Correct Answer to Question#05

Question#05

You diagnose necrotizing enterocolitis in a preterm neonate who has abdominal distention and blood in the stool. You decide that this infant should be placed on a 14-day regimen of parenteral nutrition.

Of the following, the micronutrient for which weekly monitoring is MOST recommended during this infant’s parenteral nutrition therapy is

A. copper

B. iron

C. phosphorus

D. selenium

E. zinc

Correct Option to this  Question is 'C'

Explanation:

Parenteral nutrition (PN), the intravenous administration of carbohydrates, lipids, amino acids, and micronutrients, is an important component in the management of a variety of chronic disorders, including surgical conditions (eg,

omphalocele, gastroschisis, diaphragmatic hernia, short bowel syndrome), inflammatory conditions (eg, Crohn disease, ulcerative colitis, pseudomembranous colitis, pancreatitis, graft versus host disease), hypermetabolic states (eg, burns, trauma), and intestinal motility disorders (eg, pseudo-obstruction). PN is especially important in the support of very low-birthweight infants, who frequently have increased caloric requirements, decreased oral intake, and immature intestinal motility.

In addition to glucose, amino acids, sodium, potassium,

and chloride, PN provides additional mineral supplements, including calcium, phosphorus, magnesium, zinc, copper, selenium, chromium, manganese, molybdenum, and iodide. In preterm infants, the administration of both calcium and phosphorus is important to prevent metabolic bone disease.

However, the amount of calcium and phosphorus that can be administered in PN must be limited because of the risk of precipitation in the PN and formation of calcium-phosphorus complexes that could embolize. It generally is thought that

the chance of precipitation is high if the product of the concentrations (in mmol/L) of the calcium and phosphorus in PN is greater than 40. Because hypophosphatemia can have significant consequences (including impaired cardiac function, muscle weakness, and hemolysis), it is recommended that serum phosphorus concentrations be assessed at least once weekly for patients receiving PN. The serum concentrations of copper, iron, selenium, and zinc, which are trace elements, require only periodic assessment (eg, once a month or less).