After the condemned is fastened on the execution table, two
intravenous cannulae ("drips") are inserted, one in each arm. Only one is used for the execution; the other is reserved as a backup in case the primary line fails.
The arm of the subject is swabbed with
alcohol before the cannula is inserted.
[8] The needles and equipment used are also sterilized. One reason for this is that cannulae are standard medical products that are sterilized during manufacture. 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 executed eventually on
March 14,
1984). Finally, it would also be a hazard for those handling unsterile equipment.
The
intravenous injection is usually a sequence of compounds, designed to induce rapid
unconsciousness followed by death through
paralysis of respiratory muscles and/or by inducing
cardiac arrest through
depolarization of cardiac muscle cells. The execution of the condemned in most states involves three separate injections:
- Sodium thiopental: to render the offender unconscious.
- Pancuronium/Tubocurarine: to stop all muscle movement except the heart. This causes muscle paralysis, collapse of the diaphragm, and would eventually cause death by asphyxiation.
- Potassium chloride: to stop the heart from beating, and thus cause death: see cardiac arrest.
The drugs are not mixed externally as that can cause them to
precipitate.
The intravenous tubing leads to a room next to the execution chamber, usually separated from the subject by a curtain or wall. Typically a technician trained in
venipuncture inserts the cannulae, while a second technician, who is usually a member of the prison staff, orders, prepares, and loads the drugs into an infusion pump. After the curtain is opened to allow the witnesses to see inside the chamber, the condemned person will then be permitted to make a final statement. Following this, the warden will signal for the execution to commence, and the executioner(s) (either prison staff or private citizens depending on the jurisdiction
) will then activate the infusion pump which mechanically delivers the three drugs in sequence. During the execution, the subject's cardiac rhythm is monitored. Death is pronounced after cardiac activity stops. Death usually occurs within seven minutes, although the whole procedure can take up to 2 hours, as was the case with the execution of
Christopher Newton on
May 24,
2007. According to state law, if participation in the execution is prohibited for physicians, the death ruling is made by the state's Medical Examiner's Office. After confirmation that death has occurred, a coroner signs the executed individual’s death certificate.