Pike had spent roughly three decades on death row after being sentenced to death in 1996 for the 1995 murder of 19-year-old Colleen Slemmer.
Her execution was scheduled for September 30, but the process was delayed for hours after a federal appeals court temporarily halted it.
The U.S. Supreme Court later lifted the stay, clearing the way for Tennessee to proceed.
Officials then moved forward with the state’s execution protocol.
But the planned execution did not end as expected.
Pike survived the first round of lethal injection.
A second round was then administered.
She survived that as well.
Eventually, medical intervention began, and Pike was transported from the prison by ambulance.
According to the Nashville Banner, she left the facility at approximately 9:28 p.m.
One of Pike’s attorneys told BBC News that she was receiving emergency medical treatment.
Dr. Joel Zivot, a professor at Emory University School of Medicine, warned that the delay before resuscitation could potentially have caused serious neurological harm.
“It’s very possible that as a consequence of the delay of the beginning of resuscitation she will have a brain injury,” Zivot told the BBC.
Witnesses inside the prison also described an execution process that appeared highly unusual.
John North, an investigative producer for WBIR-TV in Knoxville who witnessed the attempt, said observers were not able to see everything that happened.
“Very obviously, we have a lot of questions about what we saw and what we did not see, because there were moments when the blinds were down for us, and there were moments when the blinds were up for us,” North said.
He added that the process appeared not to unfold the way officials expected.
“It appeared that this did not go like they thought it was supposed to go, but we don’t know that.”
Hours later, the Tennessee Department of Correction released a statement defending its handling of the procedure.
“The Tennessee Department of Correction followed every step of the State’s lawful, established execution protocol approved by the Attorney General’s Office,” the department said.
Officials also defended the chemical used in the protocol.
“The lethal injection chemical in the protocol has consistently been effective, and the protocol does not allow for additional procedures beyond what was carried out this evening.”
The department confirmed that Pike had been taken to an outside medical facility.
Her attorneys strongly disputed the state’s characterization of what happened.
“Tonight the State of Tennessee once again failed to carry out a lawful execution,” Pike’s legal team said.
The failed execution has now drawn renewed attention to the mechanics of lethal injection itself.
One of the central questions is why a drug intended to cause death may fail to produce the expected result.
Pentobarbital is a barbiturate that, at sufficiently high doses, can suppress brain activity, breathing, and cardiovascular function.
But anesthesiology experts have previously pointed out that the drug is only effective if it actually reaches the bloodstream in the intended concentration.
Problems with intravenous access can dramatically change what happens.
Dr. Daniel Medel, the anesthesiology expert behind the YouTube channel Danesthesia, has previously discussed how failures in IV placement, drug delivery, staff training, or preparation can turn an execution into a prolonged and unpredictable procedure.
“Several botched executions highlighted how fragile these protocols can really be,” Medel said.
He pointed to the 2014 execution of Clayton Lockett in Oklahoma as one of the most notorious examples.
During that execution, an IV line failed.
As a result, the drugs were not administered properly.
Lockett showed visible signs of distress and died 43 minutes after the first drug was administered.
“Investigations later revealed critical failures in IV placement, poor staff training, and breakdowns in protocol,” Medel explained.
The case became one of several that intensified debate about whether lethal injection can reliably produce a rapid and painless death.
Medel also discussed the execution of Dennis McGuire, who was put to death using a combination of midazolam and hydromorphone.
McGuire reportedly gasped and made snorting sounds for between 10 and 15 minutes before being declared dead.
That execution led to further questions about whether the drug combination could consistently produce unconsciousness and death without prolonged suffering.
Another widely scrutinized execution involved Joseph Wood in Arizona in July 2014.
Wood was also given midazolam and hydromorphone.
His execution lasted nearly two hours.
According to reports cited by Medel, officials administered a total of 15 doses before Wood was pronounced dead.
For Medel, those cases demonstrate how much depends on the technical details of drug delivery.
“Each of these cases revealed the same problem,” he said.
“When IV access, training, or drug preparation fail, the outcome isn’t quiet or quick.”
Instead, he said, the result can become “unpredictable and often visibly painful.”
In Pike’s case, questions remain about exactly why the procedure failed.
Was there a problem with IV access?
Did enough pentobarbital enter her bloodstream?
Was the drug delivered properly?
How long did she remain without adequate medical intervention?
And what happened during the periods when witnesses could not see into the chamber?
Those questions have become even more urgent because Pike survived not one, but two rounds of injections.
The fact that she was ultimately transported to a hospital means the state’s execution attempt ended not with a declaration of death, but with emergency medical treatment.
For now, Pike remains hospitalized as attorneys, medical experts, witnesses, and state officials continue examining what happened inside Riverbend Maximum Security Institution.
The failed execution has also renewed a much broader debate about lethal injection protocols and whether states can reliably carry them out without complications.
What was supposed to be a final, controlled procedure instead ended with an ambulance leaving the prison — and with more questions than answers about how an execution involving a powerful barbiturate could fail twice.