Nitrogen hypoxia, the planned method of execution in Alabama, can cause rapid loss of consciousness by depriving the brain of oxygen.
Authorities in Alabama were scheduled to execute death row inmate Alan Miller on Thursday, but on Monday a federal judge blocked the execution.
The reason was that Miller chose to be executed by nitrogen hypoxia, a currently untested method of execution that the state authorized in 2018.
His authorization means inmates can choose to be executed via this method if they wish, which Miller claims he did by filling out a form and leaving it for a prison officer to collect, according to the agency. AP press release.
Prison officials said they had no record of this. This week, the state was not quite ready to carry out an execution using this method.
Miller said during his testimony that he chose the nitrogen hypoxia method because it reminded him of the nitrous oxide used by dentists and that it seemed better than a lethal injection because it fear of needles.
U.S. District Judge R. Austin Huffaker, Jr., issued an injunction to restrain the execution from continuing by any method other than nitrogen hypoxia. He noted that Alabama may soon be able to apply the method, AP reported.
Miller was sentenced to death after being convicted of an Aug. 5, 1999, workplace shooting that killed three people in Shelby County, Alabama. Miller was mentally ill, according to a psychiatrist hired by the defense, CBS reported. He has been on death row since 2000, according to the Shelby County Reporter.
Professor Rob Chilcott, head of toxicology at the University of Hertfordshire in the UK, said Newsweek about how nitrogen can affect the body and why the untested method of execution could kill.
“Hypoxia is the medical term that describes an insufficient amount of oxygen in the body,” he said. “Normally, the air we breathe contains about 21% oxygen. Adding excess nitrogen to the air will dilute the oxygen concentration and, depending on the “dose” of nitrogen, will cause varying degrees of hypoxia.
“If enough nitrogen is added to lower the oxygen concentration to less than about 5%, the person breathing the air will quickly become unconscious. In the absence of any intervention, death will occur soon after. »
Nitrogen can also be very dangerous outside the context of controlled execution. Chilcott said there have been around 60 deaths in the UK from nitrogen exposure in the past five years.
“Normally the human body monitors carbon dioxide levels in the blood, not oxygen,” he said. “For example, when we exercise, we produce excess carbon dioxide. This stimulates the respiratory center of the brain, which leads to an increase in respiratory rate – we breathe harder and faster to remove excess carbon dioxide from our bodies.
“However, artificially adding excess nitrogen to the air will reduce blood oxygen levels but not increase the amount of carbon dioxide in the blood. Thus, inhaling a nitrogen-rich atmosphere will not produce a physiological signal to alert the body to a lack of oxygen. This is why inert gases such as nitrogen and helium are very dangerous. »