Effects of a physical exercises program designed to increase thoracic mobility in patients with chronic obstructive pulmonary disease

Abstracts

BACKGROUND: Chronic obstructive pulmonary disease is detrimental to lung mechanics and peripheral muscles. The physical programs developed for this condition are usually targeted to an improvement on aerobics capacity. Programs that approach specifically the changes in thoracic mobility and thoracic muscles are rare. OBJECTIVE: To assess the effects of a physical exercise program designed to increase chest wall mobility on functional and psychosocial capacity in moderate to severe chronic obstructive pulmonary disease patients. METHODS: Thirty patients with moderate to severe chronic obstructive pulmonary disease were studied. They were randomized to 2 groups: control group (CG) and treated group (TG). The CG was submitted to an educational program and the TG was submitted to an educational program plus a physical exercise program aiming to increase chest wall mobility. Variables included spirometry, thoracic mobility, quality of life, anxiety and depression levels and a six minute walk test (6MWT). RESULTS: After 2 months of training, only the TG presented improvements on chest wall mobility (from 4.20 ± 0.58 cm to 5.27 ± 0.58 cm; p = 0.05) and 6MWT (from 469.73 ± 31.99 m to 500.60 ± 27.38 m; p = 0.01). It was also observed that the TG presented improvement on the St. George's Respiratory Questionnaire (SGRQ) score, Chronic Respiratory Questionnaire (CRQ), and Beck's depression scale after 2 months of treatment. Pulmonary function did not improve either in the CG or in the TG group. CONCLUSION: Our results suggest that exercises aimed to the increasing of chest wall mobility improve thoracic mobility, quality of life, submaximal exercise capacity, and reduce dyspnea and depression symptoms in chronic obstructive pulmonary disease patients.

COPD; Thoracic mobility; Quality of life; Capacity of exercise; Dyspnea

INTRODUÇÃO: A doença pulmonar obstrutiva crônica acarreta prejuízos na mecânica pulmonar e musculatura periférica. O treinamento físico dos pacientes com doença pulmonar obstrutiva crônica é geralmente voltado à melhora das condições aeróbias e são raros os programas que abordam especificamente as alterações da caixa e musculatura torácicas. OBJETIVO: Avaliar o efeito de um programa de exercícios físicos direcionados ao aumento da mobilidade da caixa torácica sobre a capacidade funcional e psicossocial de pacientes portadores de doença pulmonar obstrutiva crônica moderada e grave. MÉTODO: Foram estudados 30 pacientes portadores de doença pulmonar obstrutiva crônica moderada e grave, divididos aleatoriamente em dois grupos: controle (GC) e tratado (GT). O GC foi submetido a um programa de educação e o GT foi submetido ao mesmo programa educacional e a um programa de exercícios físicos objetivando o aumento da mobilidade torácica. Os efeitos dos programas foram avaliados pela espirometria, mobilidade torácica, qualidade de vida, níveis de ansiedade e depressão e teste da caminhada de seis minutos (TC6). RESULTADOS: Após dois meses de treinamento, somente o GT apresentou aumento na expansibilidade torácica (de 4,20 ± 0,58cm para 5,27 ± 0,58cm; p = 0,05) e no TC6 (de 469,73 ± 31,99m para 500,60 ± 27,38m; p = 0,01). Foi observado também que o GT apresentou melhora na qualidade de vida avaliada pelo St. George's Respiratory Questionnaire (SGRQ) e Chronic Respiratory Questionnaire (CRQ), bem como nos níveis de depressão após dois meses de tratamento. Não houve melhora da função pulmonar em nenhum dos dois grupos estudados. CONCLUSÃO: Exercícios direcionados ao aumento da mobilidade da caixa torácica melhoram a expansibilidade torácica, a qualidade de vida e a capacidade submáxima de exercício, bem como reduzem a dispnéia e os níveis de depressão nos pacientes portadores de doença pulmonar obstrutiva crônica.

DPOC; Mobilidade torácica; Qualidade de vida; Capacidade de exercício; Dispnéia

ORIGINAL ARTICLE

Effects of a physical exercise program designed to increase thoracic expansion in chronic obstructive pulmonary disease patients^*

Elaine Paulin^I; Antonio Fernando Brunetto^II; Celso Ricardo Fernandes Carvalho^III

^IMaster of Experimental Physiopathology and doctoral student of Physiopathology

^IIDoctor of Physiology and Professor at the Federal University of Rio Grande do Sul (UFRS)

^IIIDoctor of Physiology

^{Correspondence}

ABSTRACT

BACKGROUND: Chronic obstructive pulmonary disease is detrimental to lung mechanics and peripheral muscles. The physical programs developed for treatment of this condition are usually targeted at improving aerobic capacity. There are few programs that specifically address changes in thoracic expansion and thoracic muscles.

OBJECTIVE: To assess the effects of a physical exercise program designed to increase thoracic expansion on the functional and psychosocial capacity of patients suffering from moderate to severe chronic obstructive pulmonary disease.

METHODS: A total of 30 patients with moderate to severe chronic obstructive pulmonary disease were studied. They were randomized into 2 groups: control and treated. Control group patients were enlisted in an educational program and the treated group patients entered the educational program plus a physical exercise program intended to increase thoracic expansion. Variables included spirometry, thoracic expansion, quality of life, anxiety, depression level and a 6-minute walk test (6MWT).

RESULTS: After 2 months, only the treated patients presented improvements on thoracic expansion (from 4.20 ± 0.58 cm to 5.27 ± 0.58 cm; p = 0.05) and 6MWT (from 469.73 ± 31.99 m to 500.60 ± 27.38 m; p = 0.01). It was also observed that the treated patients presented improvement in St. George's Respiratory Questionnaire, Chronic Respiratory Questionnaire and Beck's depression scale scores. Pulmonary function did not improve in either control or treated patients.

CONCLUSION: Our results suggest that exercises aimed at increasing thoracic expansion improve thoracic expansion, quality of life and submaximal exercise capacity, as well as reducing dyspnea and depression in chronic obstructive pulmonary disease patients.

Key words: COPD. Thoracic expansion. Quality of life. Capacity of exercise. Dyspnea.

Abbreviations used in this paper:

CRQ – Chronic Respiratory Questionnaire

FVC – Forced vital capacity

COPD – Chronic obstructive pulmonary disease

SD – Standard deviation

PEF – Peak expiratory flow

SGRQ – St. George’s Respiratory Questionnaire

6MWT – 6-minute walk test

FEV₁ – Forced expiratory volume in the first second

FEV₁/FVC – Tiffeneau index

MVV – maximal voluntary ventilation

Introduction

Chronic obstructive pulmonary disease (COPD) is detrimental to lung mechanics and to the peripheral musculature.^(1,2) Changes in lung mechanics result from bronchial obstruction, which leads to displacement of the equal pressure point in the non-cartilaginous airways, thereby favoring air entrapment. In chronic cases, this process tends to cause lung hyperinflation, which reduces physical capacity – initially at maximum exertion and later at any exertion level. This hyperinflation results in remodeling of the inspiratory muscles, especially in the diaphragm, which may become depressed or flattened, thus decreasing opposition and consequently reducing its movements.⁽³⁾ There is ample evidence that such hyperinflation results in structural adaptations of the chest wall muscles.⁽⁴⁾

The physiopathological changes seen in cases of COPD tend to become more pronounced with the progression of the disease and provoke symptoms that affect quality of life and decrease the ability of a COPD patient to carry out daily activities.⁽³⁾ This creates a vicious cycle in which the patient consciously limits daily activities in order to diminish the symptoms.⁽⁵⁾ The loss of physical capacity and independence may also be responsible the mental health problems observed in COPD patients.⁽⁶⁾ In light of the various changes resulting from this disease, lung rehabilitation programs have been developed in an attempt to reverse or minimize COPD symptoms, improve physical capacity and diminish psychological alterations.

Many authors have suggested that the exercise programs for COPD patients be aimed at improving aerobic capacity.^(7,8) The remodeling of the chest wall and surrounding musculature severely compromises respiration in COPD patients. There have been few studies assessing the specific techniques for addressing this remodeling. The participation of respiratory muscles seems to be important, since the imbalance between the forces generated by the respiratory muscles and the changes in the length of the same muscles may generate dyspnea.⁽⁹⁾ In 1999, Kakisaki et al. showed that elongation of the respiratory muscles might improve thoracic expansion and decrease dyspnea in COPD patients.⁽¹⁰⁾ In 2000, Montaldo et al. suggested the existence of thoracic mechanoreceptors, situated in the chest wall and respiratory muscles, which respond to changes in length, tension or movement and, before ventilation increases, may play an important role in creating dyspnea.⁽¹¹⁾ Therefore, greater thoracic expansion might improve the length-tension ratio of the respiratory muscles, decrease the afferent stimuli for central respiratory control and reduce dyspnea.

Objective

The objective of this study was to evaluate the effects of a program of physical exercise designed to improve thoracic expansion, exercise capacity and quality of life in patients with moderate to severe COPD.

Method

Patients

A total of 30 patients with moderate to severe COPD – diagnosed as defined by the American Thoracic Society (ATS) – were studied.⁽¹²⁾ Diagnoses had been established at least 6 months previously and all patients had been stable for the previous two months. Only patients who continued to present dyspnea and physical limitations after optimal clinical and pharmacological treatment (according to ATS guidelines) were included.⁽⁸⁾ Patients who had attendant lung diseases, cardiovascular diseases or cognition impairment (diagnosed by a physician), as well as those who could not walk, had intermittent claudication or presented other physical limitations, were excluded. We also excluded those patients who were smokers, who had participated in other rehabilitation programs within the previous 12 months or who were absent without justification from 3 consecutive sessions.

All the patients were informed of the objectives and design of the study. Those who agreed to take part signed the Informed Consent according to the guidelines of the Research Ethics Committee of the Hospital das Clínicas of the University of São Paulo School of Medicine.

Design

Patients were randomly divided into 2 groups: control (n = 15) and treated (n = 15). Due to logistical considerations, randomization was achieved in a way that coordinated the health care and didactic activities of our outpatient clinic. Therefore, the first 15 patients were assigned to the treated group and the second 15 were assigned to the control group. Patients in both groups were submitted to an educational program that provided information on the disease physiopathology, the importance of regular physical activity and the need for adherence to the prescribed medication. All patients then received an informative leaflet reinforcing the information given. Subsequently, patients in the treated group were enlisted in a 2-month program of physical exercise, whereas control group patients did not return to the clinic until 2 months later, when they reported for a final evaluation. Evaluations and re-evaluations included spirometry, thoracic flow cytometry and 6-minute walking test (6MWT), as well as assessment of dyspnea, quality of life, anxiety and depression.

Physical exercise program

The physical exercise program was designed with the objective of increasing thoracic expansion (Table 1).⁽¹³⁾ The exercise sequence was intended to present increasing difficulty and the patients were instructed to inhale through the nose before each movement and to exhale through the mouth during its performance. The exercises were repeated 3 times a week over a 2-month period for a total of 24 sessions. After 12 sessions, the program was modified. Each 45-minute session consisted of 12 different exercises with 15 repetitions each. If it became necessary to interrupt a session due to dyspnea or partial oxygen saturation (below 85%), the patient was placed in sitting position and, if required, was given oxygen. Bronchial airways were cleared whenever a patient presented secretion, as evaluated through lung auscultation or expectoration during exercise sessions. During this study, no patient was submitted to physical conditioning activities and all were given regular examinations by a physician.

Parameters studied

Spirometry: A Pneumocheck^® spirometer (Welch Allyn, Skaneateles Falls, NY, USA) was used, and all procedures were carried out according to ATS guidelines.⁽¹²⁾ The parameters evaluated were: forced vital capacity (FVC), forced expiratory volume (FEV₁), Tiffenau index (FEV₁/FVC ratio), peak expiratory flow (PEF) and maximal voluntary ventilation (MVV).

Thoracic flow cytometry: The Kakizaki et al. method was employed.⁽¹⁰⁾ Axillary, xiphoid and basal expansions were determined using a tape measure. Each measurement was obtained after maximal expiration followed by maximum inspiration and another maximal expiration. Measurements were taken twice and the mean of the two values was recorded.

Quality of life: Patients were evaluated with the Saint George’s Respiratory Questionnaire (SGRQ) and the Chronic Respiratory Questionnaire (CRQ), which are specifically designed for respiratory disease sufferers.^(14,15) The questionnaires were administered by a trained interviewer and if a patient failed to understand a question, the interviewer repeated it until the patient chose an alternative. The interviewer was blinded as to which group any given patient belonged to.

Anxiety and Depression Levels: Spielberger’s state-trait anxiety inventory and Beck & Steer depression inventory, both of which were developed to detect psychosomatic diseases, were used to evaluate mental states.⁽¹⁶⁾ These inventories were taken by a trained interviewer, who, when necessary, repeated questions until the patient chose an alternative. Spielberger’s state-trait anxiety inventory comprises 40 statements. The first 20 are statements such as "I am feeling restless" and relate to self-evaluation (idate state). The remaining 20 are used to determine emotional state (idate trace).

Walking test: Each patient was submitted to a 6-minute walking test (6MWT), conducted in a closed corridor. Each test was given twice, with a 1-hour interval between the two. During the test, the patient was instructed to walk as fast as possible for six minutes and to decrease speed or interrupt the test if experiencing dyspnea or any other limiting discomfort. Examiners gave patients verbal encouragement once per minute using standard motivational phrases intended to ensure that patients walked as fast as possible throughout the test. Heart rate, respiration and partial oxygen saturation were measured before and after each test. The test was applied by a trained investigator who didn’t have access to previous evaluations or information on the group the patient belonged to.

Statistical analysis

The initial variables obtained for each group (spirometry, thoracic flow cytometry, quality of life, anxiety and depression levels and 6MWT) were compared using unpaired student’s t test. The differences between pre-treatment and post-treatment values for each studied variable were compared using the Mann-Whitney rank sum test.

Results

Pre-treatment data regarding demographics, spirometry, quality of life (as assessed by SGRQ and CRQ), distance covered in the 6MWT and thoracic flow cytometry are presented in Table 2. In the first analysis, there were no statistically significant differences among any of the variables studied, with the exception of quality of life as assessed by the SGRQ, on which patients from the treated group scored lower.

After 2 months of treatment, none of the patients studied presented changes in respiratory function (Table 3). On the other hand, the patients from the treated group presented improvement in all aspects of quality of life (including dyspnea) as evaluated both by the CRQ (Figure 1) and the SGRQ (Figure 2). In addition, after 2 months of treatment, lower levels of depression were observed in the treated group (Table 4), whereas no change in anxiety levels was observed in either group.

Patients in the treated group presented a significant increase in the expansion of the inferior thoracic region after 2 months of treatment (from 4.20 ± 0.58 cm to 5.27 ± 0.58 cm, p= 0.05) (Figure 3). On the other hand, no significant changes in thoracic expansion were observed in the control group patients (3.5 ± 0.40 to 2.50 ± 0.45) after the same length of time. The patients from the treated group presented an improvement in submaximal exercise capacity as assessed by the 6MWT (from 469.73 ± 31.99 m to 500.60 ± 27.38 m, p = 0.01) (Figure 4). No changes were observed in exercise performance for the patients in the control group (493.80 ± 15.68 to 486.87 ± 17.22).

Discussion

The present study showed that exercises designed to improve thoracic expansion also improve chest expansion, quality of life and submaximal exercise capacity, as well as reducing dyspnea and depression, in patients with moderate to severe COPD.

The increase in thoracic expansion in our study was greater in the inferior region of the thorax, suggesting an improvement in diaphragm excursion. Kakizaki et al. showed that COPD patients presented increased expansion in the apical thoracic region.⁽¹⁰⁾ A possible explanation for this difference may be the kind of exercise used, since those described by the authors were performed with the objective of stretching accessory respiratory muscles. Despite the difference between the findings of those authors and the data obtained in our study regarding the site of the improvement, decreased dyspnea was observed in both studies. This effect has previously been described as a result of muscle and respiratory endurance training.^(7,8,19,20)

Studies of standard respiratory rehabilitation programs have shown that aerobic physical conditioning does not modify lung function.^(7,8) Consequently, the fact that lung function is not altered by pulmonary rehabilitation is broadly accepted in medical literature. Kakizaki et al. showed that FVC is increased by stretching respiratory muscles.⁽¹⁰⁾ The FVC of an individual is dependent on lung elastic recoil, chest wall elasticity and respiratory muscle fitness. Exercises designed to improve respiratory muscle stretching should have no effect on lung tissue structure. Thus, it is possible that the Kakizaki exercises modified chest wall elasticity or respiratory muscle strength. In our study, increased thoracic expansion was observed, with no change in FVC. Although we are unable to explain in detail our results obtained through analysis of thoracic expansion and lung function, we hope that future studies will be able to shed light on this apparent discrepancy.

Our results also show that patients submitted to the proposed treatment presented improvements in quality of life, as assessed by the SGRQ and the CRQ. The SGRQ is the only specific questionnaire accredited in Portuguese, and, as such, was quite helpful in our study.⁽²²⁾ The CRQ was used because it contains a dyspnea aspect. Dyspnea may be measured, using various techniques and instruments, either during intense physical exertion, during normal daily activities, or while at rest.⁽²³⁾ The evaluation of dyspnea during daily activities expresses better the patient’s perception since it evaluates their normal daily activities.⁽²⁴⁾ There are two instruments commonly used to measure dyspnea during normal daily activities: the transitional dyspnea index / baseline dyspnea index and the dyspnea aspect of the CRQ.^(23,25) Between the two, the dyspnea aspect of the CRQ is considered the better instrument because it quantifies, individually, the activities that are most likely to provoke dyspnea and because it is the least influenced by the investigator.^(24,25) Another factor that justified our use of CRQ was the fact that this is the most used questionnaire in pulmonary rehabilitation studies.^(7,8)

In the present study, we observed that, prior to the study, treated patients presented lower SGRQ quality of life scores than did control patients. We do not believe that this difference indicates that the groups were heterogeneous, since they presented similar demographic, spirometric and functional parameters, as well as similar levels of anxiety and depression and comparable CRQ quality of life scores (Table 2). We believe that it may have been dender-related, since the treated group had more women than did the control group. Women have a tendency (and, in many cases, an obligation) to support their families and perform the greater part of the domestic chores. When such women have COPD, they may feel incapable of this. However, when there is no support from within the family, they must continue to carry out their normal daily activities, therefore experiencing greater dyspnea and thus a lower quality of life. These factors, which are part of our culture, may have collectively contributed to the lower pre-treatment quality of life scores in the treated group.

The patients submitted to the 2-month program of physical exercise also presented increased submaximal exercise capacity. Goldstein et al. and Casaburi et al. showed that COPD patients submitted to an aerobic physical training presented an improvement in their capacity for exercise after 1.5- to 2-month training periods.^(26,27) Although no clinical explanation was found, it is interesting to note that 1 patient in our study presented a decrease in the distance covered in the 6MWT and a decrease in thoracic expansion after the training period. All other patients improved on the 6MWT. Although unexpected, this improvement may have been due to changes in ventilatory capacity, increased thoracic expansion and improved respiratory patterns.

Based upon the results obtained, we believe that the physical exercise program used in our study presents some advantages when compared to standard physical training. The program is simple to execute, and patients adapt to it easily. In addition, it does not require costly equipment, can be conducted in a restricted area and may be performed as a group.

Despite all the benefits obtained by our patients, we recognize that our study presented some methodological limitations. The type of methodology used to evaluate thoracic expansion and the absence of lung volume data, as well as the fact that the patients were not examined by the same physician every time, all must be taken into consideration. However, in spite of these limitations, the study presents new ideas and may be an initial step toward future investigations. The program of physical exercise designed to improve thoracic expansion improved not only thoracic expansion but also quality of life and exercise capacity, as well as reducing dyspnea and depression levels of COPD patients. This program may represent yet another valuable tool in pulmonary rehabilitation.

References

Submitted: 24/02/2003. Accepted, after revision: 06/06/ 2003.

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*

Research performed at the University of São Paulo (USP) School of Medicine - São Paulo, SP. Financial Support: Universidade Paranaense e Conselho Nacional de Pesquisa (CNPq).

Publication Dates

• Publication in this collection
  02 Mar 2004
• Date of issue
  Oct 2003

History

• Accepted
  11 June 2003
• Received
  24 Feb 2003