Updated

A British teenager was left permanently paralyzed from the waist down after an epidural anesthetic was left in her spine for too long after a routine operation to remove gallstones, a hospital has admitted.

Sophie Tyler, 17, from Newport, South Wales, was 14 when staff at Birmingham Children's Hospital left the painkiller in her back for two days, Sky News reported Wednesday.

"My daughter's life has completely changed as a result of what happened," said Sophie's mother Sue. "From being an outgoing teenager, her life has altered overnight and we have all had to come to terms with what has happened."

Hospital staff had been told that numbness had spread to both Sophie's legs and she was unable to move her feet, but the anesthetic was not removed until 48 hours after her operation -- by which time it had entered her spinal cord and damaged her membrane.

"Other than suffering from gallstones, Sophie was a very healthy and active young girl," said the family's lawyer Tim Deeming.

He added, "At the age of 14 to be told the news that you will never walk again is unimaginable and to discover that mistakes were entirely avoidable, has been incredibly hard for them to cope with."

In a statement, Dr. Vin Diwakar, chief medical officer at the hospital, said, "We are deeply sorry for the unimaginable distress we have caused Sophie and her family as a result of the care she received at our hospital three years ago."

Deeming said that the hospital's full admission of liability now paves the way for a settlement that will provide Sophie with the financial support she will need to pay for specialist care and equipment for the rest of her life.

Click here to read more on this story from Sky News.