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How Lethal Injection Works

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Virtually all of the 32 American states that allow the death penalty rely on a deadly chemical cocktail to slowly and quietly kill the condemned. But America has found itself running dangerously low on sodium pentothal, the injection's primary ingredient, after the only US supplier stopped making it. So how are we supposed to kill the 3,000-plus inmates currently on Death Row? Guillotine? Actually, the doctor who developed lethal injections in the first place thinks it might be more humane.

Whether you personally agree with the practice or not, capital punishment has long been a fundamental component of government. From the founding of the earliest city-states, the rule of law has been built on the state-sanctioned execution of a society's most heinous transgressors. While the method of execution has changed over the millennia, its message remains the same: government—and only government—has the right to take the lives of its citizens.


But while the number of nations that maintain this stance has shrunk to just 20—100 others, 51 percent of the world total, have sworn off the practice—America remains steadfast in its use of the death penalty. According to the most recent records available from the U.S. Department of Justice, some 3,175 inmates in 32 states and throughout the federal prison system are on Death Row. Since 1977, when the death penalty was reinstated at the federal level, more than 1,200 inmates have been executed, with 43 put to death in 2012 alone. Only China (2000), Iran (314), Iraq (189), and Saudi Arabia (90) executed more people last year than we did.


How Lethal Injection Got Its Start

Between death by electrocution, hanging, firing squad, gas chamber, and beheading, capital punishment has always been a dirty, brutal affair. Lethal injection has risen to prominence and become the near-exclusive method of execution in America, due to its reputation of being less painful and more humane than other methods.

The concept was originally proposed in 1888 by New York doctor Julius Mount Bleyer, though his idea never came to fruition. It wasn't until 1977 that an Oklahoma state medical examiner named Jay Chapman devised the current three-drug cocktail, known as Chapman's Protocol. This method first injects an ultra-short-acting barbiturate in combination with a pair of chemical paralytics, which suppress respiratory and cardiac functions. The protocol was quickly adopted by Oklahoma, then Texas. In 2004, 38 of the 39 states that maintained the death penalty used Chapman's Protocol. The practice has also spread abroad, becoming the preferred method utilized by China, Thailand, Guatemala, and Taiwan.


The Procedure

After an inmate's appeals have been exhausted, an execution order is ordered by the court and the date of execution is set. In the weeks preceding the date, in California at least, the inmate is interviewed by a number of prison staff including psychiatrists, clergy, and social workers who generate pre-execution reports based on their interactions. Additional sanity review requests can be filed at that time as well. In the days and hours leading up to the scheduled execution, the inmate is allowed priority visiting rights for family, spiritual advisers and legal representation, given a fresh pair of cloths and EKG monitor, his last meal, and last rites before being ushered into the execution chamber and strapped to a gurney.


IV lines are inserted into two usable veins (one as a backup), and a slow saline drip is started. Once the inmate is given the opportunity for some last words to the witnesses seated adjacent to the execution chamber, the warden issues the execution order and the process begins.

Chapman's Protocol relies on a trio of powerful drugs, each individually lethal in its administered dose—and even more so when used together. Five grams (14 times the .35g recommended dosage) of sodium pentothal is administered first. This fast-acting barbiturate is typically used as an anesthetic for medically inducing comas, and will typically render the condemned inmate unconscious within ten seconds.


Following a saline flush of the IV line, 100mg of Pancuronium bromide is injected next. This drug is a non-depolarizing muscle relaxant that blocks the action of a specific muscle receptor site that prevents the fiber from contracting, effectively paralyzing the inmate and arresting his breathing. After a final IV flush, the inmate receives an injection of 100 mEq of potassium chloride. Potassium is an electrolyte used by our bodies use to help transmit electrical signals among our neurons and muscles. While sodium and chloride, the other two primary electrolytes, exist primarily in our extra-cellular fluid, 98 percent of the potassium in our bodies resides within our cells.

That said, when someone then injects large amounts of potassium into your bloodstream, it throws off the body's electrolytic balance and causes hyperkalemia. This condition lowers the resting electrical potential of the heart muscle cells, preventing them from repolarizing and refiring—effectively stopping the heart and inducing cardiac arrest. Once the EKG registers asystole, a physician will inspect the inmate and declare an official time of death.


Building a Better Killing Machine

This three drug cocktail, though touted as more humane than other execution methods, isn't without its detractors. A number of studies have intimated that, if the anesthesia is inadequate, inmates would be aware and suffering as their hearts and lungs stop functioning.


The three-drug mix can also be difficult to administer if the inmate has severe cardiovascular degeneration. After the failed execution attempt of convicted kidnapper/rapist/murderer Rommell Broom, the Ohio state penal system dropped the Pancuronium and potassium entirely and began simply injecting condemned inmates with 5 g of Sodium thiopental only, still enough to kill them. A number of other states have since also switched to the single drug regimen.

The problem with the Ohio protocol, as the single drug method is known, is that the only American company that manufactures it, Hospira, recently moved its headquarters to Italy. Under Italian law, the company was barred from exporting the chemical to the US unless it could prove that it would not be used in lethal injections—and thus, the supply of sodium thiopental in America is dwindling. The 11 states that continue to use this method have begun looking into using Pentobarbital, the stuff vets use to euthanize animals, as an alternative.


Ironically, even Dr. Chapman himself is in favor of discontinuing the use of his protocol. As he told CNN in 2007, "The simplest thing I know of is the guillotine and I'm not at all opposed to bringing it back. The person's head is cut off and that's the end of it." That's actually not an unreasonable concept. A guillotine is nearly instant and guaranteed to work the first time. Plus, it conveniently sidesteps the entire Hippocratic Oath quagmire that has plagued medical personnel's involvement with lethal injection—anybody can operate a guillotine, but not everybody can administer an IV. [How Stuff Works - Wiki - CDCR - Al Jazeera - Slate - Top Image: Maxx-Studio, other images: AP Images]