Severe pulmonary oedema following therapeutic embolization with Onyx for cerebral arteriovenous malformation.

Acute respiratory distress syndrome (ARDS) is characterized by sudden onset of respiratory distress, infiltrates on radiographs consistent with pulmonary oedema, hypoxaemia and increased work in breathing. Infiltrates on radiographs are bilateral, but may be patchy or diffuse and fluffy or dense. It is associated with absence of left heart failure and a PaO2/FiO2 ratio of < or =200. Ethylene vinyl alcohol copolymer dissolved in dimethyl sulfoxide (DMSO), which was approved by the US FDA in July 2005, is used as an embolic agent for cerebral arteriovenous malformation (AVM). It is a biocompatible liquid polymer that precipitates and solidifies on contact with blood, thus forming a soft and spongy embolus. We report a case of ARDS following therapeutic embolization with ethylene vinyl alcohol copolymer for cerebral AVM under general anaesthesia. Experienced perioperative physicians adopted standard anaesthetic technique and monitoring for this procedure. Acute respiratory distress and hypoxaemia developed in the patient following extubation of the trachea. Infiltrates seen on postprocedural chest radiographs were consistent with pulmonary oedema. DMSO, the solvent for the ethylene vinyl alcohol copolymer, is excreted via the lungs after administration and we postulate that DMSO was the possible cause of ARDS in this patient. Monitoring of haemodynamic parameters (invasive blood pressure, electrocardiography) and ventilatory parameters (ETCO2, SpO2, airway pressure monitoring) are important in the recognition of this possible event. One should be vigilant and anticipate this complication following therapeutic embolization with ethylene vinyl alcohol polymer for the treatment of cerebral AVM.