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The Buteyko Method, or Buteyko Breathing Technique is a holistic health philosophy, primarily for the treatment of asthma, that includes a set of breathing exercises developed by the late Russian doctor, Konstantin Pavlovich Buteyko (Russian: Бутейко). The method is taught as a complementary therapy and several small clinical trials have shown that it can safely reduce asthma symptoms and the need for reliever medication in some people, as well as increasing quality of life scores. However, improvement takes time and commitment, requiring daily exercises over a period of weeks or months and tuition can be expensive.
At the core of the Buteyko method is a series of breathing exercises that focus on nasal-breathing, breath-holding and relaxation. At present it is used to treat asthma, sleep apnea, snoring, anxiety attacks and panic attacks. These conditions are associated with disrupted or irregular breathing patterns and the Buteyko exercises aim to 'retrain' breathing to restore a natural pattern, akin to certain forms of Yoga.
Despite evidence that Buteyko can be an effective treatment for asthma, it is still subject to skepticism from the medical community. This is mainly due to the lack of a controlled large-scale trial of the method and no explanation for why the Buteyko exercises work. Professor Buteyko's own proposed physiological mechanism, the "CO2 theory", is popular amongst teachers of the technique, but has more opposing than supporting scientific evidence. The general view of the medical community is that the Buteyko method is at least unlikely to do any harm.
Professor Buteyko was born on 27th January 1923 in Ivanitsa, near Kiev. After a brief stint in the Russian armed forces he decided to follow a career in medicine and enrolled as a medical student in Moscow in 1946. During his medical studies he was given a project of making observations on patients’ breathing rates in relation to the severity and prognosis of their illness. He soon came to the conclusion that there was a correlation between these two factors, such that as a patient’s condition became more severe so their breathing rate increased.
After qualifying as a doctor he continued his studies on the relationship between breathing and ill-health. He reasoned that if there really was a connection between hyperventilation and illness it should be possible to reverse this by deliberate breath control. Having already made a study of several texts on yoga he was aware of exercises in breath restriction and so began to experiment both on himself and with his patients.
By the early 1980s the Russian authorities were sufficiently impressed to allow him to conduct a formal trial, or ‘approbation’, with asthmatic children in a Moscow hospital. Although very different in design from the standard controlled trial now predominant in the west, the results were sufficiently impressive to persuade the State Medical System to approve the method for widespread use. To date, it is estimated that over a hundred thousand asthmatics in Russia have been helped by Dr Buteyko’s work, and probably as many in the rest of the world as well.
In the late 1980s an Australian business man was admitted to hospital in Russia for treatment of an attack of angina. He was introduced to the Buteyko method (known in Russia as ‘Voluntary Elimination of Deep Breathing’ or VEDB) and found it extremely helpful. The Australian sponsored two Russian practitioners to teach the techniques in Australia. Within a short time, one of these people, Alexander Stalmatski was also training new teachers. The first blinded, controlled trial of Buteyko was carried out in 1994. Since then the Buteyko method has spread across the world and the number of people teaching this method grows every year. Professional bodies have been formed to promote safe, accurate and standardised teaching of the method.
Professor Buteyko died on May 2nd, 2003, aged 80.
It is not known exactly why Buteyko works, but there are many theories and ideas. Chronic hyperventilation may have a role, and this condition has been discussed in detail in medical literature for a long time. Central to the method is the theory that respiratory illnesses are a subset of illnesses caused by habitually breathing excessive volumes of air - what Professor Buteyko called "hidden hyperventilation". In particular, Professor Buteyko claimed that the blood of asthmatics contained too little carbon dioxide, but evidence for the role of carbon dioxide as a clinically significant bronchodilator is mixed and its role in asthma disputed.
Also proposed by Professor Buteyko, mineral deficiency and an increasingly sedentary lifestyle are elements that may be involved. Up-to-date theories, such as the balancing of nitric oxide and the production of ANP, have been proposed and studies continue.
Dysfunctional breathing was noted in up to 42% of people in a British study of people with asthma. In these instances, the breathing becomes excessive for metabolic needs and it causes a wide array of symptoms that include the typical asthma symptoms of chest tightness and increased mucus production. This type of thing is noted in most Buteyko workshops, where participants report that their short-acting bronchodilator, such as Ventolin, is not always effective. This is not because of an escalation in the condition due to a chest infection for example, but usually in a one-off situation when Ventolin normally removes the asthma symptoms. On this occasion it does not. It seems likely then that there is either a mis-diagnosis of asthma in some cases, or that the person with asthma mistakes the symptoms of hyperventilation for asthma. By using the Buteyko Method, the person with asthma and/or dysfunctional breathing is usually able to replicate the trial results that all show a huge reduction in asthma symptoms and medication.
The three core principles of Buteyko are reduced breathing, nasal breathing and relaxation.
Reduced Breathing Edit
Almost all of the Buteyko exercises involve slowing breathing rate or reducing breathing volume. The exercises are initially practiced on a regular basis, but are gradually phased out as the condition improves.
Instead of relying solely on peak-flow measurements, Buteyko uses an exercise called the 'Control Pause' (CP) to monitor the status of asthma. The Control Pause can be defined as 'The amount of time that an individual can comfortably hold their breath after a normal exhalation.' As with many physical exercises, performing the CP properly requires practice, and the measurement varies widely from person to person. With regular Buteyko reduced-breathing practice, asthmatics tend to find that their CP gradually increases, and in parallel their asthma symptoms decrease.
Nasal Breathing Edit
The Buteyko method stresses the importance of breathing through the nose, rather than the mouth. Apart from protecting the airways by humidifying, warming, cleaning and sterilizing air entering the lungs, breathing through the nose also reduces the tendency to hyperventilate.
The majority of asthmatics and those who suffer with other breathing disorders have problems sleeping at night. This is known to be linked[How to reference and link to summary or text] with poor posture or unconscious mouth-breathing at night, and there are many devices available designed to encourage nocturnal nasal breathing. By keeping the nose clear and encouraging nasal breathing during the day, night-time symptoms can also improve.
Dealing with asthma attacks is an important factor of Buteyko practice. The first feeling of an asthma attack is scary and often results in a short period of rapid breathing. By controlling this initial ‘over-breathing’ phase, asthmatics can prevent a ‘vicious circle of over-breathing’ developing and spiraling into an asthma attack. This means that asthma attacks may be averted, simply by breathing less.
Note that the method is not a substitute for medical treatment for an asthma attack and reliever medication should be kept handy at all times and used as required. Reduction of medication should be done under supervision of the doctor prescribing the medication, as some steroids and other drugs should not be ceased too quickly. This aspect of Buteyko is merely a change in lifestyle that can minimize the chance of an attack occurring and reduce the severity by remaining calm and in control of breathing.
Clinical Studies Edit
There have been several small clinical studies on Buteyko, and a common thread amongst them is to see a reduction in asthma symptoms and therefore the need for reliever medication after around 1-2 months. A reduction in steroid medication has been observed, but often takes longer. The Buteyko method has not been shown to improve lung function (or peak-flow), which is the conventional measurement of asthma - measuring the current level of constriction in the airways. However, the fact that lung function does not decrease in these trials, despite the reduction in reliever medication, is an important observation.
Some of the earlier Buteyko trials were marred by outside interference from Buteyko groups. This involved telephone 'follow-ups', which Buteyko teachers claimed were standard procedure, but such measures were not taken into account by the control group. However, subsequent trials have taken into account these issues and replicated similar results under strictly controlled conditions.
Slader et al, Thorax, 2006Edit
This is the most recent trial on something that is similar to Buteyko and confirms the findings of previous trials. This was the first trial to use an active control group, by comparing the Buteyko group with a similar, but not identical, set of breathing exercises. The results of the trial were surprising as both groups showed a significant reduction in asthma symptoms. The conclusion states: "Breathing techniques may be useful in the management of patients with mild asthma symptoms who use a reliever frequently, but there is no evidence to favour shallow breathing over non-specific upper body exercises."
The details are as follows: 57 asthmatic volunteers were randomised to one or two breathing techniques learned from instructional videos. The subjects practiced their exercises for 13 minutes, twice daily, for 12 weeks; and as needed for relief of symptoms. Group A exercises were ‘Buteyko-like’. Group B were exercises designed to avoid impact on upper body muscle strength. In both groups reliever use decreased by 86%. Quality of life measurements, lung function and airway responsiveness were unchanged after 14 weeks. The group constructed an in-house device to assess route of breathing and end-tidal CO2 levels, neither of which changed significantly over the course of the trial.
Bowler et al, Medical Journal of Australia, 1998Edit
In 1995 a randomized double blind placebo controlled study on the technique was run in Brisbane, Australia. People in the test were taught either the Buteyko method or a placebo breathing method involving standard physiotherapy relaxation and breathing, and changes in behavior noted. The results of the test showed no improvement in lung function, such as forced expiratory volume in one second or peak flow, in either the Buteyko method group or the placebo group. There was no significant difference between normal breathers and either group at any time, however there was a significant reduction in mean minute volume in the Buteyko group (relative to the placebo group). There was no significant increase in actual CO2.
However, the study detected significant changes in drug use, with the Buteyko group showing a decrease in steroid inhaler use of 49%. To quote the summary of the trial: "Those practising [the Buteyko technique] reduced hyperventilation and their use of beta2-agonists. A trend toward reduced inhaled steroid use and better quality of life was observed in these patients without objective changes in measures of airway calibre." "Quality of life" was measured by a self-administered questionnaire that asked patients about breathing, mood, social interaction and concerns for the future. As the questonnaire relied on subjective information and was not carried out by an independent source, it is possible that it was merely people's perceptions of their own health that was changed.
From the data given the reduction in beta2-agonists (e.g. Ventolin) was 96% and the reduction in steroid inhalers was 49%.
The results were also clouded because it was later learned that the Buteyko group was being telephoned by the Buteyko teacher during the trial. This was unknown to the people carrying out the trial and though it was claimed to be a normal part of the Buteyko process it was not disclosed as such. This leaves open the possibility that people were talked into having their perceptions of their illness changed, which would explain why the Buteyko group showed a change in their drug usage and in their own descriptions of their quality of life, but no changes in physically measurable areas such as airway or lung function. There has been no repeat of the trial to measure the possible influence from outside sources.
Other interesting findings from the Brisbane trial were:
- Neither the Buteyko nor the placebo group experienced a change in carbon dioxide levels after the treatment, but average minute volume for the Buteyko group was significantly lower than for the placebo group, and reduced beta2-agonist use was related to reduction in minute volume.
- Neither group experienced a difference in airway function.
- There was no significant change in the quality of life at any stage of the treatment, though there was a slight trend towards the Buteyko group measuring theirs as better in the long term. The changes in life quality were evenly spread across all areas that were measured.
- There was no significant difference in tidal volume at the end of the trial
- Those who used the Buteyko method used beta2-agonist inhalers less often.
The trial shows that the Buteyko method reduces drug usage without exacerbating the disease, however there are no physical changes to lung function beyond reducing minute volume (which may not be relevant as it is not significantly different to that of normal subjects).
The report states "BBT might also have altered subjects' perceptions of asthma severity without affecting the underlying disease. This could account for the reduction in medication use and trends toward improvements in quality of life and is consistent with the absence of any change in objective measures of airway calibre. On the other hand, the reduction in medication use in the BBT group did not lead to a decline in lung function, and rates of oral steroid use and hospital admission were similar in each group."
In 2000 another trial took place in New Zealand, the aim of which was to measure safety and effectiveness, rather than why Buteyko works. It recorded no change in forced expiratory volume. However, there was an 85% reduction in beta2-agonists and a 50% reduction in steroid use amongst people who had used the Buteyko method for six months. Participants were paired on the basis of severity of asthma. They were then randomised to either Buteyko or control group using a computer-generated list. All participants received a telephone call from their tutor one week after the final teaching session and were instructed to contact their tutor if necessary from this point on. Three contacts were made, two from Buteyko participants and one from the control group. The matched participant was contacted in each case. The term "Buteyko" was allowed in the trial, because it was considered that use of the term would not unduly bias results, and was preferable to unrealistic efforts to maintain complete blinding. The trial recorded no adverse effects from the use of Buteyko. Even though no study has indicated exactly why Buteyko is so effective at controlling asthma, if a drug could show these results, then it is likely that it would be used widely in asthma control.
Bibliography of Russian texts Edit
from the paper by Kazarinov VA
- Buteyko K.P. Oscillogtaphs and Hypertonia. Is "Enhanced" Breathing Beneficial? Izobretatell I Ratsionalizator. 1962. No.5.
- Buteyko K.P. Shurgaya Sh. I.Functional Diagnosis of Coronary Disease. Thesis from Symposium on Surgical Treatment of Coronary Disease, Moscow, 1962.
- Buteyko K.P., Demin D.V. Cross-correlational Analysis of Physiological Functions. Izv. Sib.Otd. AN SSSR. 1963, No.6. Ser.biol.med.nauk.Vypusk Issue) 2.
- Buteyko K.P., Odintsova M.P., Demin D.V. The Influence of Hyper and Hypoxaemia on the Tonus of Peripheral Vessels. Proceeding of the Second Siberia Scientific Conference of Therapists, Irkutsk, 1964.
- Buteyko K.P., Demin D.V., Odintsova M.P. The Application of Regressive Analysis for Differentiation of the Influence of Gaseous Components of the Arterial Blood on the Functional State of Fine Peripheral Arteries. Materialy Vtoroy sib. Nauchnoy Konf. Terapevtov. Irkutsk, 1964.
- Buteyko K.P., Demin D.V.,, Odintsova M.P. The Mathematical Analysis of Interreaction of Physiological tigation Factors. Physics-Mathematical Methods for Inves in Biology and Medicine. Materialy Pervoy Novosib- Conf., Novosibirsk/, 1965.
- Buteyko K.P., Demin Dove,, Odintsova M.P. The Relationship between the Ventilation of the Lungs and the Tone of Arterial Vessels in Patients with Hypertonic Disease and Stenocardia. Fiziologichni Zhurnal, 1965. Vol. II, No.5 (in Ukrrainian).
- Buteyko K.P., Demin D.V., Odintsova M.P. The Relationship between the Carbon Dioxide in Alveoles, Arterial Pressure and Cholesterol in Blood in Patients with Hypertonic Disease and Stenocardia. Materialy Tretley Sib. Nauchn. Conf. Terapevtov. irkutsk, 1965. (Proceedings of the Third Siberian Sci. Conference of Therapists).
- Buteyko K.P. The Cross-Correlational Technique of Analysis of Physiological Regulations. Materialy VII Vsesoyuzn. Conf. po Avtomat. Kontrolyu i Metodam Elektr. Izmereniy. Novosibirsk, 1965, (Proc. of the VII-Union Conference on Automatic Control and Methods for Electrical Measurements).
- Buteyko K.P. The Complex Investigations into Functional Systems in Biology and Medicine. (Reports of the Medical Electronics Section of the 9th Regional Sci.-Tech. Conference Dedicated to the Day of. Radio). Dokl. Sektsii Med. Elektroniki 9-oy Obl. Nauchn.-Tekhn. Conf. Posvyashchennoy Dnyu Radio, Novosibirsk, 1966.
- Buteyko K.P., Demin D.V., Odintsova M.P. The Relationship between the Partial Pressure in Alveolar Air and the Tone of Peripheral Arteries in Patients with Hypertonic Disease and Stenocardia. Zdravookhranenie Turkmenistana. 1966. No.2 (Public Health of Turkmenistan. 1966, No.2).
- Buteyko K.P., Demin D.V., Odintsova M.P. The Effect of Carbon Dioxide on the Coronary Efferent Arteries in Patients with Hypertonic Disease and Atherocardiosclerosis. Zdravookhranenie Kazakhranenie Kazakhstana. 1966. No. 6 (The Kazakhstan Public Health, 1966, No.6).
- Buteyko K.P., Demin D.V., Odintsova M.P. A Linear Model for Regulation of Vascular Tone by Gaseous Components of Arterial Blood. Dokl. 9-oy Obl. Nauchn.-Tekhn. Conf., Posvyashchennoy Dnyu Radio. Novosibirsk, 1966.
- Buteyko K.P. et al. The Influence of Intentional Regulation of Respiration on Some Physiological Functions at Altitude. Voprosy Aviatsionnoy Meditsiny (Problems of Aviation Medicine). Moscow, 1966.
- Buteyko K.P., Chasovskikh S.F.,, Demin D.V. An Indirect Determination of the Degree of Hypertension of Pulmonary Circulation According to the Data of Calibrated Phonocardiography. Materialy 4-oy Povolzhskoy Conf. Fiziologov, Biokhimikov i Farmakologov- Saratov, 1966. T.l. (Proceedings of the 4th Volga River Conference of Physiologists, Biochemists and Pharmacologists. Saratov, 1966, Vol.1).
- Buteyko K.P., Odintsova M.P., Demin D.V. The Influence of Hyper- and Hypoxaemia on the Tone of Arterial Vessels. Sovetskaya Meditsina. 1967. No.3 (Soviet Medicine, 1967. No3) -
- Murakhtanova Z.M., Buteyko K.P. et al. Concerning Characteristic of External Respiration in Patients with Scoliosis. Sbornik Rabot Novosib. Instituta Travmatologii i Ortopedii. Novosibirsk, 1967. (Collection of Reports of the Novosibirsk Institute of Traumatology and Orthopedics. Novosibirsk, 1967).
- Buteyko K.P. et al. The Use of Correlation Methods for Investigation of Cardiovascular System. Mat. Metody v Aviatsionnoy i Kosmicheskoy Meditsine. - Moscow, 1967 (Mathematical Methods in Aviation and Cosmic Medicine).
- Buteyko K.P., Demin D.V., Odintsova M.P. The Mutual Information of Heartrhythm and Other Physiological Human Functions according to the Data of Cross-Correlative Analysis. Mat. Metody Analiza Sergechnogo Ritma. Moscow, 1968 (Mathematical Methods for Analysis of Heart Rhythm. M., 1968).
- Buteyko K.P., Odintsova M.P., Nasonkina P.S. The Ventilation Test for Patients -with Bronchial Asthma. Vrachebnoe Delo, 1968, No.4 (Medical Treatment. 1968, No.4).
- Buteyko K.P., Odintsova M.P. Hyperventilation as One of the Reasons for the Spasm of Nonstriated Musculature of the Bronchi and Arterial Vessels. Materialy 4-oy Nauchn.-Praktich. Conf. po Vrachebn- Kontrolyu i Lechebnoy Fizkulture. Sverdlovsk, 1968 (Proceedings of the 4th Scientific-Practical Conference on Medical Control and Medical Physical Culture. Sverdlovsk, 1968).
- Buteyko K.P. Complex Methods for Investigation of Cardiovascular System and Respiration. Voprosy Funktsionallnoy Diagnostiki. Novosibirsk,, 1969 (Problems of Functional Diagnostics. Novosibirsk, 1969).
- Buteyko K.P. The Theory of CO2-Deficient Diseases of Civilisation as an Adaptation to the Evolution of Atmosphere. Kiberneticheskie Aspekty Adaptatsii Sistemy "Chelovek-Sredall. Tez. Seminars. Moscow, 1975 (Cybernetic Aspects of Adaptation of the System "Man-Environment". Seminar Thesis, M., 1975).
- Buteyko K.P. Therapy of Hemohypocarbia. Patent No.1067640. Registered in the State Record of Inventions of the U.S.S.R., 15.9.1983.
- Buteyko K.P., Genina V.A. Concerning Pathogenesis of Asthma Attack during Physical Exercise. Non-medical Methods for Treatment of Patients with Bronchial Asthma. Tez. Dokl. Vsesoyuzn. Conf. Moscow, 1986 (Report Thesis from the All-Union Conference. M., 1986).
- Buteyko K.P., Genina V.A. The Comparison of Justification and Effectiveness of the Complex, Symptomatic and Monoetiological Principles of Treatment of Bronchial Asthma and Other Allergies. Ibid.
- Buteyko K.P., Genina V.A. The Theory of Discovery of Deep Respiration (Hypervention) as a Main Cause of Allergic,, Bronchial-vascular-spasmodic and Other Diseases of Civilisation. Ibid.
- Buteyko K.P., Genina V.A., Nasonkina N.S The Reactions of Sanogenesis in Medical Treatment Using the ISDR Method. Ibid.
- Putintsev E.V., Varlamova Z.A., Meshcheryakova L.R. Concerning Medical Physical Culture for-Bronchial Asthma. Sb. Materialov k Godichnoy Nauchnoy Sessii Instituta. Novokuznetsk, 1967 (Collection of Reports for Annual Sci. Session of the Institute. Novokuznetsk, 1967).
- Shelomova K.V. Intentional Normalisation of Respiration in the Complex of Medical Physical Culture for Bronchial Asthma. Proceedings of the 4th Sci. -Practical Conf. on Medical Control and Medical Physical Culture. Sverdlovsk, 1968 (as in 22).
- Panova L.A. Bronchial Asthma - a Model of Adaptation to the Changed Environmental Conditions. (As in 24.).
- Gavalov S.M., Genina V.A., Gavalova R.F. Intentional Regulation of Respiration in Complex Medical Treatment of Bronchial Asthma in Children. Saratov, 1976.
- Genina V.A., Glur-,henko I.R. The Construction of a Generalised Indicator of the Bronchial Asthma Condition. Methods for Physical Measurements of Parameters of the Ecological Systems and the Mathematical Processing of the Obtained Data. Novosibirsk, 1982.
- Genina V.A. The Role of Hyperventilation in the Pathogenesis of Bronchial Asthma and Its Medical Treatment by means of Reduction in Ventilation of the Lungs. Epidemiological Characteristics of Non-r.,pecific Diseases of the Lungs in Various Professional Groups. Novosibirsk, 1982.
- Genina V.A. et al. The Medical Treatment of Bronchial Asthma in Children Using the Method of Intentional Normalisation of Respiration (INR) according to the Data of the 1st MMI Children's Clinic. Pediatriya, 1982, No.2 (Pediatrics, 1982, No.2).
- Genina V.A. The Technique for Elimination of Chronic Hyperventilation in the Treatment of Patients with Obstructive Syndrome. Medical Treatment of Non-specific Diseases of the Lungs.
Clinical trials Edit
- Cooper S, Oborne J, Newton S, Harrison V, Thompson-Coon J, Lewis S, Tattersfield A, "Effect of two breathing exercises (Buteyko and Pranayama) in asthma: a randomized controlled trial.", Thorax, VOL 58, 2003, 674-679
- McGowan J, "Health Education: Does the Buteyko Institute Method make a difference?", Thorax, VOL 58/Sup3, December 2003, p28
- Opat AJ, Cohen MM, Bailey MJ, Abramson MJ, "A Clinical Trial of the Buteyko Breathing Technique in Asthma as Taught by Video", J. of Asthma, VOL 37(7), 2000, 557-564
- McHugh P, Aitcheson F, Duncan B, Houghton F, "Buteyko Breathing Technique for asthma: an effective intervention", The New Zealand Medical Journal, VOL 116 No 1187, Dec 2003
- McHugh P, Duncan B, Houghton F, "Buteyko breathing technique and asthma in children: a case series.", The New Zealand Medical Journal, VOL 119 No1234, May 2006
- R.L. Cowie, D.P. Conley, M.F. Underwood, P.G. Reader, "A Randomized Controlled Trial of the Buteyko Technique for Asthma Management", American Thoracic Society Abstracts online. http://www.abstracts2view.com/ats06/view.php?nu=ATS06L_1512
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for disussion on DaCosta's contribution, see: Jacob Mendez Da Costa Who Named It doctor/2452 and Da Costa's syndrome Who Named It synd/2882 as well as Wooley C (1982). Jacob Mendez DaCosta: medical teacher, clinician, and clinical investigator.. Am J Cardiol 50 (5): 1145-8. PMID 6753556.
- Donnelly P (Jan 19 1991). Exercise induced asthma: the protective role of CO2 during swimming.. Lancet 337 (8734): 179-80. PMID 1670821.
- Gayrard P, Orehek J, Grimaud C, CHarpin J (Apr 1975). Bronchoconstrictor effects of a deep inspiration in patients with asthma.. Am Rev Respir Dis 111 (4): 433-9. PMID 123713.
- Guyton AC, Hall JE (1996). "Chemical control of respiration" Textbook of medical physiology, 9th edition, 527-8, WB Saunders. ISBN 0-7216-5944-6.
- Hibbert G, Pilsbury D (Nov 1988). Demonstration and treatment of hyperventilation causing asthma.. Br J Psychiatry 153: 687-9. PMID 3151279.
- Jefferies M (1996). Safe uses of Cortisol, 2nd Edition, Springfield: Charles C.Thomas. ISBN 0-398-06621-3.
- Morgan W (1983). Hyperventilation syndrome: a review.. Am Ind Hyg Assoc J 44 (9): 685-9. PMID 6356858.
- Neill W, Hattenhauer M (1975). Impairment of myocardial O2 supply due to hyperventilation.. Circulation 52 (5): 854-8. PMID 1175266.
- Pfeffer J (1984). Hyperventilation and the hyperventilation syndrome.. Postgrad Med J 60 Suppl 2: 12-5. PMID 6431401.
- Pfeffer J (1978). The aetiology of the hyperventilation syndrome. A review of the literature.. Psychother Psychosom 30 (1): 47-55. PMID 358247.
- Wheatley C (1975). Hyperventilation syndrome: a frequent cause of chest pain.. Chest 68 (2): 195-9. PMID 1149547.
- ↑ McHugh P, Aitcheson F, Duncan B, Houghton F. Buteyko Breathing Technique for asthma: an effective intervention. NZ Med J. 2003;116:1187 PMID 14752538. Free full text
- ↑ Bowler SD, Green A, Mitchell CA. Buteyko breathing techniques in asthma: a blinded randomised controlled trial. Med J Aust. 1998;169(11-12):575-8. PMID 9887897. Free full text
- ↑ 3.0 3.1 3.2 Bowler S, Green A, Mitchell C (Dec 7-21 1998). Buteyko breathing techniques in asthma: a blinded randomised controlled trial.. Med J Aust 169 (11-12): 575-8. PMID 9887897.
- ↑ Slader C, Redde H, Spencer L, Belousova E, Armour C, Bosnic-Anticevich S, Thien F, Jenkins C. Double blind randomised controlled trial of two different breathing techniques in the management of asthma. Thorax 2006;61:651 PMID 16517572. Free full text
- ↑ 5.0 5.1 McHugh P, Aitcheson F, Duncan B, Houghton F (2003). Buteyko Breathing Technique for asthma: an effective intervention.. N Z Med J 116 (1187): U710. PMID 14752538.
- ↑ Kazarinov VA (1990). "[The biochemical basis of KP Buteyko's theory of the diseases of deep respiration]" Ed. Buteyko KP [Buteyko Method: The experience of implementation in medical practice] (Translation from Russian), 198-218, Moscow: Patriot Press.
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- http://www.buteykobreathing.org Buteyko Breathing Association, UK
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