A 59-year-old man receiving high-dose nitroprusside for hypertensive emergency (BP 210/120 mmHg, HR 102, RR 18, SpO2 98% on room air) becomes progressively confused over 6 hours. Laboratory studies reveal severe lactic acidosis (pH 7.21, lactate 8.2 mmol/L) despite adequate oxygenation and normal renal function. He denies chest pain and has no focal neurologic deficits. Which of the following best explains this complication?
- A)Generation of cyanide with inhibition of cytochrome oxidaseGABARITO
- B)Accumulation of NAPQI
- C)Inhibition of aldehyde dehydrogenase
- D)Acetylcholinesterase inhibition
- E)Direct oxidation of hemoglobin iron to Fe3+ only
Explicação
Nitroprusside metabolism can release cyanide, especially with prolonged high dose infusion. Cyanide inhibits mitochondrial cytochrome oxidase, blocking oxidative phosphorylation and causing lactic acidosis. Ver explicação completa e trilha adaptativa →