Laughing gas abuse caused student’s death – coroner

Nitrous oxide abuse contributed to a student’s death, a coroner concluded.

Ellen Mercer, 24, died in hospital in February 2023, two weeks after she was left bedbound by burning her legs with a laughing gas canister.

Berkshire’s senior coroner Heidi Connor found Ms Mercer’s death was caused by her substance abuse and a blood clot.

When Ms Mercer died, possession of nitrous oxide for personal use was not illegal but it was made a class C drug last November.

Nitrous oxide is regularly used as a painkiller in medicine and dentistry. When mixed with oxygen, it is known as “gas and air”, which can help reduce pain during childbirth.

An inquest at Berkshire Coroner’s Court in Reading heard Ms Mercer inhaled two to three “big bottles” of it a day.

She was taken to Wexham Park Hospital in Slough on 9 February 2023 but died the next day.

The inquest heard a post-mortem examination found her death was caused by a bilateral pulmonary thromboembolism, deep vein thrombosis and “long-term complications of nitrous oxide use”.

Mrs Connor said that abuse was a “significant cause” for her immobility.

“Ellen Mercer’s death was caused by nitrous oxide abuse and immobility that led to the development of a pulmonary embolism,” she said.

“This case has highlighted how hugely dangerous it is to use nitrous oxide.”

An emergency medical technician who attended Ms Mercer’s home was told she had been unable to walk or go to the toilet for a fortnight after spilling a gas canister on her legs.

Michaela Kirtley said she found a “bare” room, where there was a “severely stained” duvet on the bed.

It was clear to her, she said, that Ms Mercer was vulnerable.

She had been diagnosed with bipolar disorder but authorities failed to follow up a mental health review, the inquest heard.

At the hospital, staff failed to carry out a test that could have found that Ms Mercer was at higher risk of developing a blood clot.

But Mrs Connor concluded that did not cause Ms Mercer’s death.

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