Peer-reviewed studies identifying problems in the design and implementation of lethal injection for execution.

• Author: Zimmers, Teresa A.
• Position: The Lethal Injection Debate: Law and Science

ABSTRACT

Lethal injection was designed and carried out without any research at all. There is no evidence that any literature searches, animal modeling, clinical studies, or investigations of veterinary practice were performed prior to the first lethal injection execution. The paucity of objective information on drug action and mechanism of death in lethal injection belies the assurance of expert testimony in lethal injection litigation. Here we review two peer-reviewed studies on lethal injection for execution in which we present evidence that lethal injection does not affect death through the mechanisms intended, that thiopental may be insufficient to assure anesthesia, and that death might be affected through pancuronium-induced asphyxiation. We conclude that failures in protocol design and implementation indicate that the conventional view of lethal injection as an invariably painless death is flawed.

1. EXECUTION BY LETHAL INJECTION

   Lethal injection for execution has largely replaced other modalities for the implementation of the death penalty in the United States. Public repugnance and legal challenges to execution by cyanide gas and electrocution led to the development of lethal injection as an ostensibly more humane method of judicial killing. (1) Lethal injection as the mode of execution has been imposed in 929 of the 1099 executions in the United States from the re-establishment of the death penalty in 1976 to March 8, 2008. (2) Lethal injection involves the administration of three chemicals into the condemned inmate: thiopental sodium, a barbiturate anesthetic; pancuronium bromide, an agent that causes muscle paralysis including respiratory arrest; and potassium chloride, a depolarizing agent intended to stop cardiac activity. Modifications of the United States' lethal injection protocols have also been adopted world-wide. (3)

   The design of a pharmacologically-based method to impose execution in the United States has generally been attributed to a desire to find a less expensive and more humane method than electrocution. (4) Some have also contended that the protocol provides the appearance of a quiet, peaceful death, not dissimilar from falling asleep. If lethal injection indeed reliably assured a painless death, the method might comport with some judicial opinions measuring execution methods against "evolving standards of decency that mark the progress of a maturing society," and prohibiting punishments that involve "the unnecessary and wanton infliction of pain," "torture or a lingering death," or which do not accord with "the dignity of man." (5) Other justices and legal scholars have questioned and even objected to the lethal injection protocol's resemblance to a medical procedure with anesthesia, arguing that such an effort to minimize pain and to cloak execution in the garb of medicine reduces the retribution aspect of execution and confuses the public. (6)

   Although lethal injection gives the appearance of a medical procedure, no research whatsoever--clinical, veterinary, medical literature search, or other--was ever performed prior to the crafting of the initial Oklahoma legislation or the first lethal injection in Texas. (7) The designer of the protocol, Jay Chapman, then an Oklahoma medical examiner, was guided by his experiences as a patient. (8) He intended each of the drugs to be lethal individually and that the combination would provide redundancy. Dr. Stanley Deutsch, then chairman of anesthesiology at an Oklahoma University Medical School arrived at a similar design. (9) Each proposed the combination of an ultra-short acting barbiturate and a paralytic; potassium chloride was not written into the statute but was added later.

   The use of pancuronium bromide in the lethal injection protocol most often results in rapid paralysis of the inmate, rendering him motionless in death. The appearance of restful sleep, however, would mask extreme pain and suffering if the inmate were aware. If the thiopental were inadequate to assure anesthesia, then the inmate would suffer the sensations of paralysis and suffocation induced by the pancuronium and intense burning and cardiac arrest induced by the potassium chloride. Such pain and suffering may well violate the Eighth Amendment prohibition against "cruel and unusual punishment." This is no mere hypothetical consideration; rather eyewitness testimony, evidence presented in litigation, along with data and interpretation published in scientific journals indicate there are significant problems with lethal injection, both in terms of the methodology by which it is imposed as well as the drug design. This Article discusses peer-reviewed manuscripts in the scientific literature examining the lethal injection protocol.

2. SCIENTIFIC PEER-REVIEW

   Peer-review, the process of subjecting an author's work to criticism and evaluation of other experts in the same field, plays a central role in what research is published. Journal editors screen submitted manuscripts for quality and interest by subjecting them to the criticism and evaluation of other experts in the same field to ensure that manuscripts meet appropriate research, statistical, scholarship, and journal criteria. When manuscripts undergo peer review, authors receive rigorous, detailed professional critiques from the reviewers either anonymously or openly, and are required to respond to the criticism by performing additional experiments, re-evaluating data, highlighting weaknesses, and/or incorporating other citations or interpretations into manuscript. Editors and reviewers then together decide whether the data in the revised manuscript supports the authors' interpretations and whether the results are of sufficient interest to merit publication. Publication in peer-reviewed journals provides other investigators the necessary information to repeat, reanalyze, and build upon prior data and in that manner grow the knowledge base in the field. In the...