Christa Pike remains on a ventilator after failed Tennessee execution

Convicted murderer Christa Pike remains unconscious and on a ventilator in hospital after Tennessee prison officials botched her execution on Wednesday night.

Doctors are currently working to clear the lethal sedative pentobarbital from her system, but her lawyers warn she may have suffered permanent brain injury due to delays in resuscitating her.

During the execution attempt at the Riverbend Maximum Security Institution in Nashville, prison staff used at least seven needles to try and establish intravenous lines, her legal team said in a court filing. Although they eventually administered two doses of pentobarbital, the drugs failed to stop her heart.

Instead, the sedative reportedly leaked into the surrounding tissue of her arms. Her attorney, Randy Spivey, said her right arm turned purple and she suffered severe chemical burns. Witnesses said she could be heard crying, whimpering and breathing heavily behind the execution chamber's curtain.

Dr Joel Zivot, an anaesthesiologist advising her defence, said the blisters on her arms show the veins had "blown" under the pressure. Because the drug did not enter her bloodstream, the concentration was never high enough to kill her.

This outcome was exactly what Pike’s lawyers had warned the state about. In January, they filed a lawsuit pointing out that she suffers from thrombocytosis, a blood-clotting disorder, and has exceptionally small veins that make line placement hazardous. Her former lawyer, James Crowson, said the warnings made the horrific outcome entirely predictable. "I knew that there were a number of defence filings saying that she had compromised veins," he said, adding that the state has a history of ignoring medical science when drafting execution rules.

The political fallout was immediate. Tennessee Governor Bill Lee has suspended all executions in the state for the rest of the year and ordered an independent review. Frank Strada, the commissioner of the Tennessee Department of Correction, announced he will resign later this month. Death penalty lawyers noted that this is the fifth execution Strada has botched during his career in Tennessee and Arizona.

State officials have defended their actions, saying prison staff followed the execution protocol to the letter. However, the state’s guidelines contain no instructions for what to do if a prisoner survives a second dose of pentobarbital.

Pike, now 50, was sentenced to death in 1996 for the torture and murder of 19-year-old Colleen Slemmer at a camp for troubled youth in Knoxville. Her accomplice, Tadaryl Shipp, was 17 at the time and was spared the death penalty because of his age; he is currently serving a life sentence.

It remains unclear whether Tennessee will attempt to execute Pike again if she survives. Her lawyers have already filed an emergency motion to preserve all physical evidence from Wednesday’s failed procedure, and are preparing to ask Governor Lee to commute her sentence to life.