Anaesthetic management of Osler-Weber-Rendu syndrome with coexisting congenital methaemoglobinaemia.

A 9-year-old cyanosed child suffering from Osler-Weber-Rendu syndrome with bilateral pulmonary arteriovenous malformations (PAVMs) was posted for cerebral angiography under general anaesthesia. Careful preanaesthetic evaluation led to the diagnosis of coexisting congenital methaemoglobinaemia. There is no previous report of Osler-Weber-Rendu syndrome coexisting with congenital methaemoglobinaemia. This report emphasizes that a second contributory cause of cyanosis must be suspected and meticulously looked for if the symptomatology in a patient cannot be explained by a single established diagnosis. Positive-pressure ventilation was associated with reduction in arterial oxygenation despite an increasing inspired oxygen concentration, which returned to preanaesthetic levels only after extubation and resumption of spontaneous respiration.