Remember all the young and stupid things you did when you were young and stupid? Jumping off the garage with a pillowcase parachute? Swinging off a tree limb into the creek or pond without first testing the depth of the water? Building a ramp to jump over on your bicycle? Taking a ride while clinging to a car front fender? We all did these things yet somehow survived. Unfortunately young Brandon Stine didn’t.
There seems to be a game going around among children Brandon’s age, which was 11 at the time of his death. It goes by many names: the Choking Game, the Fainting Game, the Pass Out Game, Tap Out, Hangman, Elevator, and a few others. The goal is to lose consciousness. I remember in grammar school a similar game came around. The person would take 20 deep breaths and blow on their thumb and immediately become dizzy and lose consciousness. I never played this game but I saw it on several occasions. Somehow losing consciousness wasn’t very appealing to me. And of course now that I know the physiology behind it, it is not only unappealing it is frightening.
The current games are played two ways. The first is easy to understand and the second requires a little more complex physiology.
One form is simply to choke the victim until he loses consciousness. This is basically the choke hold police sometimes employ to control combative suspects. The purpose is to block blood flow to the brain by compressing the carotid arteries. This results in low oxygen levels in the brain, which in turn leads to loss of consciousness. It can also lead to death.
The second form results from self-induced hypocapnia. Hypocapnia is simply a big word for low carbon dioxide (CO2) levels in the blood.
The human body guards a handful of things very jealously. Some of these are the oxygen, CO2, and pH of the blood. The pH is a measure of the balance between acid and base (alkalinity) in the blood.
When oxygen levels are low, the brain sends out signals that increase the rate and depth of breathing as well as the heart rate and blood pressure. This brings more oxygen into the lungs and increases its transportation by way of the cardiovascular system to the body. When the level of oxygen in the blood is very high the exact opposite happens in that breathing will slow since there is no physiologic need to move more air.
Carbon dioxide works the same way, only in reverse. If the carbon dioxide levels are high, breathing will increase to “blow off” this extra CO2, which is an acid. Since CO2 is removed from the body through the lungs any increase in breathing rate and depth will remove more CO2 from the body and the acid-base balance (the pH) will be restored. If the CO2 is very low, this drive to breathe is suppressed so that more CO2 will accumulate within the blood and again restore the pH balance.
High CO2 levels elevate the amount of acid in the blood and this is reflected in a falling pH level. The lower the pH the more acidic the body is. A low pH adds to the drive to breathe more rapidly so that the CO2 level will drop and the excess acid is removed in this way. When the CO2 level drops, the pH rises and the drive to breathe is suppressed.
This is a thumbnail and does not take into consideration the many other derangements within the body that can alter the pH level.
In summary, a low oxygen level, a high CO2 level, and a low pH (excess acid in the system) tend to increase breathing so that more oxygen is supplied and more CO2 is removed from the body. When the oxygen level is high, the CO2 level is low, and the pH is elevated (excess alkalinity in the system) the driving force to breathe is suppressed.
When someone purposely hyperventilates by breathing rapidly and deeply for a minute or so they are increasing their oxygen and pH levels while lowering their CO2 levels. This in turn suppresses the need to breathe. This can lead to a period of slow or absent respiration, which tends to continue slightly longer than is needed. This overshoot is part of virtually all biological feedback systems. This can result in a rapid drop in blood oxygen levels to the point that the victim loses consciousness.
This drop in blood oxygen level is more dramatic and more rapid than is the restoration of normal CO2 levels that would accompany a cessation of breathing. This means that by the time the CO2 levels reach a point where they again drive respirations, the oxygen level has fallen very far. This is what leads to loss of consciousness and death. Or perhaps survival with permanent brain damage.
An identical situation arises when someone attempts an underwater swim across a pool. Or a free diver attempts to go to very great depths on a single breath. In each of these situations the person hyperventilates before taking the plunge and in so doing creates a situation where they could lose consciousness and drown during the swim or the descent.
If you, or anyone you know, has children who are playing this game, it’s time to sit down and have a chat. This is basically Russian Roulette where the bullets are the oxygen and carbon dioxide levels in the blood.