Suffocation or Asphyxia is caused by creating a condition of severely deficient supply of oxygen to the body. An example of asphyxia is choking. Asphyxia causes generalized hypoxia, which primarily affects the tissues and organs.
Feeling of suffocation: not enough air or too much CO2?
Everyone knows the unpleasant sensation when holding a breath for a long time. However, this sensation is not caused by lack of oxygen; the main factor is build-up of CO2 in blood. Even if our body constantly needs oxygen, it does not have a mechanism to measure oxygen levels; instead, it relies on CO2 reflex to avoid asphyxia.
Under normal conditions, this reflex works reliably to protect us from high CO2 levels and from lack of oxygen at the same time: our body constantly produces CO2, so if we are unable to breath or are in area with not enough ventilation, CO2 levels rise causing unpleasant sensation. This is the sensation that forces you to grasp for air when diving in a swimming pool.
There is one special situation though: when we are able to freely breathe and exhale CO2, but there is no or not enough oxygen in the mix we inhale. Our body is not built to handle this situation well. When does this situation happen?
- breathing at a high altitude, where air pressure is low. One exhales CO2 freely but the body does not receive enough oxygen. Because CO2 can be exhaled, CO2 reflex is not triggered, there is no suffocation feeling; often, consciousness is lost without any advance warning. Pilots are likely to face this situation in case of aircraft depressurization. Lack of warning before unconsciousness is so dangerous that US Air Force trains crews to recognize signs of approaching hypoxia.
- breathing a gas mix with low oxygen. In the next chapter, we focus on this case.
- Risk of brain damage if rescued
The main hazard of this (and all) asphyxia is the possibility of brain damage if the process is interrupted due to intervention, running out of gas, or tearing or removing the gas mask, plastic bag, or tube tent while unconscious. Using a high concentration can minimize this of the anoxic gas, which causes most rapid loss of consciousness. These gases are not a danger to others in anything but a small, sealed space; however it's important that a gas cylinder not be mislabeled, lest it imperil subsequent users.
An unfortunate practice that results in many accidental deaths.
The plastic bag has been suggested in Final Exit and has been suggested many times on the ASH and ASM newsgroups. The basic principles were supposed to be quite simple, and thus it made the method seem easy to apply and less complex than other methods, which contributed to its popularity.
As suggested on ASH a few times, the required items were:
- The Exit bag (a plastic bag)
- A rubber band
- Some sedatives, like benzodiazepines
In the book Final Exit, it was suggested to ingest benzodiazepines and to then pull the bag with the rubber band on the face and then never wake up. It was claimed that death would occur as a result of the inhalation of CO2, which would ultimately cause suffocation and then death.
The two fundamental factors to make this method work
- 1. The sedatives that you use.
Not all CNS depressants would apply for this purpose. That is, for instance, benzodiazepines work differently than barbiturates. Benzodiazepines work through the limbic system in our brain, which is - among other areas of responsibility - responsible for awakeness and falling asleep. But when benzodiazepines shut down your limbic system, your motoric system is not shut down and continues to be operational. As a result of that, people were observed and reported to have been walking and doing things while they were unconscious due to the benzodiazepines (similar to sleepwalking). That is why this class of drugs is just about perfect for drug cocktails (since you will not be conscious to feel any pain), but not so for any method which requires for our motoric system to be shut down (like this method, since the motoric system has to be shut down so that one does not remove the bag from one's head, due to the feeling of suffocation).
Barbiturates, on the other hand, shut down the neural pathways in the brain because they work through the reticular formation in the brain. This then prevents any motoric activity from occurring.
- 2. The size of the plastic bag.
You would anyhow need at least phenobarbital for the plastic bag method to be reliably lethal, and even then, you would need to have a plastic bag that can clearly provide you with at least one hour of regular and comfortable breathing while your head is in it. This is because it takes a very long time for phenobarbital to put one into a deep coma: during that time, where you are unconscious but not yet comatose, you would re-breathe your own CO2 with a small(er) plastic bag. This would ultimately cause you to reach out and remove the plastic bag from your head, despite your unconscious state. You will then ultimately wake up without knowing what you have done.
Against this method
- The fact that one would need to purchase a plastic bag that is spacious enough to allow for one hour of normal breathing, renders the whole issue complicated for planning and measuring, making the uncertainty factor become considerably serious. One would need to perform a self-test where one tries to breathe in the bag and make sure that the bag is such that it allows for one hour of normal breathing (but not much more than that).
- Even if the size of the bag is the right one, and the sedatives are taken as suggested in this article, the method does not have a particularly good track record. This is even when people tried to carry it out properly.
- There is always the gap between the time where one falls into unconsciousness to the time where one becomes comatose. In that time, anything could happen - unless short-acting barbiturates are used, because the gap is minimal with those drugs (but then there is no need to use any bag at all).
Also, the reasons for failure of the plastic bag method (unless used with an inert gas have been discussed on the ASM newsgroup for a long time. Many posters describe their failed attempts in detail, where they woke up some hours later in a different room or outside, later finding the plastic bag torn somewhere and never remembering what had happened to them).
Could it ever work under any circumstances?
There is a chance that it might work, provided that one makes sure that:
- The bag to be used would have to hold enough air for normal breathing for at least one hour.
- The sedatives to be used must be barbiturates, 5 grams at least.
The most famous myth is that of the initially alleged suicide of the Heaven's Gate religious group, whose members were thought to have taken phenobarbital and then to have put the plastic bags on their heads. However, later, it was discovered that the plastic bags were put on the members' heads by two other members - but only after all the others were already comatose due to the effects of the phenobarbital.
- free breathing, no oxygen
Many gases that are more or less nontoxic can cause asphyxia by replacing oxygen from the breathing mixture. as a result, they are dangerous in enclosed areas, but not otherwise. People start showing signs of asphyxia when the concentration of these gases is around 30 percent; severe symptoms at around 50 percent; death at around 75 percent.
Argon, helium, and nitrogen are your best bets in this category. They are all tasteless, odorless, nonirritating, and under these conditions, chemically and physiologically inert. In fact, nitrogen comprises about 78 percent of the air we breathe. Since these inert gases are not poisonous and your lungs have something to inhale, such asphyxia will be minimally traumatic. That is, they will not cause feelings of suffocation (which are due to carbon dioxide buildup, not the lack of oxygen) or haemorrhages (caused by high blood pressure from blocked jugular vein or struggling to breathe against a closed airway).
Most medical use of inert gases is for animal euthanasia; however there have been human fatalities from them, too. For example, airline face masks were mistakenly hooked up to inert gas cylinders instead of to oxygen at least ten times during the 1980s in the United States. The fact that these people died without attracting attention is consistent with no traumatic death.
- How is inert gas asphyxia different from smothering?
Often, people confuse inert gas asphyxia with smothering (which is not peaceful at all).
Data and differences between the inert gases (pros and cons)
Helium (He) - The density of is 0.14 of the weight of the air we breath, which says it is just about 1/7 of the weight of the air we breath. That's why helium rises.
- Advantages: Quite easy to get [will be discussed later], have been supported by most euthanasia books, and have many case reports to show success.
- Disadvantages: There were cases of failing the method [which we will discuss later]. Though most failures were due to crucial mistakes, yet it needed to take it into account. Another point = 96% of the weight of helium and its inclination to rise, makes it crucial to plan your posture and position well when using it.
Nitrogen (N2) - a colourless, odourless and tasteless gas that makes up 78.09% (by volume) of the air we breathe. The weight of nitrogen is 0.97 of the weight of the air we breathe, which says it is just slightly lighter than air.
- Advantages: since nitrogen is 78% of the air we breathe, breathing this gas should be almost similar to breathing air, in terms of sense. Moreover, its weight being almost similar to the air, dispense of the need to address the possibility of this gas sinking down or rising up when we are unconscious.
- Disadvantages: Poor documented case reports. While this fact by itself does not say it will not be efficient, however, having case reports available may increase our sense of certainty.
Argon (Ar) - its specific weight is 1.39 times of the air's weight.
- Advantages: the gas is way heavier than the air so it sinks to the bottom of the chamber you use, so lying down when performing your attempt is a possibility.
- Disadvantages: poor case reports about it. the same statement about nitrogen is valid here too, that is, it says nothing about the method reliability.
Where can you get inert gases?
Argon is commonly used for inert gas electric welding and helium for balloons. Nitrogen has a variety of uses and may be purchased either as a gas or as a cold (-196 degrees C or -321 degrees F) liquid. All of these are available from industrial gas suppliers. Helium can also be found at party-supply stores. Argon and nitrogen can be found at welding suppliers, or Heating, Ventilating, and Air Conditioning (HVAC) suppliers. None of these gases are dangerous unless they displace oxygen from the breathing mixture.
Advantages of using an inert gas
While breathing inert gas gives no feeling of suffocation or choking. This is because the breathing permits the lungs to continue exhaling carbon dioxide and the brain never receives any warning signal of suffocation.
Death by inhalation of Inert gas is not detectable through any known toxicity test, beyond the signs of suffocation. Only a witness or materials left in the scene can confirm the inhalation as a cause of death. The gas may tend to rapidly dissipates into the surrounding air and since it is not metabolized or absorbed (as it is inert), it will not remain in the body tissues or blood cells.