A prisoner who survived an attempt to carry out the death penalty in Tennessee, the United States, last week is conscious and speaking as she continues to receive treatment in hospital.

"Against all odds, Christa Pike is conscious, speaking, and continues to receive critical medical care," the inmate's attorneys said in a statement on Tuesday.

"Despite the severe damage she endured to her arms, she is still handcuffed and shackled to the bed. Her recovery is medically unprecedented."

Pike, who was sentenced to death for the beating, stabbing and murder of a classmate in 1995, survived two doses of the lethal injection drug pentobarbital – which her lawyers said left her arms burned and blistered.

Christa Pike not 'free of further serious risk'
"She's still in the ICU," said Dr. Joel Zivot, a professor of anesthesiology and surgery in Atlanta in neighboring Georgia, who consulted as an expert for Pike's legal team.

"She has recovered to a certain degree that she's able to be off a ventilator and able to speak, but in no way would I announce her free of further serious risk. There's still a lot of bad things that can happen here, even when everyone is doing their job well."

Tuesday's updates were the first indication that Pike's condition has improved since the failed execution attempt at a Nashville prison last Wednesday.

Her attorneys thanked first responders and medical staff who they said have "treated Christa like a human and have provided exceptional care to her" – as they prepare to go to court on Wednesday seeking to learn more about what went wrong with the lethal injection.

Pike's attorneys seeking to commute sentence
The lawyers are seeking a court order requiring the Tennessee Department of Correction to preserve evidence, including drug lot numbers, records and other information from the attempted execution.

Ultimately, they are looking to have Pike's sentence commuted to life in prison without the possibility of parole.

While Dr. Zivot said Pike's current state "bodes well for a good recovery," her attorneys warned that her prognosis is still "unclear" and said she faces "a long recovery."

"Christa is a survivor and will take recovery one day at a time," they said.

According to the Death Penalty Information Center, which publishes data and analysis on capital punishment in the United States, Pike is the first prisoner ever to survive "after being injected with lethal doses of execution drugs."