Warning: This article contains details that readers may find distressing

Tennessee death row inmate Christa Pike was unconscious, intubated and on a ventilator on Thursday night, after authorities failed to execute her by lethal injection, her lawyers say in court filings.

Pike, 50, was injected with two lethal doses of pentobarbital on Wednesday but remained alive. She was then sent to hospital in an ambulance.

Pike remained critically ill and was being treated at a hospital in Nashville, Tennessee.

Lawyers for Pike, who was sentenced to death in 1996 for the murder of Colleen Slemmer, are seeking to have her sentence commuted after the failed execution attempt.

Pike’s lawyers filed an emergency motion on Friday to preserve “any and all evidence” related to her botched execution.

Hospital staff are working to save her life and clear the drug – pentobarbital – from her system, the filing states.

During the execution attempt, prison officials attempted to gain intravenous (IV) access by using at least seven needles on Pike, according to her lawyers.

At one point, Pike herself offered guidance of where they could try.

“One needle was bent in a 90-degree angle when it was removed,” the filing states.

While receiving the two doses, “she could be heard crying, whimpering, and breathing loudly throughout the procedure”, her lawyers said.

“At one point Ms. Pike stated ‘my arm feels like it’s about to burst open” and at another asked “‘does this happen like that?'”

Pike’s attorneys previously warned that her conditions, including thrombocytosis (a blood-clotting condition) and small veins meant there was a risk she would experience “unnecessary” pain and suffering during a lethal injection.

In the latest filings, her lawyers allege that “at no point did any member of the execution team realise that the IV lines were not correctly placed or that the veins had blown and that the pentobarbital was, in whole or in part, entering Ms Pike’s body”.

They are requesting that all relevant physical, written and electronic evidence is preserved.