Then, at the warden's signal, a curtain is raised exposing the inmate to the witnesses in an adjoining room. Then, the inmate is injected with sodium thiopental - an anesthetic, which puts the inmate to sleep. Next flows pavulon or pancuronium bromide, which paralyzes the entire muscle system and stops the inmate's breathing. Finally, the flow of potassium chloride stops the heart. Death results from anesthetic overdose and respiratory and cardiac arrest while the condemned person is unconscious.
Medical ethics preclude doctors from participating in executions.
However, a doctor will certify the inmate is dead. This lack of medical participation can be problematic because often injections are performed by inexperienced technicians or orderlies. If a member of the execution team injects the drugs into a muscle instead of a vein, or if the needle becomes clogged, extreme pain can result. Many prisoners have damaged veins resulting from intravenous drug use and it is sometimes difficult to find a usable vein, resulting in long delays while the inmate remains strapped to the gurney.