No one has studied respiratory rate and depth in humans, despite the lip service regarding the importance of vital signs. Even the measurement of tidal volume is relatively new; it is only in the 1980’s that spirometry was utilized to detect asthma and chronic obstructive pulmonary disease. A brief history of the spirometer, 150 years in the making.
Breathing is a complex motor act orchestrated by the brain and the body; the lungs are only part of the story of breathing.
In the first aid that Paula and I took, we rediscovered what researchers in the 1900’s knew, that the range of respiratory rate was very wide in groups of people [our group was 30 or so adult working people. In out group baseline respiratory rates were as low as 3 breaths per minute and as high as 30 breaths per minute at rest. Tidal volumes were unknown.
We eventually got a doctor to give Paula a spirometry test and we found out that her lungs were normal and that her tidal volume is .5L per breath, which is great.
Textbooks assume that most humans move 6-8 Litres of air in and out of their bodies per minute. Textbooks assume an average baseline breathing rate of 12 to 18 breaths per minute at rest.
Paula, with her baseline respiratory rate of 3 breaths per minute moves 1.5 Litres of air per minute, far less than the textbooks state is necessary to be alive [or so they suggest],. Paula is very healthy and active and smart and alert. Her breathing rate rises during locomotor activity, but sluggishly. Her breathing rate stays at baseline and does not rise in response to illness and limitations in flow rate due to a blocked nose or a cold. This must present difficulties in maintaining normal pH of the blood, yet this remains unknown.
So the textbooks are wrong. And the complex motor act of breathing and its role in control of CO2 of the blood is not what we assumed it was.
I can understand why Paula might be more prone to attacks of hypercapnia and mental confusion than other people, but except for one yearlong attack during a period of hormonal change [menopause] Paula has been completely fine, completely normal.
Breathing, mind, loss of mind, it is all connected somehow.
First, though, we must figure out how people at both ends of the range of respiratory rates, too slow and too fast, manage their PCO2 and pH levels.
No one has ever thought to study this before, well almost no one;* Dr Emile Kraepelin thought that abnormal respiratory rate was significant because he found thousands of people with “slow ” breathing [which doctors often conflate with respiratory failure] suffering from attacks of unpleasant altered mental confusion, he named depressive insanity- which is what Paula experienced during her year long illness. * ManicDepressive Insanity, Dr E. Kraepelin, 1926
There is a lot science does not know about breathing, breathing rate and its effect on mind.