THE parents of a girl who died after a freak reaction to drugs used during a routine operation have paid tribute to their "lovely, lively little girl".

Sarah Peacock died hours after a routine endoscopy at Bishop Auckland General Hospital on September 29, last year.

The 17-year-old had been admitted for the exploratory procedure after suffering stomach problems.

Despite surviving several operations during her childhood, for problems associated with a developmental disorder she had, on that day, she suffered a fatal reaction to the anaesthetic drug used.

Sarah, from Weardale Walk, in Shildon, County Durham, was born with the rare genetic disorder Cornelia de Lange syndrome.

The condition affected her physical and mental development, leaving her with severe learning difficulties, no speech and impaired growth.

By the age of 17, she was only 3ft 6in - but her parents John and Lynn describe her personality as huge.

Mrs Peacock said: "Sarah was a lovely, lively little girl - small in stature, but big in personality.

"Everybody who got to know her loved her but they all called her a little minx.

"She was like a mischievous child - always running, climbing, into everything and nipping people for a reaction, which really made her laugh."

Mr Peacock said she is missed every day by her family, sisters Emma, 13, Tori, 22, and friends from The Oaks School, in Spennymoor.

An inquest, held at Chester-le- Street on Tuesday, heard that medics had no reason to predict Sarah's body would reject the standard anaesthetic profonol, having shown no side-effects to it in the past.

Pathologist Dr Jennifer Hamilton said the drug occasionally leads to complications, but usually just in children using it long-term.

She said: "It has never been recorded in anyone who had it for such a short period of time, the whole procedure lasted only 22 minutes. This is incredibly rare.

"It may be the syndrome she had included a cell abnormality that led to the severe reaction."

Recording a verdict of misadventure, Coroner Andrew Tweddle said the reaction was totally unexpected and difficult to explain.

Mrs Peacock said: "She never had problems with anaesthetics before - she would always pull round and go home the same day.

"But that time she didn't come home.

"We don't blame anyone. Everyone at the hospital was always great with us and did all they could, but it is awful to have no real explanation why she died."