Is euthanasia painless? The founder of the British pro-euthanasia movement (and sometime eugenicist) Dr Killick Millard declared in 1931 that his aim was ‘to substitute for the slow and painful death a quick and painless one’. His sentiment is echoed today by the pro-euthanasia group My Death, My Decision, which says that it wants the ‘option of a peaceful, painless, and dignified death’. The British Medical Association appears to agree and this week dropped its opposition to the Assisted Dying Bill, currently making its way through parliament.

As a doctor and expert witness against the use of lethal injection for execution in America, however, I am quite certain that assisted suicide is not painless or peaceful or dignified. In fact, in the majority of cases, it is a very painful death.

The death penalty is not the same as assisted dying, of course. Executions are meant to be punishment; euthanasia is about relief from suffering. Yet for both euthanasia and executions, paralytic drugs are used. These drugs, given in high enough doses, mean that a patient cannot move a muscle, cannot express any outward or visible sign of pain. But that doesn’t mean that he or she is free from suffering.

In 2014, I watched the lethal injection of Marcus Wellons in a Georgia prison. The 59-year-old had been sentenced to death for the rape and murder of his 15-year-old neighbor India Roberts in 1989. ‘I’m going home to be with Jesus’ were his final words as the drugs entered his body.

I noticed that Wellons’s fingers were taped to the stretcher, which made little sense, given his body had already been restrained by heavy straps. I kept asking myself why. I read into the subject and came across a report of the lethal injection execution of another death row inmate, Dennis McGuire, five months earlier. During that 24-minute process at the Ohio jail, McGuire clenched his fists. Perhaps it was a final, futile show of defiance. Perhaps it was an outward display of pain. With his fingers secured, Wellons could not have made any such gesture.

In 2017, I obtained a series of autopsies of inmates executed by lethal injection, which confirmed my worst fears. Wellons’s autopsy revealed that his lungs were profoundly congested with fluid, meaning they were around twice the normal weight of healthy lungs. He had suffered what is known as pulmonary edema, which could only have occurred as he lay dying. Wellons had drowned in his secretions. Yet even my medical eye detected no sign of distress at his execution.

In America, there is no stated means of death for victims of lethal injection. Federal litigation dictates that executions must not be ‘cruel’ but they are permitted to be ‘painful’. Far from the ‘instantaneous death’ sought by the Supreme Court justices, drowning in this manner is both prolonged and painful.

Wellons was executed with a chemical called pentobarbital, which caused his pulmonary edema. In Oregon, four in five assisted suicides have employed pentobarbital or its close relatives. (The Assisted Dying Bill is based on the Oregon system.) If a post-mortem examination were to be performed on a body after assisted suicide, it’s very likely that similar pulmonary edema would be found.

Increasingly, drug shortages have forced states in America wishing to execute inmates to improvise. Some use barbiturates like pentobarbital in isolation, others mask its effects with other drugs. In either case, it is the lethal barbiturates that trigger death. What is to say the same thing won’t eventually end up happening in Britain with assisted dying?

The proposals before Britain’s House of Lords would see sick patients prescribed a lethal dose of perhaps 100 barbiturate pills. Laws in Oregon, like those proposed in the UK, require patients to take the drugs themselves, which rules out any form of general anesthetic. Often patients are handed anti-sickness and anti-seizure tablets but nothing more in preparation, meaning they’re very much awake as the assisted suicide process begins and they start ingesting fatal quantities of barbiturates. Without a general anesthetic, many will be in great discomfort, even if outwardly they don’t appear to be suffering.

Indeed, there are countless examples of people who have discovered just how messy, painful and distressing it can be as they watched their loved ones go through the process. Take Linda Van Zandt, who helped her aunt, suffering from amyotrophic lateral sclerosis, die in California. She later described how she had to feed 100 crushed pills in a drink to her aunt ‘who could barely swallow water’, but ‘had to drink all of it in less than five minutes to “ensure success”’. She concludes: ‘The day was fraught and frightening… We had been forced to assist in the most bizarre fashion, jumping through seemingly random legal hoops and meeting arbitrary deadlines while my aunt suffered, and finally emptying capsules, making an elixir so vile I cried when I knew she had to drink it. This was death with dignity?’

I have met and explained my findings to many inmates on death row. Based on this pulmonary edema information, three inmates on Tennessee’s death row considered their options. Having heard the consequences of the process shared between assisted suicide and lethal injection, all three chose to die instead by the electric chair.

Advocates of assisted dying owe a duty to the public to be truthful about the details of killing and dying. People who want to die deserve to know that they may end up drowning, not just falling asleep.

This article was originally published in The Spectator’s UK magazine. Subscribe to the World edition here.