Pseudomethemoglobinemia: a case report and review of sulfhemoglobinemia.

OBJECTIVES To see if methemoglobin could potentially be misdiagnosed and the limitation of present cooximeters. PATIENT A 17-year-old girl who overingested a combination of cimetidine, acetaminophen, ibuprofen, and naproxen in a suicide attempt. METHOD Use of pulse co-oximeters to aid in the diagnosis of suspected sulfhemoglobinemia. RESULTS Diagnosis of sulfhemoglobinemia achieved with final confirmation made with gas chromatography. Patient steadily improved with supportive care. CONCLUSIONS There is a potential for the diagnosis of methemoglobin with some of the limitations of present co-oximeters. The laboratory diagnosis of sulfhemoglobinemia can be difficult to make.