Anaesthesia for a patient with congenital methaemoglobinaemia and temporomandibular joint ankylosis

We report a 10-year-old child with congenital methaemoglobinaemia and temporomandibular joint ankylosis who presented for ophthalmic surgery. He had had two previous anaesthetics in another institution. The first was short and uneventful, and no abnormality was noted. During the second anaesthetic, low haemoglobin oxygen saturation on pulse oximetry was noted after an inhalational induction. The diagnosis was not apparent and the management of the apparent hypoxaemia markedly complicated the clinical course. The patient required prolonged intensive care and tracheostomy. The tracheostomy was ultimately decannulated. Before his third anaesthetic (after referral to the authors' institution) preoperative investigation revealed that the patient, his father and brother all had methaemoglobinaemia.