^Patients with anemia or preexisting cardiopulmonary disease will show symptoms sooner
Ask about family or personal history of G6PD deficiency as<unk> lene blue contraindicated
Methemoglobinemia
Consider rare entity of sulfhemoglobinemia
Sulfhemoglobinemia
Sulfonamides, sulfasalazine, phenazopyridine
Dyshemoglobinemia
Occupational exposure
Hypoxemia
Conventional co-oximerty misidentifies sulfhemoglobin as methemoglobin so diagnosis is suspected when patient does not respond to methylene blue