DEATH PENALTY [+]Enlarge Credit: Associated Press

Shortly before 6:30 pm on April 29, an Oklahoma prison official injected a sedative into an intravenous line in the groin of Clayton D. Lockett. Lockett was to be executed for shooting 19-year-old Stephanie Neiman 15 years ago, then watching as two accomplices buried her alive.

After the sedative injection, Lockett was declared unconscious, and he started receiving two more compounds—one to stop his breathing and the other to stop his heart. At 6:36 PM he started writhing, grimacing, and lifting his head and shoulders off the gurney to which he was strapped, according to eyewitness accounts. At 6:50 PM, prison officials stopped the execution. Shortly thereafter, Lockett died of an apparent heart attack.

This and other recent botched executions have helped thrust lethal injections into the spotlight. The latest in a line of efforts to bring convicted felons to a quick death—the U.S. since 1900 has also used hanging, firing squads, electrocution, and lethal gassing—lethal injections are often thought of as a painless medical procedure, far more humane than its predecessors.

But whether lethal injection is as humane as advertised is a murky question. Medical involvement is hard to pin down but certainly less than the public recognizes. And problems with executions seem only to be mounting as supply challenges force execution teams to turn to untested drug providers and change protocols on the fly.

The current situation is “chaos,” says Deborah W. Denno, a law professor at Fordham University who has researched and written about capital punishment extensively. “The more information that states reveal, the more we realize that they don’t know what they’re doing,” Denno says.

The first lethal injection protocol was suggested by a medical examiner and adopted by Oklahoma in 1977; other states quickly followed suit. The procedure was supposed to take just a few minutes and included three compounds used in sequence, similar to the method used for Lockett.

The first compound was thiopental sodium, at the time a commonly used anesthetic that depresses central nervous system activity. In executions, thiopental was used to make the condemned person unconscious. It was to be followed by pancuronium bromide, which inhibits muscle contraction and stops breathing; it was used medically to enable intubation and keep patients still during operations. The final compound was potassium chloride, an electrolyte that alters the voltage potential across ion channels and is used medically to stop the heart for cardiac procedures after a patient is placed on a heart-lung machine.

For the three-chemical protocol to be considered humane, it is essential for the person being executed to be adequately anesthetized before the other two compounds are administered. If the person is not unconscious, then he or she would experience suffocation from the pancuronium and burning from the potassium chloride. Once the pancuronium is administered, because the person is unable to move, it can be difficult to tell whether they are still adequately anesthetized.

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That makes the anesthetic dose particularly critical. In medical applications, generally doses of the drugs in question are determined by a combination of weight and a patient’s age and physical condition, says Ronald Pearl, chair of the department of anesthesiology at Stanford University School of Medicine. Available execution protocols instead tend to prescribe fixed amounts, regardless of an individual’s physiology. Law professor Denno surveyed lethal injection protocols in 2005 and found a range of approaches in the 13 states that revealed specific lethal injection chemical quantities (Fordham Law Review 2007,76, 49). Alabama and Tennessee specified only volumes, such as 100 and 50 mL of pentothal, respectively. Other states merely gave a weight, such as Kentucky with 3 g and Washington with 2 g thiopental. Only three—Connecticut, Maryland, and Texas—managed to specify both weight and concentration of all three compounds in the protocols.

Although 2–3 g of thiopental is assumed to be enough to ensure deep unconsciousness or death, one analysis suggests that it’s not (PLoS Med. 2007, DOI: 10.1371/journal.pmed.0040156). Another study of postexecution blood levels of thiopental in 49 people indicated that 43 had less than that required for surgery and 21 may have been conscious (Lancet 2005, DOI: 10.1016/s0140-6736(05)66377-5).

The medical establishment’s stance on executions also means that relatively inexperienced people are likely administering lethal injections. “I think that when people talk about botched executions, generally the botched part comes from how the drugs were administered, not so much that the drugs don’t work,” says Pearl, who has never been involved in an execution.

Although some states do require that execution teams include people with medical training, the minimum qualifications may be met by a certified medical assistant, phlebotomist, emergency medical technician, paramedic, or military corpsman with one year of experience, as in Ohio. Inexpert technicians may have trouble placing an intravenous line, especially in drug abusers who may have scarred veins that are particularly vulnerable to collapse. And sometimes “people have great big veins that you think you could hit from across the room, but the veins roll,” says Donna L. Seger, a professor of clinical medicine at Vanderbilt University Medical Center who has not been involved in executions. She also notes that it can be easy to nick the edge of a vein.

But even when doctors go against ethical guidelines and participate in lethal injection, things can go wrong. In Lockett’s case, for example, an Oklahoma Department of Corrections timeline says that an unidentified phlebotomist and doctor spent nearly an hour trying to find a usable vein in Lockett’s arms and feet before placing an intravenous line in his groin. The vein in his groin then failed, leaving the administered compounds to be absorbed into nearby tissue or to leak out. The Oklahoma Court of Criminal Appeals delayed the state’s next execution until Nov. 13 while officials investigate what happened to Lockett and review execution procedures.

Overall, lethal injections are botched at a higher rate than other methods—7.1% versus 3.1% overall for executions conducted from 1900 to 2010 in the U.S., according to a study led by Austin D. Sarat, a professor of law, jurisprudence, and social thought at Amherst College. The analysis is published in his 2014 book “Gruesome Spectacles: Botched Executions and America’s Death Penalty.”

States have found it increasingly challenging to perform problem-free lethal injections in the past few years. The difficulties are driven by lack of drug availability. Thiopental, for example, is an older medication that has largely been replaced in anesthesia by propofol. Hospira stopped making thiopental in the U.S. in 2010 and ceased production entirely in 2011. Some states started importing foreign-made thiopental that was not approved by the Food & Drug Administration. But a court ruled last year that the agency could not allow the practice.

In response, states have tried a number of different strategies. A common one was to switch to pentobarbital, either as the first of the three-compound combination or alone—pentobarbital also suppresses breathing and can be lethal on its own.

More recently, some states have turned to midazolam hydrochloride, a benzodiazepine commonly used medically as a preanesthetic sedative to reduce anxiety and induce amnesia. At a high dose, it will make someone unconscious. Florida and Oklahoma have used midazolam as the first drug in three-compound lethal injection protocols; it was the sedative that Lockett received. They have also replaced pancuronium with vecuronium.

Ohio has also begun using midazolam, but in a two-compound combination with the opiod hydromorphone hydrochloride. Like midazolam, hydromorphone will depress respiration; combined, they will do so at a lower dose, says Frank H. Burton, a professor of pharmacology at the University of Minnesota, Twin Cities, and president of Minneapolis-based drug firm Psyncretis. He has never been involved in an execution.

The first time the two-compound protocol was used was on Jan. 16 for Dennis McGuire, who was sentenced to death for raping and killing Joy Stewart in 1989. The execution took 25 minutes and McGuire struggled and made snorting sounds, according to eyewitness reports. The state plans to increase the doses of the compounds in future executions.

But even switching to compounds commonly used in current medical practice hasn’t solved execution teams’ supply problems. Several manufacturers of the drugs in question—among them Lundbeck, Akorn, Hikma, Fresenius Kabi, and Hospira—have implemented distribution systems designed to prevent their products from being used for capital punishment.

At least some states—including South Dakota, Missouri, and Texas—have now turned to compounding pharmacies for supplies. It’s unclear what, exactly, compounding pharmacies are doing in this role, whether they’re just serving as a middleman for prisons to get past manufacturer restrictions or whether—and how—they’re creating formulated compounds from scratch. Critics of the use of compounding pharmacies question whether such pharmacies are adept at quality control.