In this case presentation the patient was admitted to ICU for haemodiafiltration to control her potassium. Despite initial fluid removal of 100ml/hr her oxygenation deteriorated and repeat chest X-ray showed diffuse alveolar infiltrates. The nurses noted small volume haemoptysis overnight. 24 hours after admission to the intensive care, the immunology lab contacted the intensive care unit to inform them that the patient was found to have a positive ANCA with antibodies directed to PR3.