toxicology

Methemoglobinemia vs CO Poisoning

Toxicologic Hypoxemia

Methemoglobinemia vs CO Poisoning
Feature	Methemoglobinemia	Carbon Monoxide Poisoning
Mechanism
SpO₂ Reading	Reads ≈85% regardless of MetHb level	Reads falsely NORMAL or high
PaO₂	NORMAL	NORMAL
Specific Antidote	Methylene blue (NOT for G6PD deficiency)	High-flow O₂ (no specific drug)

Comparing: Methemoglobinemia

Reads ≈85% regardless of MetHb level

NORMAL

Methylene blue (NOT for G6PD deficiency)

For healthcare-professional education. Clinical decisions require patient-specific assessment and local protocols.