Prevalence of dysfunctional breathing in patients treated for asthma in primary care: cross sectional survey
BMJ 2001; 322 doi: https://doi.org/10.1136/bmj.322.7294.1098 (Published 05 May 2001) Cite this as: BMJ 2001;322:1098
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We found the results of Thomas et al interesting but unsurprising.
We have used the Nijmegan questionnaire as part of an audit to evaluate
respiratory intervention in out patients presenting with dysfunctional
breathing.
Following a course of physiotherapy treatment, including education,
relaxation, breathing control and exercise, all patients showed an
improvement in their Nijmegan questionnaire (p=0.0001) and we noted a
reduction in respiratory rate.
In an attempt to measure the ‘avoidable morbidity’ described by
Thomas et al (2001) we used two visual analogue scales (VAS) measuring
perceived breathlessness and degree of ‘bother’. The VAS relating to how
much the patients’ breathing troubled them was reduced significantly
(p=0.0014) following treatment. Patients were less ‘bothered’ by their
breathing and this may demonstrate that our patients are better able to
cope with their breathing disorder, even if other objective measures, such
as the Nijmegan questionnaire and resting respiratory rate, showed less
improvement.
The suggestion that patients experienced an improvement in their
quality of life following their course of treatment was supported by the
positive comments we received, although not formally measured.
We agree with Thomas et al that effective intervention exists and our
audit shows that respiratory physiotherapy is an important component in
the diagnosis and management of these patients.
Further research of these interventions is needed in the form of a
randomised-controlled trail.
Competing interests: No competing interests
Editor- Thomas et al (1) recently showed that 29% of asthmatic patients in general practice have a high score on Nijmegen questionnaire, indicating the presence of dysfunctional breathing and suggesting scope for therapeutic intervention. Their point is that asthmatic breathlessness may coexist with breathlessness due to dysfunctional breathing and respond to breathing therapy, which has been shown to reduce complaints on Nijmegen questionnaire (2).
Keeley and Osman, in their critical comment (3), misunderstood this point and assumed that the authors meant that 29% was wrongly diagnosed. Furthermore, Keeley and Osman equated dysfunctional breathing and hypocapnia. The authors however tried to avoid this very equation, which reduces all breathing abnormalities to hyperventilation, by using the term dysfunctional breathing. This refers to unnecessary tension in breathing, unrelated to the extent of the somatic illness.
It has recently been shown to be also present in patients with lung cancer and respond to proper treatment, including breathing and relaxation therapy (4). I feel therefore that the next step of Thomas et al is valid, that is to assess the response to breathing therapy. A positive response includes a shift towards a more functional breathing pattern and a reduction of complaints on Nijmegen questionnaire. This confirms dysfunctional breathing to be a cause of complaints. It is different from psychological help to patients with asthma to cope with anxiety, that Keeley & Osman advice.
1. Thomas M, McKinley RK, Freeman E, Foy C. Prevalence of dysfunctional breathing in patients treated for asthma in primary care: cross sectional survey. Brit Med J 2001; 322: 1098 1100.
2. Han JN, Stegen K, DeValck C, Clement J, van de Woestijne KP. Influence of breathing therapy on complaints, anxiety and breathing pattern in patients with hyperventilation syndrome and anxiety disorders. J Psychosom Res 1996; 41:481-93.
3. Keeley D, Osman L. Dysfunctional breathing and asthma. Brit Med J 2001; 322:1075-6.
4. Bredin M, Corner J, Krishnasamy M, Plant H, Bailey C, A'Hern R. Multicentre randomised controlled trial of nursing intervention for breathlessness in patients with lung cancer. Brit Med J 1999; 318:901-4.
Competing interests: No competing interests
Effective therapy for panic disorder should be acknowledged in
discussion of treatment for dysfunctional breathing.
Thomas et al [1] report an appreciable prevalence of dysfunctional
breathing in adults with asthma and discuss the scope for wider use of
breathing therapy. Neither investigators nor the authors of the
accompanying editorial [2] consider whether such symptoms might occur
equally frequently in the normal population or represent panic attacks/
disorder, well defined entities common in otherwise healthy people.
Without a control group their study is incapable of identifying the
prevalence of dysfunctional breathing associated specifically with asthma.
Dysfunctional breathing and the hyperventilation syndrome are by no
means the same as panic syndromes, but overlap between them may be
considerable. Thomas et al acknowledge limitations of the Nijmegen
Questionnaire [3]. Notably, the instrument cannot differentiate the
"chimeric" hyperventilation syndrome from the well-defined phenomena of
panic attacks and panic disorder. The sixteen items in the Nijmegen
questionnaire include "anxiety", "feeling tense" and 9 of the 13 panic
attack symptoms listed in DSM-III-R. The questionnaire was not defined to
attempt to make this distinction. A 23% lifetime prevalence of
spontaneous panic attacks has been reported in asthmatics [4]. This figure
is not dissimilar to the 29% of asthmatics labelled by Thomas et al as
having experienced dysfunctional breathing, and again suggests appreciable
overlap. The lifetime prevalence of asthmatics meeting DSM-III-R criteria
for panic disorder in the same study was 9.7% [4].
We reported a significant excess of panic attacks and panic disorder
among primary care and hospital patients with hypertension compared to
matched normotensives, and 202 of 287 people who had experienced panic
attacks related "shortness of breath" or "difficulty catching breath" as
being symptoms in their worst panic attack [5]. The relation of history of
panic attacks to gender in our sample was strikingly similar to that
reported for dysfunctional breathing [1], with a significant excess in
females of around 15% in both studies.
The importance of considering panic disorder in a discussion of
dysfunctional breathing lies in the availability of treatment of proven
efficacy. Thomas et al limit their consideration of therapeutic
intervention to breathing therapy. In a patient with recurrent difficult
breathing and history suggestive of panic disorder, a much broader range
of treatment, from tricyclic antidepressants and selective serotonin
reuptake inhibitors to cognitive therapy may be effective. Failure to
identify panic attacks or panic disorder may deprive patients of valuable
treatment options, some of which can be instigated in primary care.
Dr Simon JC Davies,
Senior House Officer,
Bristol, Bath and Weston
Psychiatry Rotation.
Dr Peter R Jackson,
Reader and Honorary Consultant,
Clinical Pharmacology and Therapeutics, University of Sheffield.
Professor
Lawrence E Ramsay,
Clinical Pharmacology and Therapeutics, University of
Sheffield.
REFERENCES
[1] Thomas M, McKinley RK, Freeman E, Foy C. Prevalence of
dysfunctional breathing in patients treated for asthma in primary care:
cross sectional survey. BMJ 2001; 322: 1098-1100.
[2] Keeley D, Osman L. Dysfunctional breathing and asthma. BMJ 2001;
322: 1075-6.
[3] van Dihoorn J, Duivenvoorden HJ. Efficacy of Nijmegen
Questionnaire in recognition of the hyperventilation syndrome. J Psychosom
Res 1985; 29: 199-206.
[4] Carr RE. Lehrer PM, Rausch LL, Hochron SM. Anxiety sensitivity
and panic attacks in an asthmatic population. Behav Res Ther 1994; 32: 411
-8.
[5] Davies SJC, Ghahramani P, Jackson PR, Noble TW, Hardy P,
Hippisley-Cox J, Yeo WW, Ramsay LE. Association of panic disorder and
panic attacks with hypertension. Am J Med 1999; 107: 310-6.
Competing interests: No competing interests
Editor - Thomas et al. (1) must be complimented on drawing attention
to the important issue of hypocapnic breathing in asthma. An editorial
pointed out a lack of validation of the Nijmegen questionnaire for an
asthmatic population (2), but a more general problem of questionnaire
research is becoming apparent. The multi-dimensionality of symptom
reporting in asthma has been demonstrated by Kinsman and others in
research on the Asthma Symptom Checklist (ASC; 3), but this fact is not
reflected in recent developments of health status measures that measure
symptoms as part of a broader range of indicators of treatment outcome or
quality of life in asthma (4). The strength of these instruments lies in
their ability to gauge overall health status, but in some contexts more
specific instruments are needed for measuring particular aspects of health
status such as symptoms. For example, when the aim is to identify
subgroups of asthma patients with distinct symptom patterns such as
dysfunctional breathing, psychometrically validated high fidelity symptom
report measures are needed.
Unfortunately, the Nijmegen questionnaire does not provide
information of sufficient quality in bronchial asthma. The cut-off score
of >=23 for the diagnosis of ‘dysfunctional breathing’ could
theoretically be reached by maximum or near maximum values on seven items
related to typical asthmatic airway obstruction symptoms (‘shortness of
breath’, ‘tightness across chest’, ‘fast or deep breathing’) and states of
anxiety (‘feeling tense’, ‘cold hands or feet’, ‘palpitations in the
chest’, ‘anxiety’), without being indicative of hyperventilation. Other
items on the questionnaire have a greater face validity for
hyperventilation in asthma. It would be useful to examine the factorial
structure of the Nijmegen questionnaire in asthmatics. It is conceivable
that this would reveal factors corresponding to the symptom dimensions
already identified by Kinsman et al. in the ASC, such as panic-fear,
obstruction, and hyperventilation. Although these and other symptom
dimensions are often moderately correlated, questionnaire scales based on
these dimensions could provide more valid criteria for identifying those
asthma patients who really suffer from hypocapnic breathing, not only from
the typical airway obstruction and ensuing anxiety. Ultimately, only
ambulatory recording of symptoms and PCO2 levels in daily life will reveal
the real prevalence of hypocapnic breathing in asthma.
(1) Thomas M, McKinley RK, Freeman E, Foy C. Prevalence of
dysfunctional breathing in patients treated for asthma in primary care:
cross sectional survey. BMJ 2001; 322:1098-100.
(2) Keeley D, Osman L. Dysfunctional breathing and asthma. BMJ 2001;
322:1075-6.
(3) Kinsman RA, Luparello T, O’Banion K, Spector S. Multidimensional
analysis of the subjective symptomatology of asthma. Psychosom Med 1973;
35:250-67.
(4) Richards JM, Hemstreet MP. Measures of life quality, role
performance, and functional status in asthma research. Am J Respir Crit
Care Med 1994; 149: S31-9.
Competing interests: No competing interests
EDITOR- By connecting dysfunctional breathing in asthma with the
anxiety related hyperventilation syndrome Thomas et al (1) may have
inadvertently led to some misunderstanding regarding the intended role of
breathing exercises such as Buteyko in the treatment of this condition.
Physiological hyperventilation is a common finding in patients with
mild, symptomatic asthma as shown by a raised minute volume of
respiration, lowered arterial pCO2 and consequent respiratory
alkalosis(2,3). However, this does not in itself imply that such patients
are
suffering from excessive anxiety. In many cases the desire of an asthmatic
patient to breathe deeply can be seen as a natural response to the feeling
of restricted breathing. This is entirely analogous to the way in which a
patient with eczema develops a habit of scratching, or a patient with
mechanical back pain adopts an abnormal posture. In each case the
patient's own behaviour, whilst understandable, can nevertheless lead to
an exacerbation of the underlying condition.
Reviewing the literature there is substantial evidence that
hyperventilation in itself can lead to significant increases in the
resistance of human airways (4). Several possible mechanisms have been put
forward to explain this including stimulation of autonomic reflexes
or even as a direct effect of lowered carbon dioxide levels. The emphasis
of breathing pattern modification is therefore directed towards the
prevention of such hyperventilation induced bronchospasm. The crucial
point is that this approach is effective irrespective of whether or not
the underlying hyperventilation is related to anxiety.
This latter point is entirely consistent with my own experience of
teaching the Buteyko method which has shown that the majority of well
motivated, asthmatic patients derive significant benefit in terms of
improved symptom control and reduction in medication use. In particular,
although entirely subjective, my impression is that less anxious patients
tend to respond more favourably.
We all know that changing patients' behaviour can be difficult.
Therefore any attempt must be well-organised and involve adequate support.
However, taking into account the current high expenditure on asthma I
believe that the Buteyko method offers a serious and cost effective
adjunct to conventional care. It should not simply be seen as
treatment reserved for the worried well.
James Oliver
General Practitioner
Mullion Health Centre, Cornwall TR12 7HS
oliver@kerdevez.demon.co.uk
1. Thomas M, McKinley RK, Freeman E, Foy C. Prevalence of
dysfunctional breathing in patients treated for asthma in primary care:
cross sectional survey. BMJ 2001;322:1098-100
2. Tobin MJ, Tejvir SC, Jenouri G, Birch SJ, Hacik B, Gazeroglu BS,
Sackner MA. Breathing Patterns 2. Diseased subjects. Chest 1983;84(3):286
-94
3. McFadden ER, Lyons HA. Arterial blood gas tension in asthma. NEJM
1968;278:1027-1032
4. Sterling GM. The mechanism of bronchoconstriction due to
hypocapnia in man. Clin. Sci. 1968;34:277-285
Competing interests: No competing interests
Editor,
Thomas et al studied the prevalence of dysfunctional
breathing in patients treated for asthma in the primary care setting(1).
This interesting study has highlighted an important area for further
research.
Keeley and Osman’s comments regarding the validity of Nijmengen
questionnaire and the authors’ interpretation of the results were highly
relevant(2). We would like to raise some additional points.
Population variations in socioeconomic status, smoking rates,
pollution exposure and concurrent lung disease may affect the prevalence
of asthma and dysfunctional breathing. Therefore, as a single centre
study, we doubt that these results can be applied to a general population.
It is important to know the prevalence of dysfunctional breathing in
asthmatics, but these data are only meaningful in relation to the
prevalence in the general population.
We believe that further research could take the form of a larger
cross-sectional study. This would allow comparison of the prevalence of
dysfunctional breathing in asthmatics and the general population, as well
as the investigation of other variables. A multi-centre study will take
account of these regional population variations. The diagnosis of
dysfunctional breathing should be made using both anxiety and symptom-
based questionnaires, rather than the Nijmengen alone. Such a study would
cast further light on an area where uncertainty over diagnosis and
management exists.
Matthew A Garner
Daniel Hedwat
Katharine E Neville-Smith
James A Shand
Dominic P Waddington
Third Year Medical Students
Department of Epidemiology and Public Health,
The Medical School, University of Newcastle upon Tyne
1. Mike Thomas, R K McKinley, Elaine Freeman, Chris Foy, Prevalence
of dysfunctional breathing in patients treated for asthma in primary care:
cross sectional survey
BMJ 2001;322:1098-1100
2. Keeley, D., Osman, L. Dysfunctional breathing and asthma. BMJ
2001;322: 1075-1076
Competing interests: No competing interests
Authors' reply
Editor,
We would like to thank the authors of the editorial and letters for
their interest in our work(1). In their editorial, Keeley and Osman agree
that people with asthma may experience functional breathing problems. They
maintain that our study overestimates the problem yet make no reference to
data to support their assertion(2). They are correct in that the Nijmegen
Questionnaire has not been validated in asthmatic populations, but neither
has it has it been specifically validated for any disease sub-group. Four
questions relate to respiratory symptoms which may occur in asthma but six
questions relate to symptoms common to cardiac, five to neurological and
four to psychiatric conditions. Ritz comments on the multidimensionality
of the symptoms experienced by people with asthma and Davies et al on the
excess of panic disorder in people with asthma, which may further confound
this problem. Our view is that the questionnaire examines a constellation
of symptoms that are common to several disease processes but suggest the
presence of dysfunctional breathing when they occur together. Research is
needed into optimal methods of diagnosis, whether by ambulatory
capnography or by the response of people with asthma and symptom scores
suggestive of dysfunctional breathing to specific therapies.
We do not however suggest that these people who may have
dysfunctional breathing do not have asthma. We agree with van Dixhoorn
that asthma and dysfunctional breathing may co-exist, and are not
suggesting widespread mis-diagnosis of asthma. Nevertheless it is possible
that symptoms due to dysfunctional breathing may be mis-attributed to
asthma, and further studies which include objective measures of asthma,
such as bronchial hyper-reactivity and sputum eosinophilia, in patients
labelled as asthma who have symptoms suggestive of dysfunctional breathing
are needed. Such studies should be multicentred and determine the
prevalence of dysfunctional breathing in the general population (thought
to be 6-10% (4)) and in those who have asthma, as Garner et al and Davies
et al have suggested.
Keeley and Osman state that breathing exercises have not been proven
to be of benefit in asthma, although a recent Cochrane review of breathing
exercises in asthma(3) concluded that the evidence is insufficient rather
than absent. We therefore welcome the data presented by Johnson and Crosby
indicating that physiotherapy based breathing retraining can improve the
quality of life of patients with respiratory disease and co-existing
dysfunctional breathing, and agree that well designed randomised
controlled trials are needed.
Oliver comments on the Butekyo method of treating asthma. Studies are
needed to determine its benefits and compare them with those which may be
achieved by other interventions either pharmalogical or non-pharmalogical
We feel that our study and the correspondence raise rather than
answer questions, and point towards the need for further research.
Nevertheless they raise the possibility that an important minority of
people treated for asthma in the community may be helped by simple non-
pharmacological interventions which should be investigated.
Dr M Thomas, Department of Primary Care, University of Aberdeen and
Minchinhampton Surgery, Stroud, Gloucestershire GL6 9JF
RK McKinley, Department of General Practice and Primary Health Care,
University of Leicester
1. Thomas M, McKinley RK, Freeman E, Foy C. Prevalence of
dysfunctional breathing in patients treated for asthma in primary care:
cross sectional survey. BMJ 2001;322:1098-100.
2. Keeley D,.Osman L. Dysfunctional breathing and asthma. BMJ
2001;322:1075-6.
3. Holloway E and Ram FSF. Breathing exercises for asthma (Cochrane
review). The Cochrane Library Issue 3. 2000. Oxford, Update Software.
4. Vansteenkiste J, Rochette F, Demedts M. Diagnostic tests of
hyperventilation syndrome. Eu Respir J 1991;4:393-9.
Competing interests: No competing interests