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?
- A)Methylene blueGABARITO
- B)Pralidoxime
- C)Fomepizole
- D)Hyperbaric oxygen
- E)Physostigmine
Explicação
Methemoglobinemia occurs when hemoglobin iron is oxidized to the ferric state, impairing oxygen delivery. It can be caused by oxidant drugs such as benzocaine, dapsone, and nitrates. Methylene blue reduces Fe3+ back to Fe2+ via NADPH-dependent pathways. Ver explicação completa e trilha adaptativa →