Anything But Humane
The search for a "humane" way of killing people should be seen for what it is -- a search to make executions more palatable to those carrying out and witnessing the killing. This includes the governments that wish to appear humane and the public in whose name the killing is carried out.
Lethal injection can cause excruciating pain. Since the first lethal injection on December 7, 1982, over 1,000 prisoners in the USA have been executed by this method and it has all but replaced other methods of execution.
In the USA, a number of lethal injection executions have been botched. Some executions have lasted between 20 minutes to over an hour and prisoners have been seen gasping for air, grimacing and convulsing during executions. Autopsies have shown severe, foot long chemical burns to the skin and needles have been found in soft tissue.
Lethal injection was designed to prevent many of the disturbing images associated with other forms of execution. However, lethal injection increases the risk that medical personnel will be involved in killing for the state, in breach of long-standing principles of medical ethics.
Virtually all codes of professional ethics which consider the death penalty oppose health professional participation. Despite this, health professionals are required by law in many death penalty states to assist executions and in some cases have carried out the killings.