A 7-year-old boy is going to undergo orthopedic surgery for right total hip replacement; he has been diagnosed with Addison disease 2 years ago and he is on replacement therapy by hydrocortisone since that time. Of the following, the MOST important step in the management of this boy is

Correct Answer: D

Rationale: In Addison disease, surgery is a stress requiring increased hydrocortisone (stress dosing) to prevent adrenal crisis, making it the most important step. Monitoring (A), fludrocortisone (B), and fluids (E) are supportive, and surgery (C) proceeds after stabilization.

Correct Answer: D

Rationale: Type V (McArdle) has a good prognosis as it primarily causes exercise intolerance without systemic failure. Type 1a (A) and 1b (B) require careful management, type II (C) is fatal without treatment, and type IV (D) progresses to liver failure.

Correct Answer: A

Rationale: Transient tyrosinemia of the newborn, due to immature liver enzymes, resolves with ascorbic acid (vitamin C), which enhances tyrosine metabolism, unlike other vitamins or formulas.

Correct Answer: A

Rationale: Isovaleric acidemia produces a distinctive 'sweaty feet' odor from isovaleryl-CoA accumulation, unlike other listed disorders.

Correct Answer: D

Rationale: Galactosylceramide lipidosis (Krabbe) causes optic atrophy due to white matter degeneration, unlike other listed lipidoses where it’s less prominent.