By Dan Warburton & Joe Smith
A student who died after becoming a habitual nitrous oxide user went through more than 200 canisters a day, an inquest heard.
Ellen Mercer's death was related to “long-term complications of nitrous oxide use,” the coroner said. Ellen, 24, told her boyfriend not to call an ambulance as it “kills her buzz” when she began suffering leg and back pain. She was left unable to walk or go to the toilet for two weeks, Berkshire coroner’s court was told.
Paramedics raced to the business student’s home to find Ellen with a freeze burn on her leg where a canister had fallen when she collapsed. Her boyfriend revealed she took two to three 600g bottles of nitrous oxide - known as hippy crack \- a day.
The court heard this is the equivalent to around 225 of the regular 8mg metal canisters that are used for laughing gas. She was treated by medical staff at Wexham Park Hospital Emergency Department, but died at 12.52am on February 10.
Senior coroner Heidi Connor told the inquest that “part of her cause of death” related to “nitrous oxide gas”, also known as laughing gas. Government figures show that between 2001 and 2020, there were 56 registered deaths involving nitrous oxide in England and Wales - 45 of them since 2010.
The inquest heard that a post-mortem report found Ellen’s death to have been caused by bilateral pulmonary thromboembolism, deep vein thrombosis, and “long-term complications of nitrous oxide use”.
Emergency worker Michaela Kirtley attended Ellen’s home on February 8. When she arrived at the scene, she was shown to the bedroom by Ms Mercer’s boyfriend. Ms Kirtley told the inquest today: “I took notice of the room. There were no sheets on the bed at all. There was just the duvet, severely stained. The room was bare.”
She said the scene made it clear to her that she was dealing with a “vulnerable person”. She said Ellen “was talking as normal”, and the only one of her vital signs that was outside the normal range was her heart rate, which could have been due to anxiety.
Ellen, from Gerrards Cross, Bucks., told her that she had burned her legs after spilling a gas canister on them, Ms Kirtley said. She said the 24-year-old looked six months pregnant. She checked the wounds on Ellen’s legs, which she described as “pus-y”.
Ellen’s boyfriend showed her a box of gas canisters, which she identified as nitrous oxide. Ms Kirtley said: “I had never seen such big bottles.” She told the inquest that the canisters were 600g and that Ellen’s boyfriend said she took “two to three bottles” per day, but had slowed down in the last couple of weeks.
At the time of the student’s death, possession of laughing gas with the intent of getting high was not illegal. It was banned by the Government, and made a Class C drug, in November 2023. In her conclusions, senior coroner Heidi Connor said: "Ellen Mercer's death was caused by nitrous oxide abuse and immobility that led to the development of a pulmonary embolism."
Ms Connor added: "This case has highlighted how hugely dangerous it is to use nitrous oxide. It is the nitrous oxide which has been the significant cause of her immobility." The inquest also heard that Ms Mercer had been diagnosed with bipolar disorder, but local services had failed to follow up on her mental health review.
