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.

The authors conclude that even if lethal injection is administered without technical error, those executed may experience suffocation, and therefore that "the conventional view of lethal injection as an invariably peaceful and painless death is questionable." The Eighth Amendment of the US Constitution prohibits cruel and unusual punishment. The results of this paper suggest that current protocols used for lethal injection in the US probably violate this amendment.