Severe methaemoglobinaemia after flexible fibreoptic bronchoscopy.

A patient with the acquired immunodeficiency syndrome (AIDS) developed severe cyanosis after bronchoscopy (oxygen saturation 34%) from methaemoglobinaemia. This was thought to be due to enhanced absorption of local anaesthetic from the nasopharynx or trachea as a result of candidiasis. The patient responded dramatically to intravenous methylene blue.