Toxicology USMLE Step 1 Practice Question
A 3-month-old infant presents to the emergency department with cyanosis following infiltration of lidocaine during a minor surgical procedure. Vital signs show HR 155 bpm, RR 38, BP 70/45, SpO2 78% on room air. Arterial blood gas reveals normal PaO2 of 95 mmHg and pH 7.32. Methemoglobin level is elevated at 8%. The infant has no respiratory distress or wheezing. Which of the following treatments is most appropriate?
Answer choices
- AMethylene blueCorrect answer
- BPralidoxime
- CFomepizole
- DHyperbaric oxygen
- EPhysostigmine
- FNitroprusside
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