
Summary: We present the case of a woman who developed a cyanotic appearance after methylene blue (MB) administration during elective laparoscopic hysterectomy, triggering concern for acute methemoglobinemia.
Background: Properties of methylene blue are reviewed, particularly its role as a treatment for acquired methemoglobinemia, but also itspotential to paradoxically cause this condition, particularly in patients with G6PD deficiency.
Conclusion: This patient's bluish appearance was asymptomatic and associated with normal methemoglobin (MetHb) levels, resolving spontaneously within a few hours. Previous reports in the literature describe a similar blue skin discoloration without evidence of true cyanosis after large doses of MB, but we are the first to report this phenomenon with administration in a small quantity as an intraoperative indicator dye.
Keywords: Methylene blue, methemoglobinemia, cyanosis, glucosephosphate dehydrogenase deficiency