RT Journal Article SR Electronic T1 Pop goes the O2: a case of popper-induced methaemoglobinamia JF BMJ Case Reports FD BMJ Publishing Group Ltd SP bcr2012007176 DO 10.1136/bcr-2012-007176 VO 2012 A1 Aileen McCabe A1 Brendan McCann A1 Paul Kelly YR 2012 UL http://casereports.bmj.com/content/2012/bcr-2012-007176.abstract AB A 39-year-old man presented to the emergency department after falling downstairs after he consumed a large quantity of alcohol. On examination, he had altered mental state (GCS 14), central cyanosis and low oxygen saturation of 86%, despite 100% oxygen being administered. His arterial blood gas confirmed diagnosis of methaemoglobinaemia with a methaemoglobin percentage of 14.08. He was treated successfully with methylthioninium chloride. The patient later admitted to use of recreational poppers (amyl nitrates) the previous evening. The emergency physician is challenged by the presentation of a patient with altered mental state and unexplained low oxygen saturation with concurrent alcohol intoxication but must have a high index of suspicion for methaemoglobinaemia particularly with a history of recreational drug ingestion.