## **Core Concept**
Parenteral nutrition refers to intravenous feeding provided to patients who cannot receive nutrition through the gastrointestinal route. During the initial phase of parenteral nutrition, several metabolic and physiological changes occur.

## **Why the Correct Answer is Right**
In the first week of parenteral nutrition, especially if it's initiated properly, patients often experience a positive nitrogen balance. This is because parenteral nutrition provides essential amino acids, which are crucial for protein synthesis. A positive nitrogen balance indicates that the patient is in an anabolic state, where the rate of protein synthesis exceeds the rate of protein breakdown. This state supports healing, reduces muscle wasting, and improves overall nutritional status.

## **Why Each Wrong Option is Incorrect**
- **Option A:** Hypokalemic - While it's possible for patients to have electrolyte imbalances during parenteral nutrition, the initiation of parenteral nutrition often includes careful monitoring and adjustment of electrolytes, including potassium. However, becoming hypokalemic is not a direct consequence of starting parenteral nutrition in the first week.
- **Option B:** Hyperglycemic - Although hyperglycemia can be a complication of parenteral nutrition due to the glucose load, proper management involves monitoring blood glucose levels and adjusting the glucose content of the parenteral nutrition solution accordingly. This option does not universally apply as a typical outcome in the first week.
- **Option C:** Acidotic - Metabolic acidosis can occur but is not the most direct or common outcome specifically attributed to the initiation of parenteral nutrition in the first week. The acid-base status is closely monitored, and adjustments are made as necessary.

## **Clinical Pearl / High-Yield Fact**
A key point to remember is that during the initiation of parenteral nutrition, patients are at risk for refeeding syndrome, a potentially fatal condition that can occur in severely malnourished patients. This syndrome involves severe shifts in fluids and electrolytes (particularly phosphate, magnesium, and potassium) and can lead to serious complications. Close monitoring and careful adjustment of electrolytes and nutrients are crucial.

## **Correct Answer:** D. Positive nitrogen balance.