User:Artour2006/Normal breathing pattern
Parameters and description of the normal breathing pattern
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The physiological norm for minute ventilation at rest is 6 litres per minute for a 70 kg man [1] [2] [3] [4].
These textbooks also provide the following parameters of the normal breathing pattern:
- normal tidal volume (air volume breathed in during a single breath): 500 ml;
- normal breathing frequency: 12 breaths per minute;
- normal inspiration: about 2 seconds;
- normal exhalation is 2-3 seconds.
Other parameters of the normal breathing pattern
[edit]“If a person breath-holds after a normal exhalation, it takes about 40 seconds before breathing commences”[3]. This indicates normal oxygenation of tissues.
The current medical norm for CO2 content in the alveoli of the lungs and the arterial blood is 40 mm Hg CO2. This number was established about a century ago by the famous British physiologists Charles G. Douglas and John S. Haldane from Oxford University. Their results were published in 1909 in the article The regulation of normal breathing by the Journal of Physiology (Douglas & Haldane, 1909)[5].
Normal breathing is strictly nasal and “the diaphragm is responsible for approximately 75% of inspiration during quiet breathing”[4].
Normal breathing is regular, invisible (no chest or belly movements), and inaudible (no panting, no wheezing, no sighing, no yawning, no sneezing, no coughing, no deep inhalations or exhalations).
If a healthy person is asked about their breathing sensations, they will testify that they do not feel their breathing (because it is very small).
Sick people usually feel movements of air, chest movements, and other effects related to their big and noisy breathing. Their deep breathing reduces body oxygenation and creates tissue hypoxia due to hypocapnic constriction of blood vessels and the suppressed Bohr effect.
In order to define one’s breathing pattern, measure your body oxygenation or breath holding time after your usual exhalation, but only until the first stress or discomfort.
The person with normal breathing is going to have about 40 s breath holding time (or body oxygenation index). In case of chronic over-breathing, breath holding time becomes shorter indicating reduced body oxygen stores.
Sick people have deep and fast breathing 24/7 and reduced body oxygenation (usually about 10-20 s of oxygen in tissues). In the severely sick and critically ill patients, body oxygenation is below 10 s. If sick people retrain the way they breathe, their body oxygenation is restored and symptoms of many chronic conditions disappear.
Alternative norms for the normal breathing pattern
[edit]Soviet physiologist Professor_Konstantin_Buteyko, PhD, MD, the creator of the Buteyko method for the treatment of asthma and other breathing disorders,based on his studies of thousands of healthy and sick people, suggested different norms for breathing[6]:
- normal minute ventilation: 4 l/min
- normal tidal volume (air volume breathed in during a single breath): 500 ml;
- normal breathing frequency: 8 breaths per minute;
- normal inspiration: about 2 seconds;
- normal exhalation: 2-3 seconds.
- normal automatic pause (or period of total relaxation): 3 seconds.
- normal breath holding time (after usual exhalation and without stress at the end of the test): 60 seconds;
- normal CO2 concentrations in the alveoli and arterial blood – 6.5% or about 46 mm Hg.
References
[edit]- ^ Ganong WF, Review of medical physiology, 15-th ed., 1995, Prentice Hall Int., London.
- ^ Guyton AC, Physiology of the human body, 6-th ed., 1984, Suanders College Publ., Philadelphia.
- ^ a b McArdle W.D., Katch F.I., Katch V.L., Essentials of exercise physiology (2-nd edition); Lippincott, Williams and Wilkins, London 2000.
- ^ a b Straub NC, Section V, The Respiratory System, in Physiology, eds. RM Berne & MN Levy, 4-th edition, Mosby, St. Louis, 1998.
- ^ Douglas CG & Haldane JS, The regulation of normal breathing, Journal of Physiology 1909; 38: p. 420–440.
- ^ Buteyko KP, Method of voluntary elimination of deep breathing, Buteyko method [in Russian], in Buteyko method. Its application in medical practice, ed. by K.P. Buteyko, 2-nd ed., 1991, Titul, Odessa, p.148-165.
Artour2006 (talk) 19:07, 15 June 2009 (UTC)