Christa Pike is awake and able to speak after surviving a failed execution in Tennessee, her lawyers say. The 50-year-old death row inmate remains in hospital receiving critical care, and her prognosis is unclear.

Pike survived two lethal injections on September 30. She was unconscious for days afterward while medical staff cleared the injected chemical from her body. Her lawyers said Tuesday that they expect a lengthy recovery.

Dr Joel Zivot, an anaesthesiologist advising Pike’s legal team, said she has been taken off a ventilator and can communicate in a basic way. He said she recalled her name but appeared not to remember the execution attempt. How much pentobarbital entered her system remains unknown, he said.

Pike was sentenced to death for murdering Colleen Slemmer with her then-boyfriend in 1995. She is believed to be the only person to survive a lethal injection.