Procedure in U.S. executions
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Executions by the federal government are carried out at the Terre Haute Federal Correctional Complex. The picture is of a gurney on which prisoners rest during an execution by lethal injection.The condemned criminal offender is strapped onto a gurney; two intravenous cannulae ("IVs") are inserted, one in each arm. Only one is necessary to carry out the execution; the other is reserved as a backup in the event the primary line fails. A line leading from the IV Line in an adjacent room is attached and secured to the prisoner's IV, and secured so the line does not snap during the injections.
The arm of the offender is swabbed with alcohol before the cannula is inserted.[9] The needles and equipment used are also sterilized. There have been questions about why these precautions against infection are performed despite the purpose of the injection being death. There are several explanations: cannulae are sterilized during manufacture, so using sterile ones is routine medical procedure. Secondly, there is a chance that the prisoner could receive a stay of execution after the cannulae have been inserted, as happened in the case of James Autry in October 1983 (he was eventually executed on March 14, 1984). Finally, it would be a hazard to prison personnel to use unsterilized equipment.
Following connection of the lines, saline drips are started in both arms. This too is standard medical procedure: it must be ascertained that the connections are clear, ensuring that the chemicals do not mix in the IV lines and occlude the needle, preventing the drugs from reaching the inmate. A heart monitor is attached so that prison officials can monitor when death has occurred.
The intravenous injection is usually a sequence of drugs given in a set sequence, designed to first induce unconsciousness followed by death through paralysis of respiratory muscles and/or by cardiac arrest through depolarization of cardiac muscle cells. The execution of the condemned in most states involves three separate injections (in sequential order):
Sodium thiopental: ultra-short action barbiturate, an anaesthetic agent capable of rendering the prisoner unconscious in a few seconds.
Pancuronium: non-depolarizing muscle relaxant, causes complete, fast and sustained paralysis of the skeletal striated muscles, including the diaphragm and the rest of the respiratory muscles; this would eventually cause death by asphyxiation.
Potassium chloride: stops the heart, and thus causes death by cardiac arrest.
The drugs are not mixed externally as that can cause them to precipitate. Also, a sequential injection is key to achieve the desired effects in the appropriate order: administration of the barbiturate is essential to minimize physical distress during the process; the infusion of the muscle relaxant induces complete paralysis but not unconsciousness, and the injection of a highly-concentrated solution of potassium chloride can cause severe pain in the site of the IV line as well as along the punctured arm.
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