Sulfhemoglobinemia
Background
- Occurs when a sulfer atom binds to porphyrin ring of hemoglobin, resulting in permanent oxidation of iron to the ferric state, incapable of oxygen transport
- Most often associated with phenazopyridine, dapsone, metaclopramide, sumatriptan
- Also associated with industrial chemicals, including trinitrotoluene, hydroxyl amine sulfate, dimethyl sulfoxide, hydrogen sulfide
Clinical Features
- Similar to that of methemoglobinemia
- Cyanosis, anxiety, headache, weakness, lightheadedness, tachycardia, MI, AMS, seizure
Differential Diagnosis
Evaluation
- Standard pulse ox tends to report falsely low value
- ABG, Co-oximetry
- Dark greenish-black blood
Management
- Supportive care
- Severe toxicity may require exchange transfusion or PRBC transfusion
- Methylene blue does not reduce sulfhemoglobin levels
Disposition
See Also
External Links
References
- Tintinalli's Emergency Medicine 7th Edition, pg 1329-30