Death row inmate Christa Pike is awake and speaking after surviving a lethal-injection attempt in Tennessee last week, her lawyers said Tuesday.

Pike, 50, remains in hospital receiving critical care. Her lawyers said she was restrained to the bed and that her prognosis is unclear. Medical staff had worked to clear the injected chemical from her body after she spent days unconscious.

Two injections of pentobarbital failed to kill Pike last Wednesday. Authorities have not explained what went wrong or said whether they will attempt another execution. Criminologist Deborah Denno said she knew of no other case in which a prisoner survived an execution after a substance was injected into their veins.

Pike was sentenced to death for the 1995 murder of Colleen Slemmer, which she committed with her then-boyfriend.