A failure of a basic autonomic nervous system reflex affecting exchange of air per minute at rest when awake – would seem rather incompatible with life itself. Yet it seems that Nature has an APP for that. We found this out accidentally in a first aid class and found it very exciting. Paula didn’t know. No one knew. It was a hidden physical sign, until it was unmasked through measurement.
Paula exchanges only 1.5 litres of air per minute due to her breathing rate of 3 breaths per minute. And she seems not to be able to increase the amount of air she exchanges in times of illness. Yet for the most part she has been able to fight off common bouts of illness just like any one else. But not always…..she is at increased risk of hypercapnia due to respiratory pump failure.
This is a new area of research, despite the clues available to us, thanks to early 20th century pioneers such as JS Haldane and E. Kraepelin. https://archive.org/details/manicdepressivei00kraeuoft, 1921Topics Psychiatry — Early works to 1900, Manic-depressive illness, ParanoiaPublisher Edinburgh : LivingstoneCollection gerstein; toronto; medicalheritagelibrary; university_of_torontoDigitizing sponsor MSNContributor Gerstein – University of TorontoLanguage English
Both of these researchers found disturbing evidence suggesting that doctors do not understand injuries affecting the autonomic nervous system when it affects the ability to ventilate, this having little to do with the lungs at all. I suppose that this is the area of general medicine and of neurology. But it is not part of medical tradition to examine ventilatory rate and the vital signs in order to check for possible plasticity and for possible limitations during illness not faced by others.
Paula’s is alive and well. This suggests that our assumption of 6-8 litres of air exchanged per minute in humans is incorrect for a minority of people. . And, we would not even know this if not for Paula, or JS Haldane’s experiments and or E. Kraepelin’s work. Most biologists and biochemists and physiologists and doctors do not know of this work. We take the autonomic nervous system for granted, especially minute ventilation. [respiratory rate times tidal volume.] We take breathing for granted because the autonomic nervous system works “under the radar”. We are not aware of it, as long as we feel fine and are in good condition. Often we are not aware of when we are ill, especially when our brains are not working properly and this affects our minds. Failure of the A.N.S reflexes in the complex motor system of breathing will cause disabling symptoms. Neither the patient nor the doctor will know why unless the doctor understands that the measurement of the respiratory rate is the key.
The amount of air a person exchanges normally at rest when awake is something doctors do not measure in health or in illness and especially in neurological and neuropsychiatric illness.
Paula and I have worked as volunteers in various hospitals and have measured breathing rates in a number of neurological and neuropsychiatric patients [ plus we took their pulse oximetry ] as a project. Many had unusual respiratory rates and normal 02. [of course most were medicated so this skews things]. Like Haldane, we found a wide range of respiratory rates, from as low as 3 breaths per minute to as high as 30 breaths per minute in patients who were stable in their disease process. We think that this reduces the flexibility of the respiratory system to adapt to changes in blood gases due to illness. We think that this knowledge would help us to help the autonomic nervous system when it needed extra mechanical help to manage blood gas challenges.
Paula’s case, Haldane experiments and Kraepelin studies show us that there is a lot that we need to learn in order to understand the function of the nervous system, the body, the brain and the mind. And this work involves measurement of the most basic reflexes underlying life and biology in illness and in health. What could be more exciting. This is a problem that we were not even aware of and one that we can easily study.
“Respiratory reflexes encompass a significant repertoire of responses to a variety of sensory receptors regulating the depth and frequency of individual breaths and participating in the protection of airways from potentially damaging inhaled substances. Specifically, receptors in the airways and lungs sense the relative inflation or deflation of the lungs as well as the presence of inhaled irritants, and elicit appropriate responses via brainstem respiratory circuits to maintain the integrity and efficient function of the lungs and airways”. Mccrimmon D.R., Alheid G.F. (2009) Respiratory Reflexes. In: Binder M.D., Hirokawa N., Windhorst U. (eds) Encyclopedia of Neuroscience. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-540-29678-2_5081
What if this system is disrupted at birth? This happened to Paula, who was born anoxic, was resuscitated [hyper-oxic exposure], then transfused and turned out fine from then on. Good work Doctors! And, it seems, that Paula was the lucky inheritor of respiratory plasticity altering her autonomic nervous system reflexes for ventilation rate. [her depth of breathing is completely normal at .5 litres per minute]. She does not need to breath as much as the rest of us and neither she nor we were aware of this until that first aid class. Measuring her respiratory rate [in health] unmasked her superpower.
And indeed, exchanging only 1.5 litres of air per minute is quite a superpower. Who knows, perhaps this is why she is so fit, looks young [at 65] and is very smart? And her 02 [pulse oximitry ] is normal, as is her HCO3. This is the opposite of what we would expect so….. it must be important.
Who doesn’t like a biological mystery to solve? A lot of folks, it seems. Many doctors and scientists shy away from Paula. It seems too frightening to them, as if she is a mutant or something. And she is perfectly fine…..
Scientists know that breathing air begins at birth and eating food through the digestive system begins at birth, leaving lots of plasticity to occur in order to adapt to the conditions at birth. Paula had to adapt to anoxia, hyperopia, resuscitation [including intubation] and foreign blood products and the complications of 1955 medical technology. The evidence of adaptation and plasticity is clear when measuring and analyzing the pattern of her vital signs, in particular breathing rate and depth [which everyone likes to ignore.] Without measurement of her minute ventilation and other vital signs, she looks like an average person. But she is an exceptional person. And her risk for hypercapnia [or hypocapnia -who even knows] is much greater because of her inability to raise her breathing rate in illness.
Illness is a stimulant and usually activates reflex systems to correct acid base changes and fight inflammation and infection. Since she cannot raise her breathing rate, the brain tries to conserve energy till things improve. She speaks and moves very little and cannot access her entire brain, affecting executive functions. She does not eat or drink, she loses weight [involuntarily] and becomes mildly hypothermic. Thyroid function declines. She retains fluids. All this helps a little to reduce her metabolism and production of CO2 by the cells. When she finally does need to raise her breathing rate, the only way she seems to be able to do this is to make the motor system function faster than normal because ordinary rate of speech and movement does not raise her breathing rates enough. It takes involvement of the whole body to keep blood gases in check as much as possible. People like Paula need the voluntary skeletal muscle system to pitch in in order to help the respiratory pump do its job when the autonomic nervous system reflexes fail. All of this is co-ordinated by the autonomic nervous system which co-opts any system it needs to help the patient stay alive.
Every organ system needs the correct ratio of air to function. This is especially true of the executive functions of the brain, I think. It is true that today we have fancier tests to evaluate arterial blood gases and that homeostasis and function is highly dependent on tight control of these. But in reality, ABG [arterial blood gas tests] are never used to understand the autonomic nervous system, its unexpected problems and how it maintains acceptable blood gas in the face of [hidden] autonomic reflex failure in the adult population. This is because the autonomic nervous system can only talk to us through measurement of the vital signs. It works invisibly, even when it is unable to work adequately. JS Haldane found too slow seemingly inadequate respiratory rates in the heathy adult population and E Kraepelin found the same in thousands of the insane.
And Paula is a living example of what they found and no one knows how she remains alive, much less why she is doing so well.
We have a lot of scientific sleuthing and scientific thinking and rethinking to do, don’t you think?