The US has seen a spike in executions — how often are they botched?

As death row inmate Christa Pike remains in hospital following a failed lethal injection, we take a closer look at the track record for botched executions in the US.

Days after receiving two doses of the lethal injection drug pentobarbital, death row inmate Christa Pike remains alive.

Her attempted execution, which made headlines around the world, left many wondering: how often does a death penalty go badly wrong?

In the United States, the answer is: more often than you think.

And what happened to Christa Pike should concern even those who are in favour of the death penalty, according to Julian Koplin, a lecturer in bioethics at the Monash Bioethics Centre.

"If you are in favour of the death penalty, you think that in principle, [for] certain kinds of crimes … it might be proportionate justice for you to lose your own life," Dr Koplin told the ABC.

"But that's not to say it would be appropriate to torture someone.

"Executions themselves are not meant to be overly painful.

"We don't still burn people at the stake."

During that time period, the US conducted 8,776 executions, according to political science professor Austin Sarat.

Methods included lethal injection, hanging, gas, electrocution and firing squad.

According to the Death Penalty Information Center, an execution is "botched" when it departs from standard protocol.

Dr Sarat, who published a book analysing the US execution history, estimated about 3.14 per cent of them were botched.

Botched executions were those "involving unanticipated problems [that] caused unnecessary agony for the prisoner".

"With each development in the technology of execution, the same promises have been made, that each new technology was safe, reliable, effective and humane," he wrote.

"Those claims have not generally been fulfilled."

In commentary published last week, Dr Sarat also noted Pike's case was "not an isolated event".

There have been 1,492 executions via lethal injection since its adoption in 1977.

According to author Dr Sarat's analysis in 2014, 75 of 1,054 lethal injection executions conducted had gone wrong in some way.

All 27 death penalty states, along with the US military and US federal government, have authorised the method.

Lethal injection has the highest rate of being botched compared to any other execution method, according to Dr Sarat.

Prior to Christa Pike, no person has ever survived the lethal injection drug being administered.

"Seven people prior to Ms Pike had survived failed execution attempts," the Death Penalty Information Center said.

"But in all of those, the execution was called off due to difficulties setting an IV line, and no drugs were ever administered."

'Ghastly, uncomfortable' questions about death sentences

It's still unclear what exactly went wrong during Christa Pike's execution.

The Tennessee Department of Corrections team responsible for establishing intravenous (IV) lines used at least seven syringes in their attempt, according to an emergency motion filed by Pike's legal team.

At least one needle was allegedly bent "in a 90-degree angle" when it was removed.

Pike's ordeal lasted from shortly after 7pm, when the first dose was administered, to almost 9pm, when emergency services were called to the prison.

But hers is not the longest lethal injection incident on record.

In August 2022, death row inmate Joe Nathan James Jr was subjected to what a witness described as "carnage".

James suffered multiple unsuccessful attempts to establish an IV line, according to a report by human rights organisation Reprieve.

"A private autopsy later documented numerous injuries, including three unexplained cuts in Mr James left arm, deep bruising, and needle puncture wounds," the report said.

"When [James] was brought into the execution chamber, witnesses reported that he appeared to be unconscious."

One of these cuts was concluded in that private autopsy to likely be a "cutdown", a medical procedure where a deep cut exposes a vein.

Some experts have speculated the drug entered the tissue in Pike's arm, rather than entering the vein.

After arriving at a Nashville hospital, both her arms were found to be "swollen, burned, and blistered".

"Ms Pike's experts have compared pentobarbital to 'bleach' or 'Drano'," court documents said.

"It is caustic and highly alkaline and burns upon contact, including skin, tissue, and veins."

She remains intubated and on a ventilator, according to her legal team, who say it may be several days before her full condition is known.

The size of death row has declined every year since 2001, and the total population of death row is now down by more than a third compared to its peak of slightly less than 3,600 at the turn of the 21st century.

But while the population has decreased, the time spent on death row has only increased.

Inmates now spend decades on death row waiting for their execution.

In Christa Pike's case, she had been waiting more than 30 years.

According to a poll by Washington-based analytics firm Gallup, less than half of US adults aged 18-54 support the death penalty.

Support for the death penalty has been declining since it peaked at 80 per cent approval in 1994, according to Gallup's research.

A total of 44 per cent of Americans said they opposed the death penalty.

But it remains a deeply political issue, with 82 per cent of Republicans saying they are still in favour, compared with 32 per cent of Democrats.

Pike was sentenced to death in 1996 after murdering classmate Colleen Slemmer, when Pike was 18 years old.

It remains unclear whether Tennessee officials will try for another execution attempt.

But that has not stopped debate about the death penalty in the state and nationally from raging.

Tennessee Governor Bill Lee has ordered an independent review of the incident, putting the only other execution scheduled for this year on hold.

US Republican Senator Marsha Blackburn, vying to take Mr Lee's place as governor in upcoming elections, called the situation "tragic".

"While there should be a thorough review … the answer is simple," she said.

"Bring back the electric chair."

Dr Koplin said it was not that simple.

"Part of the problem [is that] most attempted methods of execution have a pretty grisly history of working out," he said.

"Including prisoners catching on fire when the electric chair has been attempted.

"They are the kind of ghastly, uncomfortable things to read about."