We were able to analyze only a limited number of executions. However, our findings suggest that current lethal injection protocols may not reliably effect death through the mechanisms intended, indicating a failure of design and implementation. If thiopental and potassium chloride fail to cause anesthesia and cardiac arrest, potentially aware inmates could die through pancuronium-induced asphyxiation. Thus the conventional view of lethal injection leading to an invariably peaceful and painless death is questionable.
In other words the effect of thiopental as it is used in execution protocols may not be strong or long lasting enough to eliminate awareness of the pancuronium-induced respiratory paralysis or the intense pain resulting from injection of concentrated potassium chloride.
The article also cites eyewitness accounts suggesting inmates’ suffering and points out that execution by lethal injection doesn’t have nearly the research underpinning or ethical oversight that is applied to animal euthanasia. This paper may result in increased pressure for states to open their execution records and may be a stimulus for legal challenges against execution by lethal injection.
Now for some personal disclosures and reflections. I oppose capital punishment. I also, as regular readers know, believe that scientific discussions can be corrupted when mixed with political debate. When such discussions overlap, as they inevitably must, safeguards are necessary. First, while science can legitimately inform political discussions (in the case of lethal injection, the authors clearly show us that we had better understand a little pharmacology before we can argue about whether it’s humane) it should not be the other way around. Second, appropriate disclosure of significant political affiliations or leanings is essential. To the credit of PloS Medicine appropriate disclosure seems to have been made. We are informed that one of the authors practices capital defense, another has been a paid expert in death penalty litigation and all the editors at PLoS Medicine oppose the death penalty. Other journals should take note.