We’ve received a question from a reader which we believe would be of general interest. The writer asks:
How does FEN President Janis Landis know there is no air hunger with nitrogen inhalation onset? Is this an assumption, inference, observation, result of experimentation? Please clarify.
Before responding specifically, I would like to make clear that I am addressing the use of nitrogen, which is an inert gas, as a chemical/physiological process that has been scientifically studied. There has recently been some discussion about the use of inert gas by Oklahoma in executions. We are aware of no studies of such use and this article in no way addresses how that process would work.
The short explanation of why I can be so certain that there is no air hunger is that the physiological impact of inert gas is well understood, and it specifically prevents air hunger. Here is how:
1. Air hunger is driven by an increase in blood carbon dioxide, not by a lack of oxygen.
2. A steady flow of inert gas prevents the buildup of carbon dioxide, just as the flow of oxygen would. An inert gas is defined further below for those that want a more detailed explanation.*
3. Therefore, the physiological response of “air hunger” is not triggered.
How can I be so sure that this explanation is true in the “real world”?
Organizations like the Air Force study the effect of high altitude chambers on pilots. The danger here is that, precisely because there is a depletion of oxygen but no build up of CO2, pilots do not experience the warning of air hunger. Instead they become light-headed, and pass out; if oxygen is not promptly restored, they will not regain consciousness and will die. It is the lack of distress/warning that makes training pilots to respond so critical.
Further, there have been many tragic industrial accidents that involved inert gas. The United States Chemical Safety and Hazard Investigation Board, an independent federal agency, has studied 80 of these incidents and reported its findings:
Breathing an oxygen deficient atmosphere can have serious and immediate effects, including unconsciousness after only one or two breaths. The exposed person has no warning and cannot sense the oxygen level is too low.
Thus both in controlled studies and in actual field situations, the use of inert gases has been scientifically studied, and the impact is completely as our understanding of the chemical process would predict: sudden unconsciousness, followed by a death within 5 to 10 minutes–without the individual regaining consciousness or being aware of a lack of oxygen.
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*Definition: Inert gases in this discussion mean those which are physiologically inert: nitrogen, helium, neon, argon, and a few others. They are generally free of odor and taste. They do not act upon the heart or hemoglobin. Instead, the gas acts as a simple diluent to reduce oxygen concentration being drawn in, and depriving all cells in the body of oxygen. This causes death by asphyxiation – an insufficient supply of oxygen to the body. Asphyxiation (death from lack of oxygen) is without the painful and traumatic feeling of suffocation – the hypercapnic alarm response, which in humans arises mostly from carbon dioxide levels rising.
Dear Ms. Landis,
Your reply rests largely on the hypothesis that increased respiratory carbon dioxide is essential for Inciting air hunger. Perhaps you are correct but I believe current data only shows that Increased respiratory carbon dioxide produces air hunger but not that it is essential. Studies of accidental nitrogen exposures are anecdotal during a catastrophe and suffer from problems with objective observation and report. They are suggestive but not definitive. The experience of carefully measured high flying Pilots Is of hypoxia due to decreased partial pressure rather than Anoxia due to the substitution of a chemically inactive gas. The analogy is also suggestive rather than definitive. I agree that obtaining definitive data would be very difficult.
Is there data concerning the other noble gases such as Argon?
Thank you for your detailed reply. I hope that we may continue this conversation.
Cordially,
Donald Klein
I have been present at the time of departure of several terminally-ill patients who wished to have a peaceful non-traumatic way of shortening their suffering. People who are breathing helium or nitrogen show no evidence of “air hunger” and lose consciousness quickly in a minute or so at most.
I imagine any inert gas such as argon would work equally well as long as there was no “impurity” of oxygen present but I see no reason to test with the more exotic gases since nitrogen works and is readily available and relatively cheap. Gerald Metz, M.D., former Flight Surgeon, 101st Airborne Division.
Fine but where does one of us ordinary folk get nitrogen “readily”?
One of the exercises from my physiology class may address this question. We did not breathe inert gas, but one student in each group received a “rebreather”, a device that collected exhaled air and resupplied it after removing the carbon dioxide (by passing the gas through a lye solution). The test student continued to breathe the same air again and again, gradually using up the oxygen and leaving mostly nitrogen. To avoid harm, the test student signed his name repeatedly. After a few minutes, the signature degenerated to an illegible scrawl. The other group members halted the exercise at that point. The test student expressed surprise at the deterioration of his handwriting and said he had felt perfectly well throughout.
John Julian asked about where nitrogen can be obtained. A direct answer to that question is not discussed on this blog, but anyone can do an internet or library search to learn that nitrogen has many applications in manufacturing, beer brewing, and other commercial activities. From that information, it should be apparent that it is readily available, but anyone interested will have to do their own research.
Detailed article..But nitrogen gas that can be carried by a fragile terminally ill person is 10 litres only..NOT more than that..10 litres of food grade nitrogen gas in a aluminium canister -small size..Is that much quantity is sufficient (that is 10 litres of nitrogen gas only) for self deliverance.? Thanks