Can voluntarily hyperventilating by raising one's resting respiratory rate to 30 breaths/min cause cerebral hypoxia, and therefore brain cell death (brain damage)?
1 Answer
Essentially, yes you could hyperventilate to cause a subtle cerebral hypoxia (as also happens briefly during a faint), but once unconscious you would return to automatic breathing and the effects of the hyperventilation would reverse.
There is some interesting information in this article. Although it relates to hyperventilation as relevant to anaesthetics (e.g. induced hyperventilation is often used in neurosurgical procedures to reduce intracranial pressure) it provides a good overview as well.
Hyperventilation exerts... many effects upon the body relevant to anesthesia and the functioning of the brain.
Hyperventilation (increasing the rate of breathing) causes increased ventilation of the lungs and increased excretion of carbon dioxide (CO2). This leads to reduced CO2 pressure in the blood, and a change in acid-base balance (towards more alkalinity) and biochemisty. The end result can have significant physiological changes.
The effects of hyperventilation
Mental effects of hyperventilation are very mixed. People with hyperventilation commonly describe symptoms such as disturbed mentation, impaired concentration, poor memory, and hallucinations. Feelings of depersonalization are also common, where hyperventilating persons describe sensations of unreality, or feeling everything is confused and dream-like. Visual experiences such as blurred vision, tunnel vision, flashing lights, and seeing double also occur (Evans 2005, Lum 1987, Perkin 1986). Extreme hyperventilation causes loss of consciousness in 31% of people with hyperventilation disorder (Perkin 1986), is occasionally observed during experimental hyperventilation (Kety 1946), and in some pregnant women hyperventilating due to labor pains (Burden 1994). But this is not all. Hyperventilation can sometimes even cause brain death.
The article includes some detail of the biochemistry of these changes, if you are interested. Essentially cerebral blood flow reduces, and this can cause unconsiousness.
So while you could hyperventilate yourself into unconsciousness, the voluntary hyperventilation will of course then stop, with a return to normal tidal breathing which will eventually reverse the changes. In an otherwise healthy person, this is unlikely to do damage.
The situations in the article where hyperventilation causes cerebral hypoxia or damage were in anaesthetised people being mechanically hyperventilated, which is a very different situation.
