Death row inmate Christa Pike has been released from a hospital in the United States and sent back to prison where she will continue receiving medical care following her botched execution attempt in Tennessee, her attorneys say.

Pike was discharged from a local hospital on Saturday and is now at the Debra K. Johnson Rehabilitation Center, where she has been housed for more than 30 years, said attorneys Stephen Ferrell and Luke Ihnen from Federal Defender Services of Eastern Tennessee, and Randy Spivey and Kelly Gleason from the Tennessee Office of the Post Conviction Defender in a joint release.

Pike, sentenced to death for a 1995 murder, awoke "angry and confused" in the hospital last week with a long recuperation ahead after surviving the attempted execution on September 30, her lawyers said on Wednesday.

They previously believed she could be brain-dead.

Pike, 50, had been taken from the execution chamber to a Nashville hospital, unconscious, critically ill and ‌with severe arm injuries after two injections failed to kill her at the Riverbend Maximum Security Institution.

A Tennessee judge last week ordered state officials to preserve all evidence related to their failed attempt to execute her, a development one of her lawyers called the "first of many steps to preserve and enforce her constitutional rights."

Tennessee Governor Bill Lee suspended all executions for the rest of the year while investigators look in to the botched execution of Pike and a similar failure involving Tony Carruthers in May, when prison officials were unable to set up intravenous lines.

Pike was sentenced to death for her role as a teenager in the 1995 torture and murder of her 19-year-old schoolmate Colleen Slemmer.

She is the first person known to have survived a "completed execution attempt" in the US, her lawyers say, calling it a violation of the Constitution's prohibition on cruel and unusual punishments.