excretion where cholestasis is present. The lack of relationship between plasma and whole blood manganese concentrations suggests that factors other than manganese intake and excretion affect intracellular concentrations.

Manganese deposition in the brain following parenteral manganese administration in association with radical operation for esophageal cancer: report of a case

We report herein the case of a patient in whom manganese (Mn) deposition in the basal ganglia was detected by magnetic resonance imaging (MRI) subsequent to thoracic esophagectomy, performed following perioperative parenteral nutrition. A multi-trace-element supplement solution which included 20 micromol of Mn per day had been parenterally administered for 7 days preoperatively and 21 days postoperatively. The serum level of total bilirubin reached a maximum value of 5.1 mg/dl postoperatively. The T1-weighted MRI on the 32nd postoperative day demonstrated bilateral and symmetrical hyperintense lesions in the globus pallidus and the whole-blood Mn level on the 34th postoperative day was 4.9 microg/l, the normal range being 0.8-2.5 microg/l. This hyperintensity on T1-weighted MRI was gradually improved following normalization of the blood Mn level. This case report serves to demonstrate that even short-term perioperative parenteral nutrition may result in Mn deposition in the brain following radical surgery for esophageal cancer, especially in patients with hyperbilirubinemia.

New approaches to understanding the etiology and treatment of total parenteral nutrition-associated cholestasis

Total parenteral nutrition-associated cholestasis (TPN-AC) may be a fatal disease. The only known effective treatment is to discontinue TPN and institute full enteral feedings. However, this is not possible for many patients with severe gastrointestinal failure. Current research supports two theories regarding the etiology of TPN-AC. One proposes that the enteral fast disrupts the enterohepatic circulation. Cholestasis, in this hypothesis, results from a combination of altered gut hormone production and endotoxins produced by bacterial translocation. The second theory implicates the direct toxicity of TPN solution. Amino acid solutions and plant sterols in intralipid have generated much interest. Ursodeoxycholic acid and S-adenosyl-L-methionine are promising treatments for TPN-AC. They have been proven to be effective in animals and adult liver diseases. Cholecystokinin also has been investigated as a possible prophylactic agent. However, results from these experiments do not conclusively show a beneficial effect.

Manganese deficiency and toxicity: are high or low dietary amounts of manganese cause for concern?

Manganese is an essential trace element that is required for the activity of several enzymes. Manganese is also quite toxic when ingested in large amounts, such as the inhalation of Mn-laden dust by miners. This review examines Mn intake by way of the food supply and poses the question: Is there reason to be concerned with Mn toxicity or deficiency in free-living populations in North America? Although much remains to be learned of the functions of Mn, at present there are only a few vaguely described cases of Mn deficiency in the medical literature. Given the heterogeneity of the North American food supply, it is difficult to see the possibility of more than greatly isolated and unique instances of Mn deficiency. However, low Mn-dependent superoxide dismutase activity may be associated with cancer susceptibility, and deserves further study. There may be reasons, however, to be concerned about Mn toxicity under some very specialized conditions. Increasing numbers of young people are adopting a vegetarian lifestyle which may greatly increase Mn intake. Iron deficiency may increase Mn absorption and further increase the body-burden of Mn, especially in vegetarians. Mn is eliminated primarily through the bile, and hepatic dysfunction could depress Mn excretion and further contribute to the body burden. Would such a combination of events predispose substantial numbers of people to chronic Mn toxicity? At present, there is no definite proof of this occurring, but given the state of knowledge at the present time, more studies with longer time-frames and more sensitive methods of analysis are needed.