Hidden hypoxaemia: Dapsone-induced methaemoglobinaemia in complex airway surgery

This case report details the perioperative management of a patient with epidermolysis bullosa who developed acquired methaemoglobinaemia from dapsone therapy before a tracheal dilatation. Challenges included unreliable pulse oximetry and balancing methaemoglobinaemia resolution with urgent airway needs. Management entailed reducing the dapsone dose, instituting regular doses of ascorbic acid, administering oxygen and giving a blood transfusion, while postponing surgery for 2 weeks. Contribution: The report highlights the need for individualised perioperative care, considering methaemoglobinaemia severity, anaemia, and surgical urgency, together with multidisciplinary collaboration for safe outcomes in complex cases.