Fluids, Electrolytes, Acid-Base Disorders, and Nutrition Support

Zinc 3 mg/day normal requirements; 5 mg/day during critical illness; increased requirements

for patients with diarrhea, intestinal fistulae. An additional 10 mg/day for a total of 13 mg/

day is usually sufficient to meet increased intestinal losses (Gastroenterology 1979;76:458-67).

Deficiency is characterized by loss of hair; erythematous rash, especially in periorbital regions

of face; poor wound healing. Classic zinc deficiency is termed acrodermatitis enteropathica.

ii.

Copper 0.3–0.5 mg/day is usually sufficient (Gastroenterology 1981;81:290-7). Historically,

copper deficiency was considered to be a rare condition, but incidence of deficiency has become

more common, particularly in patients who have undergone bariatric surgeries for weight loss

and patients in the ICU who have received greater than 7–10 days of CRRT (Curr Opin Crit

Care 2021;27:367-77; Nutr Clin Pract 2018;33:439-46). Classic presentation of copper deficiency

includes a microcytic anemia unresponsive to iron therapy, pancytopenia, neuropathies and

myelopathies presenting as numbness, tingling, pain, weakness, loss of coordination, falls,

vision changes, and dysphagia. Clinical signs may mimic myelodysplastic syndromes and

may be masked by findings that are common among critically ill patients (Practical Gastro

2020;44:24-32). Rather than omitting copper from PN in patients with hyperbilirubinemia

(a common practice historically because of concern for accumulation), this author suggests

checking a serum copper level along with a c-reactive protein level with empiric provision

of copper 0.3 mg daily in PN until copper level returns (typically a send-out test). Because

copper levels increase in the setting of inflammation, one can be confident that a serum copper

level below the normal range in the presence of an elevated C-reactive protein concentration

is indicative of deficiency (Clin Nutr 2022;41:1357-424). Close monitoring of levels should

continue in this case while short courses of repletion doses are provided, especially if clearance

of copper is impaired (e.g. with severe hyperbilirubinemia).

iii.

Chromium 10–12 mcg/day normal requirements, up to 20 mcg/day for diarrhea. Commercially

available PN components have significant levels of chromium contamination. One study found

that chromium was present in 65.6% of all PN components (JPEN J Parenter Enteral Nutr

2019;43:970-76). Therefore, supplementation with additional chromium in the PN formula is

usually unnecessary. Deficiency is rare. Classic presentation of deficiency is hyperglycemia.

iv.

Manganese 150–300 mcg/day is likely sufficient. Some studies state that the amount of

manganese contamination in the compounding of PN may be adequate as opposed to

supplementation. Other literature supports a dose of 55 mcg/day in PN formula to maintain

Deficiency has been reported to present as a “diaper rash.” Several case reports of manganese

toxicity associated with liver disease and high manganese intake (800 mcg – 1 mg/day)

Selenium 60 mcg/day up to 120 mcg/day for patients with diarrhea or short bowel syndrome.

Deficiency results in extreme muscle weakness and congestive cardiomyopathy. Classic

presentation with cardiomyopathy has been termed Keshan disease (named after a province

in China where the first cases of selenium deficiency with cardiomyopathy were discovered).

vi.

Typical trace elements requirements can be provided with 1 mL per day of trace elements

injection 4 (dose per 1 mL: zinc 3 mg, copper 0.3 mg, manganese 55 mcg, selenium 60 mcg).

This is the first FDA-approved multi-trace product, and it replaced MTE-5, which was phased

out of production in 2020. It is important to note that this four ingredient product is not

equivalent to the previously available multi-trace 4 (MTE-4) product as it contains different

doses of trace elements and does not contain chromium. Its formulation is more consistent

with current recommendations for parenteral trace elements requirements than previous multi-

trace elements products.