Two of the three drugs used in lethal injection are not administered in a way that reliably produces painless death for inmates, leaving at least some to die of suffocation and be conscious enough to realize it, according to a new analysis of executions in California and North Carolina.

Reviewing the cases of 41 inmates dating back to 1984, the researchers found that the dose of anesthesia given at the start of an execution varied widely and was often short of the amount needed to keep an inmate unconscious.

They also concluded that the chemical intended to induce cardiac arrest did not always stop prisoners’ hearts.

“The argument that’s always been given about lethal injection is that in theory, a well-trained person could give it humanely,” said Deborah Denno, a professor at Fordham University School of Law who has studied lethal injection for 15 years. “This casts doubt on even that.”

Seeking a better way

The study, published Monday in the Public Library of Science journal PLoS Medicine, provides badly needed scientific data for a debate that has been largely devoid of hard evidence regarding the medical underpinnings of lethal injection.

Twelve states have put executions on hold in large part due to concerns about the constitutionality of lethal injection. California Gov. Arnold Schwarzenegger and state Attorney General Jerry Brown intend to recommend reforms by May 15.

The study is “shedding light on a process that should have been examined a long time ago,” said Michael Rushford, president of the Criminal Justice Legal Foundation, a Sacramento, Calif., advocacy group that favors the death penalty.

While he doubted many of the study’s conclusions, he supported the idea that lethal injection may be too problematic to preserve. “The real issue should be, ‘Is this the best way to do this?’ Let’s get some doctors together and say, ‘If you were going to put your mother down, how would you do it?'”

Origin

Execution by lethal injection was originally formulated in 1977 by an Oklahoma state legislator who opposed capital punishment and worked with the state medical examiner to devise a humane alternative to electric chairs and firing squads.

They developed a regimen of three powerful drugs – the sedative sodium thiopental to make the inmate unconscious, the muscle relaxant pancuronium bromide to induce paralysis, and potassium chloride to stop the heart.

Each was supposed to induce death on its own, and the combination was intended to provide redundancy. Though the regimen was never scientifically tested, it was widely adopted by other states and first used in Texas in 1982.

Thirty states rely on lethal injection to carry out executions, and all but New Jersey use the three-drug regimen.

But acceptance of lethal injection as a humane method of execution began to crumble. Inmates filed suit, arguing that it violated the Constitution’s prohibition against cruel and unusual punishment.

Executions on hold

U.S. District Judge Jeremy Fogel in San Jose put all California executions on hold last year after a challenge from San Quentin death-row inmate Michael Morales.

So far, 901 inmates have been executed by lethal injection in the United States, according to the Death Penalty Information Center, a Washington group that opposes capital punishment. Ohio is scheduled to execute James Filiaggi this morning.

The new study focused on executions in California and North Carolina because those states had the most complete information available.

The authors included an anesthesiologist, a pharmacologist, a molecular biologist, a veterinarian, an attorney and a historian. Many have described themselves as death penalty opponents.

Several of the researchers worked together on a 2005 study that found prisons routinely failed to administer enough anesthesia to keep inmates unconscious throughout their executions. They based their conclusions on the concentration of anesthesia measured in the bloodstream at post-execution autopsies.

Findings

In the new study, the researchers focused what they believed was a key problem: that inmates were given uniform amounts of anesthesia regardless of their body weight or other factors, such as their tolerance for barbiturates. North Carolina uses 3 grams of thiopental, while California requires 5 grams.

Because North Carolina records included the weight of each inmate, the researchers were able to calculate the dosages in that state, which ranged from 10 to 45 milligrams per kilogram.

They calculated that states such as Virginia that use 2 grams of thiopental were administering doses between 6.6 and 30 milligrams per kilogram.

Those dosages are below what is necessary to have a 50-50 chance of euthanizing many laboratory animals such as rabbits, dogs and rats, according to the study.

In some cases, the dosage overlapped with the 3 to 6.6 mg per kg dose of thiopental used to anesthetize patients at the outset of a surgical procedure. But in an operation, more anesthesia would be administered throughout the procedure to keep the patient under.

In an execution, “there may or may not be enough anesthetic on board for the whole process to do its thing,” said Dr. Leonidas Koniaris, a surgical oncologist at the University of Miami Miller School of Medicine and lead author of the study. “There’s a window for at least part of the process where they may be quite uncomfortable.”

Without sufficient anesthesia, inmates would feel as if they’re being strangled while the pancuronium bromide asphyxiates them by bringing on paralysis.