Alabama is set to perform the second-ever nitrogen gas execution in the United States on Thursday.
Alan Eugene Miller, 59, was sentenced to death for the 1999 murders of his then-coworkers Lee Holdbrooks and Christoper Scott Yancy, and his former supervisor Terry Lee Jarvis.
Miller was to be executed in September 2022 via lethal injection, but it was called off after officials had trouble inserting an intravenous line to administer the fatal drugs and were concerned they would not be able to do so before the death warrant expired.
Same thing for nitrogen, or any gas besides CO2. The human body has no way to detect oxygen. It can only detect CO2.
Not relevant to the argument at hand, but the body does have low O2 detection. I’ve held my breath with a pulse oximeter on before, and while high CO2 makes you panic, when you get to about 87% your body has a response I would describe as “breathe, mother fucker” which is hard to ignore. COPD patients often regulate using this hypoxic drive.
If you hold your breath the CO2 accumulates in your blood, making it acidic and triggering the “breathe, mother fucker” reflex.
You need to exhale the CO2 without inhaling O2 for the body to not realize it.