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Chest Physiotherapy Does Not Induce Bronchospasm in Stable Asthma
714
Key Words Asthma, chest physiotherapy, airway secretion, pulmonary function tests.
Chest Physiotherapy Does Not Induce Bronchospasm in Stable Asthma
by Viviani Barnabé Beatriz Saraiva Rafael Stelmach Milton A Martins Maria do Patrocínio T Nunes
Study objectives A recent systematic review concluded that it is not possible to judge manual chest physiotherapy safety in asthma. This study measured the effects of chest physiotherapy on pulmonary function and symptoms and safety in people with stable asthma. Design Prospective controlled study. Setting University general hospital. Patients Eighty-one asthma patients attending an asthma clinic with stable asthma, 62 adults and 19 children, and 15 adults without asthma recruited from members of staff of the hospital. Interventions Spirometry was performed before and five minutes after chest physiotherapy, which included postural drainage, percussion, vibratory-shaking and the forced expiration technique – ‘huffing’. Measurements and results There were no significant changes in FEV1 and FEF25-75% induced by chest physiotherapy in adults with mild and moderate or severe asthma and in children with mild and moderate asthma. After chest physiotherapy there was no decrease in FEV1 greater than 20%. Of the children 32% and of the adults 4% complained of worsening in asthma symptoms after physiotherapy manoeuvres. However, FEV1 did not decrease more than 10% in any of them. Eight hours after treatment, participants with moderate asthma did not show a significant change in FEV1. Conclusions Chest physiotherapy manoeuvres, including postural drainage, percussion, vibratory-shaking and ‘huffing’, do not induce a significant worsening in airway obstruction in subjects with stable asthma, including patients with severe asthma.
Barnabé, V, Saraiva, B, Stelmach, R, Martins, M A and Nunes, M do P T (2003). ‘Chest physiotherapy does not induce bronchospasm in stable asthma’, Physiotherapy, 89, 12, 714-719. Physiotherapy December 2003/vol 89/no 12
Introduction Chest physiotherapy is effective in enhancing the clearance of tracheobronchial secretions and helping in the promotion of pulmonary rehabilitation in several pulmonary diseases (Barnes, 1994). Chest physiotherapy usually includes various combinations of postural drainage, percussion, vibratory-shaking, breathing exercises, directed coughing and the forced expiration technique (‘huffing’). Chest physiotherapy has been indicated in patients with mucus hypersecretion, with the exception of asthma, where it has been reported to induce bronchospasm (Barnes, 1994). However there is a dearth of literature in this area, particularly with relevance to acute asthma. In an exacerbation of asthma as a result of factors such as viral or bacterial infection, allergen exposure and climate changes, bronchospasm, vasodilatation with peribronchiolar and perivascular oedema and mucus hypersecretion occur (NIH, 1997). However, the role of chest physiotherapy in these circumstances remains unclear (Zudaire et al, 2000). Chest physiotherapy in various forms is thought to be of some benefit in asthma, possibly through airway secretion mobilisation and thoracic muscular relaxation (Orlandi et al, 1989; Eid et al, 1991). However, Hondras et al (2000) and Ernst (2000), in a recent systematic review of manual therapy for asthma, concluded that ‘currently there is insufficient evidence to support or to refute the use of manual therapy for patients with asthma’. It has been considered that in status asthmaticus the increased stimulation induced by chest physiotherapy may worsen a patient's unstable condition, as a consequence of bronchial hyperresponsiveness (Barnes, 1994). In addition, it has been observed that percussion
Research report
may induce bronchospasm in chronic pulmonary diseases (Campbell et al, 1975; Feldman et al, 1979). However, there are many chest physiotherapy manoeuvres that have not been evaluated extensively in asthmatic patients (Hondras et al, 2000; Asher et al, 1990). Chest percussion, shaking, vibration and postural drainage have been postulated as increasing the mobilisation of bronchial secretions to more central airways for expectoration by coughing (Eid et al, 1991). Since these procedures have not been studied before in asthmatic patients, it is necessary to assess the safety of these manoeuvres, initially in clinically stable patients. The purpose of the present study was to evaluate pulmonary function and symptoms before and after chest physiotherapy, in people with stable asthma, in order to study the potential bronchospastic effects of these manoeuvres. Patients and Methods The protocol was approved by the institutional Ethics Review Committee. Each of the subjects, or the parents in the case of children, gave written informed consent. Study Population Sixty-two stable adult asthmatic patients and 19 asthmatic children entered the study. These subjects were recruited from patients attending the Asthma Centre of the Clinics Hospital of the University of São Paulo. They were classified as having mild, moderate or severe asthma, according to National Institute of Health criteria (NIH, 1997). They were included in the study if they were considered stable by their physicians and had not had any asthma exacerbation in the previous four weeks. Fifteen non-asthmatic subjects followed the same protocol of chest physiotherapy and served as controls. They were recruited from staff members of the Asthma Centre. Abbreviations
FEV1 - forced expiratory volume in the first second of forced vital capacity FEF25-75% - forced expiratory flow at 25-75% of vital capacity
715
Four groups were studied: ■ A control group of adults without asthma (n = 15). ■ Adults with mild and moderate stable asthma (n = 50). ■ Children with mild and moderate asthma (age 6-12 years, n = 19). ■ Adults with severe asthma (n = 12). Measurement of Pulmonary Indices Spirometry was performed on all subjects according to American Thoracic Society guidelines (1995), using a spirometer (Koko, PDS Instrumentation Inc, Louisville, CO) before and five minutes after chest physiotherapy. Peak expiratory flow rate was also measured with a peak flow meter (Mini-Wright, Clement Clark International, Essex). Study Design Bronchodilators were suspended six hours before measurement. All subjects had baseline spirometric measurements taken. Patients completed a short questionnaire in which they were asked if they were currently experiencing symptoms of asthma including respiratory distress, cough or chest tightness. Subsequently each subject under went a non-stop 15-minute period of chest physiotherapy: ■ For the first 14 minutes the patients were seated in a position where the thorax was inclined forwards by 45˚ (position of postural drainage for the posterior segment of the superior lobe) where percussion and vibratoryshaking were performed. ■ Subsequently they were seated upright against the backrest of the chair (position of postural drainage for the apical segment of the superior lobe) where percussion and vibratoryshaking were performed. ■ Finally, still seated but with the thorax inclined backwards by 45˚ (position of postural drainage for the anterior segment of the superior lobe) the same manoeuvres were repeated. In the last minute the forced expiration technique was undertaken. ■ Five minutes after manual therapy, patients were asked if their asthma symptoms – respiratory distress, cough and/or chest tightness – were better, worse or unchanged, and further spirometric measurements were taken.
Authors Viviane Barnabé MSc is a physiotherapist instructor in the School of Physiotherapy, UNICID, São Paulo, Brazil. Beatriz Saraiva MSc is a research associate and Maria do Patrocínio T Nunes MD PhD is assistant professor in the School of Medicine, University of São Paulo, Brazil. Rafael Stelmach MD is a staff physician in the Division of Pulmonary Diseases and Milton A Martins MD PhD is a professor of medicine and director of the Division of General Internal Medicine, at the Clinics Hospital, University of São Paulo, Brazil. Authors’ Contribution Viviane Barnabé participated in experimental design, data collection and analysis and writing of the manuscript. Beatriz Saraiva participated in data collection and analysis and reviewed the final manuscript. Rafael Stelmach participated in experimental design and reviewed the final manuscript. Milton A Martins participated in experimental design, data analysis and writing of the manuscript. Maria do Patrocínio T Nunes participated in experimental design, data collection and analysis and writing of the manuscript.
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Eight hours later, peak expiratory flow rate was recorded in adults with mild and moderate asthma (n = 50) to evaluate the potential late effects of physiotherapy on lung function. People in this group had not used bronchodilators in the six hours before chest physiotherapy, to avoid confounding effects on peak expiratory flow rate. Statistical Analysis Comparisons of pulmonary function tests before and after chest physiotherapy were performed using paired Student’s t-test. A one-way repeated measures analysis of variance was used to study the peak expiratory flow rate values obtained before, immediately after and eight hours after chest physiotherapy. Frequency analysis was used to evaluate the possible categories of answer for clinical symptoms in the four groups. The results are expressed as means ± standard error. Statistical analysis was performed using SigmaStat 2.1 software (Jandel Corp, San Rafael, CA). A value of p < 0.05 was considered significant. Results Table 1 shows demographic data of the four groups studied. All subjects completed the study. No decrease in FEV1 of more than 20% of control values was noted in any subject during the study. In fact, only two children and seven adults demonstrated a decrease in FEV1 greater than 10% (110 to 280 ml for adults). Table 1: Clinical characteristics and demographic data of studied subjects Subjects
N Age (mean ± SEM) (mean ± SEM)
Non-asthmatic subjects
15
Years of asthma
24.2 ± 2.1
Mild and moderate asthma
50
24.9 ± 2.3
15.0 ± 2.2
Severe asthma
12
40.5 ± 17.7
18.9 ± 10.3
Mild and moderate asthmatic children 19
9.7 ± 2.5
7.6 ± 3.2
Table 2: Percentage of answers related to chest symptoms after chest physiotherapy Subjects
Worse
Unchanged Better
Non-asthmatic subjects (n = 15)
0
47
Mild and moderate asthma (n = 50)
4
53
42
Severe asthma (n = 12)
0
36
64
Mild and moderate asthmatic children (n = 19) 32
21
47
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Figure 1 shows the mean values of forced expiratory volume in one second (FEV 1 , percent predicted) before and five minutes after chest physiotherapy in the four groups studied. There was no significant change in FEV 1 induced by chest physiotherapy in the four groups studied, although a trend was observed for higher values of FEV 1 after chest physiotherapy in the control group, in the group of adults with severe asthma, and in asthmatic children. Figure 2 shows forced expiratory flow at 25-75% of vital capacity (FEF25-75). Higher values of FEF25-75 after chest physiotherapy were observed in the control group, children with asthma and severe asthmatics, but these differences were not statistically significant. Figure 3 shows values of patients’ peak expiratory flow with mild or moderate asthma measured before, five minutes after and eight hours after chest physiotherapy. There was no significant change in peak expiratory flow values induced by chest physiotherapy. Additionally, peak expiratory flow rate did not decrease by more than 20% of the baseline values. Chest physiotherapy was well tolerated by patients with asthma. Only two adults and six children with asthma reported worsening in symptoms after chest physiotherapy (table 2). However, the asthmatics who complained of worsening in symptoms demonstrated a decrease in FEV 1 no greater than 10% when compared with their baseline values. Discussion In this study, chest physiotherapy was well tolerated by people with stable asthma. The majority of patients reported feeling unchanged or even improved immediately after chest physiotherapy (table 2). More importantly, even patients with severe asthma demonstrated no significant decrease in FEV 1 or peak expiratory flow rate induced by chest physiotherapy. Only two adults (4.3%) reported worsening of symptoms. The percentage of children who complained of worsening in symptoms was higher (31.5%). However, none of these children demonstrated a decrease in FEV1. Since they were not used to chest physiotherapy, it is possible that some of their symptoms were due to discomfort induced by the manoeuvres used. Asthma has been described as a possible
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Key to all figures Before chest physiotherapy
FEV1 (% predicted)
contra-indication to chest physiotherapy along with critical illness, spinal cord trauma and intra-cranial hypertension (Orlandi et al, 1989). Few previous studies of asthmatic patients involve chest physiotherapy (Pryor and Webber, 1979). Based on such data, Ernst (2000) concluded that it is not possible to judge the effects of chest physiotherapy in asthma. According to the Guideline for the Management of Asthma of the British Thoracic Society (2003), since the number of studies is very small, it is not possible to make an evidence-based recommendation about breathing exercises for asthma. To our knowledge, no previous studies have been reported which evaluated whether chest physiotherapy manoeuvres, such as postural drainage, percussion, vibratoryshaking and the forced expiration technique (‘huffing’), resulted in airway obstruction in stable asthmatics. The manoeuvres utilised in the present study have been used to assist removal of excess tracheobronchial secretions in patients with various pulmonary diseases (Orlandi et al, 1989; Eid et al, 1991). Our results suggest that these manoeuvres are safe for patients with stable asthma. However, this study was not designed to evaluate the effectiveness of chest physiotherapy in asthma, but merely the safety of such manoeuvres in this kind of patient. Another limitation of this study was that only stable asthmatics were evaluated. It is possible that the effects of these manoeuvres could be more intense in people with unstable asthma, where the amount of mucus produced in the airways is greater. However, the safety of these procedures has yet to be demonstrated in people with unstable asthma. Because of the potential for chest physiotherapy to provoke bronchospasm, these techniques are not usually indicated in emergency rooms or intensive care units for unstable, mucus producing asthmatic patients (Barnes, 1994; Campbell et al, 1975; Feldman et al, 1979). In addition, Zudaire
80
60
40
20
Control group
Mild/moderate asthma
Severe asthma
Children with asthma
Fig 1: Mean FEV1 before and after chest physiotherapy. There were no significant differences in FEV1 values induced by chest physiotherapy in the four groups studied. Bars indicate standard errors
100 FEV25-75% (% predicted)
8 hours after chest physiotherapy
80
60
40
20
Control group
Mild/moderate asthma
Severe asthma
Children with asthma
Fig 2: Mean FEF25%-75% before and after chest physiotherapy. There were no significant differences in FEF25%-75% values before and after chest physiotherapy in the four groups studied. Bars indicate standard errors 600
500 Peak expiratory flow (L/min)
5 minutes after chest physiotherapy
100
400
300
200
100
Mild and moderate asthmatics
Fig 3: Mean values of peak expiratory flow rate for patients with mild or moderate asthma, measured before and after chest physiotherapy. There were no significant differences in peak expiratory flow rate values before, immediately after and eight hours after chest physiotherapy. Bars indicate standard errors
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Address for Correspondence Maria do Patrocínio T Nunes MD, Faculdade de Medicina da Universidade de São Paulo, Av Dr Arnaldo, 455 sala 1216, 01246-903 – São Paulo – SP, Brazil. E-mail [email protected] Presentation This study was presented in part at the meeting of the European Respiratory Society in Geneva, Switzerland, in 1998. Acknowledgements We would like to thank the physicians, physiotherapists, nurses, biologists and secretaries of the Asthma Centre of the Hospital das Clínicas of the University of Sao Paulo for their help in this study.
et al (2000) reported the appearance of a pneumothorax immediately after chest physiotherapy in a four-year-old girl with status asthmaticus, suggesting that caution should be exercised. It is also possible that due to the small size of three of the subject groups the power of the analysis may have been insufficient to detect a difference, even if one had been present. However, the similarities in the responses of all four groups suggests that some confidence can be placed in these trends. The overall power in the analysis of variance was 80%. We observed that chest physiotherapy did not induce or worsen bronchospasm in healthy subjects or stable asthmatic patients. In contrast, an enhancement in pulmonary function was observed in some subjects. An improvement in pulmonary function could be explained as the result of thoracic muscular relaxation, a possible increase in airway secretion mobilisation and also possibly some learning effects (Eid et al, 1991; Barnes, 1994). Thoracic muscular contraction is, at least partially, due to the inadequate use of the diaphragm muscle in asthma. This weak performance results in overuse of the accessory respiratory muscles
(Goldman and Mead, 1973; Celli, 1986). Thoracic muscular relaxation results in better pulmonary mechanics and in a decrease of respiratory load (Gilmartin and Gibson, 1986; Kakizaki et al, 1999). Air way secretion mobilisation, as a consequence of thoracic percussion, is thought to facilitate airflow in the airways, which in turn results in better pulmonary ventilation (Bateman et al, 1979). An improvement of respiratory symptoms as described by 43% to 64% of asthmatic patients after chest physiotherapy was observed. This finding could be explained by the occurrence of chest wall muscle relaxation secondary to the physiotherapy manoeuvres. Conclusion Our results suggest that chest physiotherapy manoeuvres such as postural drainage, percussion, vibratory-shaking and the forced expiration technique (‘huffing’) are safe in people with stable asthma, including those with severe asthma. Clinical trials with chest physiotherapy in episodes of asthma exacerbation must be conducted in order to establish safety and effectiveness in the wider asthmatic population.
References Funding This study was supported by the following Brazilian Scientific Agencies: Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) and Programa de Núcleos de Excelência (PRONEX-MCT).
American Thoracic Society (1995). ‘Standardisation of spirometry: 1994 update’, American Journal of Respiratory Critical Care Medicine, 152, 1107-36. Asher, M I, Douglas, C, Airy, M et al (1990). ‘Effects of chest physical therapy on lung function in children recovering from acute severe asthma’, Pediatric Pulmonology, 9, 146-151.
Eid, N, Buchheit, J, Neuling, M et al (1991). ‘Chest physiotherapy in review’, Respiratory Care Medicine, 36, 270-282. Ernst, E (2000). ‘Breathing techniques: Adjunctive treatment modalities for asthma: A systematic review’, European Respiratory Journal, 15, 969-972.
Barnes, T A (1994). Core Textbook of Respiratory Care Practice, Mosby Yearbook, Missouri, 2nd edn, 203-240.
Feldman, J, Traver, G A and Tanssig, C M (1979). ‘Maximum expiratory flows after postural drainage’, American Review of Respiratory Disease, 119, 239-245.
Bateman, J R M, Newman, S P, Daunt, K M et al (1979). ‘Regional lung clearance studies of excess bronchial secretions during chest physiotherapy in patients with stable chronic airways obstruction’, Lancet, 1, 294-297.
Gilmartin, J J and Gibson, G J (1986). ‘Mechanisms of paradoxical rib cage motion in patients with chronic obstructive pulmonary disease’, American Review of Respiratory Disease, 134, 683-687.
British Thoracic Society (2003). ‘British guideline on the management of asthma’, Thorax, 58 (suppl 1), 1-83.
Goldman, M and Mead, J (1973). ‘Mechanical interaction between diaphragm and rib cage’, Journal of Applied Physiology, 35, 197-204.
Campbell, A H, O’Connell, J M and Wilson, F (1975). ‘The effect of chest physiotherapy upon FEV1 in chronic bronchitis’, Medical Journal of Australia, 1, 33-35.
Hondras, M A, Linde, K and Jones, A P (2000). ‘Manual therapy for asthma (Cochrane Review)’ Cochrane Library, issue 4, Update Software, Oxford.
Celli, B (1986). ‘Respiratory muscle function’, Clinical Journal of Chest Medicine, 7, 567-580.
Kakizaki, F, Shibuya, M, Yamazaki, T et al (1999). ‘Preliminary report on the effects of
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respiratory muscle stretch gymnastics on chest wall mobility in patients with chronic obstructive pulmonary disease’, Respiratory Care Medicine, 44, 409-414.
Pryor, J A and Webber, B A (1979). ‘An evaluation of the forced expiration technique as an adjunct to postural drainage’, Physiotherapy, 65, 304-307.
National Institute of Health (1977). Guidelines for the Diagnosis and Management of Asthma 1997). NIH, Bethesda, USA. Publication 99 – 4051.
Zudaire, L E, Del Rio, M T, Bermejo, T B and Cuartero, B G (2000). ‘Status asthmaticus: Is respiratory physiotherapy necessary?’ Allergology et Immunopathology, 28, 290-291.
Orlandi, O, Perino, B and Testi, R (1989). ‘Old and new in chest physiotherapy’, European Respiratory Journal, suppl 7, 595-598.
Key Messages ■ Chest physiotherapy manoeuvres such as postural drainage, vibratoryshaking and huffing are safe in people with stable asthma. ■ There is no significant difference in FEV1 or peak expiratory flow rate induced by chest physiotherapy in people with stable asthma.
■ Clinical trials with chest physiotherapy must be performed in order to establish the safety and effectiveness of chest physiotherapy in episodes of asthma exacerbation. ■ Most people with stable asthma feel unchanged or even improved after chest physiotherapy.
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Key Words Asthma, chest physiotherapy, airway secretion, pulmonary function tests.
Chest Physiotherapy Does Not Induce Bronchospasm in Stable Asthma
by Viviani Barnabé Beatriz Saraiva Rafael Stelmach Milton A Martins Maria do Patrocínio T Nunes
Study objectives A recent systematic review concluded that it is not possible to judge manual chest physiotherapy safety in asthma. This study measured the effects of chest physiotherapy on pulmonary function and symptoms and safety in people with stable asthma. Design Prospective controlled study. Setting University general hospital. Patients Eighty-one asthma patients attending an asthma clinic with stable asthma, 62 adults and 19 children, and 15 adults without asthma recruited from members of staff of the hospital. Interventions Spirometry was performed before and five minutes after chest physiotherapy, which included postural drainage, percussion, vibratory-shaking and the forced expiration technique – ‘huffing’. Measurements and results There were no significant changes in FEV1 and FEF25-75% induced by chest physiotherapy in adults with mild and moderate or severe asthma and in children with mild and moderate asthma. After chest physiotherapy there was no decrease in FEV1 greater than 20%. Of the children 32% and of the adults 4% complained of worsening in asthma symptoms after physiotherapy manoeuvres. However, FEV1 did not decrease more than 10% in any of them. Eight hours after treatment, participants with moderate asthma did not show a significant change in FEV1. Conclusions Chest physiotherapy manoeuvres, including postural drainage, percussion, vibratory-shaking and ‘huffing’, do not induce a significant worsening in airway obstruction in subjects with stable asthma, including patients with severe asthma.
Barnabé, V, Saraiva, B, Stelmach, R, Martins, M A and Nunes, M do P T (2003). ‘Chest physiotherapy does not induce bronchospasm in stable asthma’, Physiotherapy, 89, 12, 714-719. Physiotherapy December 2003/vol 89/no 12
Introduction Chest physiotherapy is effective in enhancing the clearance of tracheobronchial secretions and helping in the promotion of pulmonary rehabilitation in several pulmonary diseases (Barnes, 1994). Chest physiotherapy usually includes various combinations of postural drainage, percussion, vibratory-shaking, breathing exercises, directed coughing and the forced expiration technique (‘huffing’). Chest physiotherapy has been indicated in patients with mucus hypersecretion, with the exception of asthma, where it has been reported to induce bronchospasm (Barnes, 1994). However there is a dearth of literature in this area, particularly with relevance to acute asthma. In an exacerbation of asthma as a result of factors such as viral or bacterial infection, allergen exposure and climate changes, bronchospasm, vasodilatation with peribronchiolar and perivascular oedema and mucus hypersecretion occur (NIH, 1997). However, the role of chest physiotherapy in these circumstances remains unclear (Zudaire et al, 2000). Chest physiotherapy in various forms is thought to be of some benefit in asthma, possibly through airway secretion mobilisation and thoracic muscular relaxation (Orlandi et al, 1989; Eid et al, 1991). However, Hondras et al (2000) and Ernst (2000), in a recent systematic review of manual therapy for asthma, concluded that ‘currently there is insufficient evidence to support or to refute the use of manual therapy for patients with asthma’. It has been considered that in status asthmaticus the increased stimulation induced by chest physiotherapy may worsen a patient's unstable condition, as a consequence of bronchial hyperresponsiveness (Barnes, 1994). In addition, it has been observed that percussion
Research report
may induce bronchospasm in chronic pulmonary diseases (Campbell et al, 1975; Feldman et al, 1979). However, there are many chest physiotherapy manoeuvres that have not been evaluated extensively in asthmatic patients (Hondras et al, 2000; Asher et al, 1990). Chest percussion, shaking, vibration and postural drainage have been postulated as increasing the mobilisation of bronchial secretions to more central airways for expectoration by coughing (Eid et al, 1991). Since these procedures have not been studied before in asthmatic patients, it is necessary to assess the safety of these manoeuvres, initially in clinically stable patients. The purpose of the present study was to evaluate pulmonary function and symptoms before and after chest physiotherapy, in people with stable asthma, in order to study the potential bronchospastic effects of these manoeuvres. Patients and Methods The protocol was approved by the institutional Ethics Review Committee. Each of the subjects, or the parents in the case of children, gave written informed consent. Study Population Sixty-two stable adult asthmatic patients and 19 asthmatic children entered the study. These subjects were recruited from patients attending the Asthma Centre of the Clinics Hospital of the University of São Paulo. They were classified as having mild, moderate or severe asthma, according to National Institute of Health criteria (NIH, 1997). They were included in the study if they were considered stable by their physicians and had not had any asthma exacerbation in the previous four weeks. Fifteen non-asthmatic subjects followed the same protocol of chest physiotherapy and served as controls. They were recruited from staff members of the Asthma Centre. Abbreviations
FEV1 - forced expiratory volume in the first second of forced vital capacity FEF25-75% - forced expiratory flow at 25-75% of vital capacity
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Four groups were studied: ■ A control group of adults without asthma (n = 15). ■ Adults with mild and moderate stable asthma (n = 50). ■ Children with mild and moderate asthma (age 6-12 years, n = 19). ■ Adults with severe asthma (n = 12). Measurement of Pulmonary Indices Spirometry was performed on all subjects according to American Thoracic Society guidelines (1995), using a spirometer (Koko, PDS Instrumentation Inc, Louisville, CO) before and five minutes after chest physiotherapy. Peak expiratory flow rate was also measured with a peak flow meter (Mini-Wright, Clement Clark International, Essex). Study Design Bronchodilators were suspended six hours before measurement. All subjects had baseline spirometric measurements taken. Patients completed a short questionnaire in which they were asked if they were currently experiencing symptoms of asthma including respiratory distress, cough or chest tightness. Subsequently each subject under went a non-stop 15-minute period of chest physiotherapy: ■ For the first 14 minutes the patients were seated in a position where the thorax was inclined forwards by 45˚ (position of postural drainage for the posterior segment of the superior lobe) where percussion and vibratoryshaking were performed. ■ Subsequently they were seated upright against the backrest of the chair (position of postural drainage for the apical segment of the superior lobe) where percussion and vibratoryshaking were performed. ■ Finally, still seated but with the thorax inclined backwards by 45˚ (position of postural drainage for the anterior segment of the superior lobe) the same manoeuvres were repeated. In the last minute the forced expiration technique was undertaken. ■ Five minutes after manual therapy, patients were asked if their asthma symptoms – respiratory distress, cough and/or chest tightness – were better, worse or unchanged, and further spirometric measurements were taken.
Authors Viviane Barnabé MSc is a physiotherapist instructor in the School of Physiotherapy, UNICID, São Paulo, Brazil. Beatriz Saraiva MSc is a research associate and Maria do Patrocínio T Nunes MD PhD is assistant professor in the School of Medicine, University of São Paulo, Brazil. Rafael Stelmach MD is a staff physician in the Division of Pulmonary Diseases and Milton A Martins MD PhD is a professor of medicine and director of the Division of General Internal Medicine, at the Clinics Hospital, University of São Paulo, Brazil. Authors’ Contribution Viviane Barnabé participated in experimental design, data collection and analysis and writing of the manuscript. Beatriz Saraiva participated in data collection and analysis and reviewed the final manuscript. Rafael Stelmach participated in experimental design and reviewed the final manuscript. Milton A Martins participated in experimental design, data analysis and writing of the manuscript. Maria do Patrocínio T Nunes participated in experimental design, data collection and analysis and writing of the manuscript.
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Eight hours later, peak expiratory flow rate was recorded in adults with mild and moderate asthma (n = 50) to evaluate the potential late effects of physiotherapy on lung function. People in this group had not used bronchodilators in the six hours before chest physiotherapy, to avoid confounding effects on peak expiratory flow rate. Statistical Analysis Comparisons of pulmonary function tests before and after chest physiotherapy were performed using paired Student’s t-test. A one-way repeated measures analysis of variance was used to study the peak expiratory flow rate values obtained before, immediately after and eight hours after chest physiotherapy. Frequency analysis was used to evaluate the possible categories of answer for clinical symptoms in the four groups. The results are expressed as means ± standard error. Statistical analysis was performed using SigmaStat 2.1 software (Jandel Corp, San Rafael, CA). A value of p < 0.05 was considered significant. Results Table 1 shows demographic data of the four groups studied. All subjects completed the study. No decrease in FEV1 of more than 20% of control values was noted in any subject during the study. In fact, only two children and seven adults demonstrated a decrease in FEV1 greater than 10% (110 to 280 ml for adults). Table 1: Clinical characteristics and demographic data of studied subjects Subjects
N Age (mean ± SEM) (mean ± SEM)
Non-asthmatic subjects
15
Years of asthma
24.2 ± 2.1
Mild and moderate asthma
50
24.9 ± 2.3
15.0 ± 2.2
Severe asthma
12
40.5 ± 17.7
18.9 ± 10.3
Mild and moderate asthmatic children 19
9.7 ± 2.5
7.6 ± 3.2
Table 2: Percentage of answers related to chest symptoms after chest physiotherapy Subjects
Worse
Unchanged Better
Non-asthmatic subjects (n = 15)
0
47
Mild and moderate asthma (n = 50)
4
53
42
Severe asthma (n = 12)
0
36
64
Mild and moderate asthmatic children (n = 19) 32
21
47
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Figure 1 shows the mean values of forced expiratory volume in one second (FEV 1 , percent predicted) before and five minutes after chest physiotherapy in the four groups studied. There was no significant change in FEV 1 induced by chest physiotherapy in the four groups studied, although a trend was observed for higher values of FEV 1 after chest physiotherapy in the control group, in the group of adults with severe asthma, and in asthmatic children. Figure 2 shows forced expiratory flow at 25-75% of vital capacity (FEF25-75). Higher values of FEF25-75 after chest physiotherapy were observed in the control group, children with asthma and severe asthmatics, but these differences were not statistically significant. Figure 3 shows values of patients’ peak expiratory flow with mild or moderate asthma measured before, five minutes after and eight hours after chest physiotherapy. There was no significant change in peak expiratory flow values induced by chest physiotherapy. Additionally, peak expiratory flow rate did not decrease by more than 20% of the baseline values. Chest physiotherapy was well tolerated by patients with asthma. Only two adults and six children with asthma reported worsening in symptoms after chest physiotherapy (table 2). However, the asthmatics who complained of worsening in symptoms demonstrated a decrease in FEV 1 no greater than 10% when compared with their baseline values. Discussion In this study, chest physiotherapy was well tolerated by people with stable asthma. The majority of patients reported feeling unchanged or even improved immediately after chest physiotherapy (table 2). More importantly, even patients with severe asthma demonstrated no significant decrease in FEV 1 or peak expiratory flow rate induced by chest physiotherapy. Only two adults (4.3%) reported worsening of symptoms. The percentage of children who complained of worsening in symptoms was higher (31.5%). However, none of these children demonstrated a decrease in FEV1. Since they were not used to chest physiotherapy, it is possible that some of their symptoms were due to discomfort induced by the manoeuvres used. Asthma has been described as a possible
Research report
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Key to all figures Before chest physiotherapy
FEV1 (% predicted)
contra-indication to chest physiotherapy along with critical illness, spinal cord trauma and intra-cranial hypertension (Orlandi et al, 1989). Few previous studies of asthmatic patients involve chest physiotherapy (Pryor and Webber, 1979). Based on such data, Ernst (2000) concluded that it is not possible to judge the effects of chest physiotherapy in asthma. According to the Guideline for the Management of Asthma of the British Thoracic Society (2003), since the number of studies is very small, it is not possible to make an evidence-based recommendation about breathing exercises for asthma. To our knowledge, no previous studies have been reported which evaluated whether chest physiotherapy manoeuvres, such as postural drainage, percussion, vibratoryshaking and the forced expiration technique (‘huffing’), resulted in airway obstruction in stable asthmatics. The manoeuvres utilised in the present study have been used to assist removal of excess tracheobronchial secretions in patients with various pulmonary diseases (Orlandi et al, 1989; Eid et al, 1991). Our results suggest that these manoeuvres are safe for patients with stable asthma. However, this study was not designed to evaluate the effectiveness of chest physiotherapy in asthma, but merely the safety of such manoeuvres in this kind of patient. Another limitation of this study was that only stable asthmatics were evaluated. It is possible that the effects of these manoeuvres could be more intense in people with unstable asthma, where the amount of mucus produced in the airways is greater. However, the safety of these procedures has yet to be demonstrated in people with unstable asthma. Because of the potential for chest physiotherapy to provoke bronchospasm, these techniques are not usually indicated in emergency rooms or intensive care units for unstable, mucus producing asthmatic patients (Barnes, 1994; Campbell et al, 1975; Feldman et al, 1979). In addition, Zudaire
80
60
40
20
Control group
Mild/moderate asthma
Severe asthma
Children with asthma
Fig 1: Mean FEV1 before and after chest physiotherapy. There were no significant differences in FEV1 values induced by chest physiotherapy in the four groups studied. Bars indicate standard errors
100 FEV25-75% (% predicted)
8 hours after chest physiotherapy
80
60
40
20
Control group
Mild/moderate asthma
Severe asthma
Children with asthma
Fig 2: Mean FEF25%-75% before and after chest physiotherapy. There were no significant differences in FEF25%-75% values before and after chest physiotherapy in the four groups studied. Bars indicate standard errors 600
500 Peak expiratory flow (L/min)
5 minutes after chest physiotherapy
100
400
300
200
100
Mild and moderate asthmatics
Fig 3: Mean values of peak expiratory flow rate for patients with mild or moderate asthma, measured before and after chest physiotherapy. There were no significant differences in peak expiratory flow rate values before, immediately after and eight hours after chest physiotherapy. Bars indicate standard errors
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Address for Correspondence Maria do Patrocínio T Nunes MD, Faculdade de Medicina da Universidade de São Paulo, Av Dr Arnaldo, 455 sala 1216, 01246-903 – São Paulo – SP, Brazil. E-mail [email protected] Presentation This study was presented in part at the meeting of the European Respiratory Society in Geneva, Switzerland, in 1998. Acknowledgements We would like to thank the physicians, physiotherapists, nurses, biologists and secretaries of the Asthma Centre of the Hospital das Clínicas of the University of Sao Paulo for their help in this study.
et al (2000) reported the appearance of a pneumothorax immediately after chest physiotherapy in a four-year-old girl with status asthmaticus, suggesting that caution should be exercised. It is also possible that due to the small size of three of the subject groups the power of the analysis may have been insufficient to detect a difference, even if one had been present. However, the similarities in the responses of all four groups suggests that some confidence can be placed in these trends. The overall power in the analysis of variance was 80%. We observed that chest physiotherapy did not induce or worsen bronchospasm in healthy subjects or stable asthmatic patients. In contrast, an enhancement in pulmonary function was observed in some subjects. An improvement in pulmonary function could be explained as the result of thoracic muscular relaxation, a possible increase in airway secretion mobilisation and also possibly some learning effects (Eid et al, 1991; Barnes, 1994). Thoracic muscular contraction is, at least partially, due to the inadequate use of the diaphragm muscle in asthma. This weak performance results in overuse of the accessory respiratory muscles
(Goldman and Mead, 1973; Celli, 1986). Thoracic muscular relaxation results in better pulmonary mechanics and in a decrease of respiratory load (Gilmartin and Gibson, 1986; Kakizaki et al, 1999). Air way secretion mobilisation, as a consequence of thoracic percussion, is thought to facilitate airflow in the airways, which in turn results in better pulmonary ventilation (Bateman et al, 1979). An improvement of respiratory symptoms as described by 43% to 64% of asthmatic patients after chest physiotherapy was observed. This finding could be explained by the occurrence of chest wall muscle relaxation secondary to the physiotherapy manoeuvres. Conclusion Our results suggest that chest physiotherapy manoeuvres such as postural drainage, percussion, vibratory-shaking and the forced expiration technique (‘huffing’) are safe in people with stable asthma, including those with severe asthma. Clinical trials with chest physiotherapy in episodes of asthma exacerbation must be conducted in order to establish safety and effectiveness in the wider asthmatic population.
References Funding This study was supported by the following Brazilian Scientific Agencies: Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) and Programa de Núcleos de Excelência (PRONEX-MCT).
American Thoracic Society (1995). ‘Standardisation of spirometry: 1994 update’, American Journal of Respiratory Critical Care Medicine, 152, 1107-36. Asher, M I, Douglas, C, Airy, M et al (1990). ‘Effects of chest physical therapy on lung function in children recovering from acute severe asthma’, Pediatric Pulmonology, 9, 146-151.
Eid, N, Buchheit, J, Neuling, M et al (1991). ‘Chest physiotherapy in review’, Respiratory Care Medicine, 36, 270-282. Ernst, E (2000). ‘Breathing techniques: Adjunctive treatment modalities for asthma: A systematic review’, European Respiratory Journal, 15, 969-972.
Barnes, T A (1994). Core Textbook of Respiratory Care Practice, Mosby Yearbook, Missouri, 2nd edn, 203-240.
Feldman, J, Traver, G A and Tanssig, C M (1979). ‘Maximum expiratory flows after postural drainage’, American Review of Respiratory Disease, 119, 239-245.
Bateman, J R M, Newman, S P, Daunt, K M et al (1979). ‘Regional lung clearance studies of excess bronchial secretions during chest physiotherapy in patients with stable chronic airways obstruction’, Lancet, 1, 294-297.
Gilmartin, J J and Gibson, G J (1986). ‘Mechanisms of paradoxical rib cage motion in patients with chronic obstructive pulmonary disease’, American Review of Respiratory Disease, 134, 683-687.
British Thoracic Society (2003). ‘British guideline on the management of asthma’, Thorax, 58 (suppl 1), 1-83.
Goldman, M and Mead, J (1973). ‘Mechanical interaction between diaphragm and rib cage’, Journal of Applied Physiology, 35, 197-204.
Campbell, A H, O’Connell, J M and Wilson, F (1975). ‘The effect of chest physiotherapy upon FEV1 in chronic bronchitis’, Medical Journal of Australia, 1, 33-35.
Hondras, M A, Linde, K and Jones, A P (2000). ‘Manual therapy for asthma (Cochrane Review)’ Cochrane Library, issue 4, Update Software, Oxford.
Celli, B (1986). ‘Respiratory muscle function’, Clinical Journal of Chest Medicine, 7, 567-580.
Kakizaki, F, Shibuya, M, Yamazaki, T et al (1999). ‘Preliminary report on the effects of
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respiratory muscle stretch gymnastics on chest wall mobility in patients with chronic obstructive pulmonary disease’, Respiratory Care Medicine, 44, 409-414.
Pryor, J A and Webber, B A (1979). ‘An evaluation of the forced expiration technique as an adjunct to postural drainage’, Physiotherapy, 65, 304-307.
National Institute of Health (1977). Guidelines for the Diagnosis and Management of Asthma 1997). NIH, Bethesda, USA. Publication 99 – 4051.
Zudaire, L E, Del Rio, M T, Bermejo, T B and Cuartero, B G (2000). ‘Status asthmaticus: Is respiratory physiotherapy necessary?’ Allergology et Immunopathology, 28, 290-291.
Orlandi, O, Perino, B and Testi, R (1989). ‘Old and new in chest physiotherapy’, European Respiratory Journal, suppl 7, 595-598.
Key Messages ■ Chest physiotherapy manoeuvres such as postural drainage, vibratoryshaking and huffing are safe in people with stable asthma. ■ There is no significant difference in FEV1 or peak expiratory flow rate induced by chest physiotherapy in people with stable asthma.
■ Clinical trials with chest physiotherapy must be performed in order to establish the safety and effectiveness of chest physiotherapy in episodes of asthma exacerbation. ■ Most people with stable asthma feel unchanged or even improved after chest physiotherapy.
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