Christa Pike remains critically ill in a Nashville hospital on a ventilator following a failed execution attempt on Wednesday, with her medical prognosis still unclear, her lawyer said Sunday.

Stephen Ferrell told CNN that doctors were still working to clear two doses of the drug pentobarbital from Pike's body. He said Pike, 50, has not regained consciousness and may not for several days. Ferrell, who receives updates through Pike's medical power of attorney rather than directly from doctors, has not visited her in the hospital, which he said is under guard.

Pike was sentenced to death in 1996 for the 1995 murder of Colleen Slemmer in Knoxville, Tennessee. She was 18 at the time. Pike and her then-boyfriend Tadaryl Shipp beat, tortured and killed the 19-year-old Slemmer.

Wednesday's execution was Pike's second failed attempt. Authorities have not explained what went wrong or said whether they will attempt execution again. Tennessee Governor Bill Lee suspended all executions for the remainder of the year. The state's prisons director announced his resignation following the failed execution.

Pike's lawyers had previously warned that her medical history posed risks during lethal injection. She has thrombocytosis, a blood-clotting condition, and small veins that could cause unnecessary pain and suffering.

Ferrell called on the governor to commute Pike's death sentence to life in prison. He noted Pike spent over 30 years incarcerated, most of it in solitary confinement, and said "We don't know right now and we may never know what sort of torture she endured during her failed execution." He added that if Pike recovers, there may be questions about her competence and that the Tennessee attorney general's office has not indicated its intentions regarding another execution attempt.

Colleen Slemmer's mother, May Martinez, traveled to Nashville for the execution and told local outlet WJXX that she broke down in tears when it failed. Martinez, who supported Pike's death sentence, said "the state owes me a big apology."

The Department of Correction defended lethal injection protocol, stating "the protocol does not allow for additional procedures beyond what was carried out."