<unk> moglobin refers to ferric form of hemoglobin (Fe3+) that is unable to bind O2
Suspect in any patient with cyanosis not responsive to supplemental O2
Consider in pediatric patient (<6 months) with diarrhe and low oxygen saturation
Consider in pediatric patient (<6 months) with diarrhe and low oxygen saturation
Rarely congenital, NADH reductase deficiency - unable to reduce ferric to ferrous iron (Fe3+ → Fe2+)
Exposure to oxidizing agent
Benzocaine and other local anesthetics
Cyanokit, nitrites, nitrates, well water (nitrates)
Antimalarials
Quinolones
Dapsone (used to treat leprosy, PCP pneumonia, toxoplasmosis, dermatitis herpetiformis, brown recluse bite)
Aniline dyes
Phenazopyridine
Benzocaine and other local anesthetics
Cyanokit, nitrites, nitrates, well water (nitrates)
Antimalarials
Quinolones
Dapsone (used to treat leprosy, PCP pneumonia, toxoplasmosis, dermatitis herpetiformis, brown recluse bite)
Aniline dyes
Phenazopyridine
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