Which of the following is an indication for the use of parenteral nutrition (PN)?

• A. High output fistula
• B. Crohn's disease
• C. Pancreatitis
• D. Hyperemesis gravidarum

Answer: (A)

The main concept tested is that parenteral nutrition is used when the gut cannot provide adequate nutrition or cannot be used safely. A high‑output fistula causes continuous, substantial losses of fluids, electrolytes, and nutrients through the fistula, making enteral feeding unreliable and often insufficient to meet metabolic needs. In this situation, bypassing the gastrointestinal tract with parenteral nutrition delivers calories and protein directly into the bloodstream, supporting nitrogen balance and healing while the fistula is treated.

Other conditions sometimes bring consideration for parenteral nutrition, but they are not the classic, definitive indications. For example, Crohn’s disease and pancreatitis may require PN if the patient is severely malnourished or cannot tolerate enteral feeding, but early and adequate enteral nutrition is usually preferred when feasible. Hyperemesis gravidarum is typically managed with fluids, electrolytes, and antiemetics, with PN reserved for rare cases where oral/enteral intake cannot be maintained.