What is the difference in the lungs of an athlete and a clerk.

Transcription

1 48 SUPPLEMENT TO JAPI FEBRUARY 2012 VOL. 60 Pulmonary Rehabilitation in COPD Sheetu Singh *, Virendra Singh ** Introduction What is the difference in the lungs of an athlete and a clerk. Lungs of both of them are normal. Athlete has trained his lungs and body to perform rigorous exercise and able to run 20 kilometre (km) in one stretch while the clerk working in an office is hardly able run for 2 km. Even in normal lungs training and exercise result in a ten fold improvement in performance. Similarly a patient with chronic obstructive airway disease (COPD) who is unable to walk 100metres can be trained under the pulmonary rehabilitation programme to walk greater distances and perform tasks which he could not do previously. Exercise training and rehabilitation have been shown to reduce disability in many chronic respiratory diseases. 1,2 COPD is progressive disease 3 with poor prognosis. In severe cases patients treatment options are limited and oxygen is the only modality that prolongs survival. 4 With disease advancement, co-morbidities and recurrent exacerbations a patient becomes disabled. Disability is a cause of decreased activity, social isolation and depression. Further, decreased activity is an independent predictor of mortality in COPD 5. The aim of pulmonary rehabilitation is to break this vicious cycle and help the COPD patients to participate in daily activities. It is known to improve quality of life and exercise tolerance in COPD. 6 Why COPD Patient Develop Dyspnoea? Dyspnoea and exercise intolerance in COPD are due to multiple factors. Expiratory airflow obstruction 7 is an important cause but not the only one. Inspiratory muscle dysfunction, 8 gas exchange abnormalities 9 and cardiac dysfunction 10 are other causes. Exercise intolerance can be best explained by the concept of dynamic hyperinflation 11. The motion of thorax is restricted due to hyperinflation and thereby capacity to increase tidal volume during exercise is limited. Hyperinflation also compromises the ability of inspiratory muscles to generate pressure 12 and weakens them. Pulmonary Rehabilitation American thoracic society and European respiratory society proposed the most acceptable definition in It states Table 1 : Methods of pulmonary rehabilitation 1. Smoking cessation 2. Clearing of airway secretions 3. Breathing techniques 4. Exercises 5. Energy conservation and fatigue obviation 6. Rehabilitation in exacerbations 7. Patient education 8. Future research * Chest Consultant, Asthma Bhawan, Jaipur; ** Professor and Head, Division of Allergy and Pulmonary Medicine, SMS Medical College, Jaipur Pulmonary rehabilitation is an evidence-based, multidisciplinary, and comprehensive intervention for patients with chronic respiratory diseases who are symptomatic and often have decreased daily life activities. Integrated into the individualized treatment of the patient, pulmonary rehabilitation is designed to reduce symptoms, optimize functional status, increase participation, and reduce health care costs through stabilizing or reversing systemic manifestations of the disease. 9 A lot of research has been done in various aspects of pulmonary rehabilitation in patients with COPD. This review analyzes the methods of pulmonary rehabilitation and various aspects as follows (Table 1). 1. Smoking cessation With age lung functions decline and usually forced expiratory volume one second (FEV1) declines 20 ml every year after 20 years of age. In smokers annual decline in FEV 1 is 35 to 40 ml. None of the existing medicines can reduce the faster rate of decline in lung functions in a smoker. Only strategy to prevent faster rate of decline is cessation of smoking. It has been observed that in former smokers annual decline in FEV 1 is around 20 ml per year. These observations emphasise the need of counselling smokers to quit at the time of every consultation. 2. Clearing of secretions Cough and sputum production are key symptoms of COPD. Traditional definition of chronic bronchitis is also based on chronic production of sputum. Presence of secretions in airways not only interferes in ventilation but also in physical capacity. Therefore clearing of airways from secretions is an important step before performing exercises. Good hydration, smoking cessation, avoidance of irritants and bronchodilator therapy are prerequisites. Chest physiotherapy is helpful in clearing secretions and subsequently preventing sequelae like dyspnoea and hypoxemia. Controlled cough and forced expiration are two techniques found useful 13. Patients with severe COPD may tolerate the latter technique better. The techniques should be practised every morning ten minutes after the dose of short acting bronchodilator. They may be practised more frequently in patients with problem of copious sputum. Postural drainage is practised in patients with localised disease. Gravity helps in drainage of secretions. A combination of chest physiotherapy and postural drainage may provide adequate clearance of secretions, but has no effect on lung functions. Mucolytics have doubtful role in management of cough sputum in a COPD patient. Cough suppressants that depress the cough centre should be used with caution because these may also cause respiratory depression. 3. Breathing techniques Some breathing techniques are useful in providing relief in dyspnoea in patients with severe COPD. The patient is advised to breathe slowly and deeply to reduce dead space and improve carbon dioxide elimination. This pattern of breathing reduces physiological dead space, improves carbon dioxide removal and consequently ventilation.

2 SUPPLEMENT TO JAPI FEBRUARY 2012 VOL Fig. 1 : Pursed lip breathing Pursed lip breathing (Figure 1) is assumed by some COPD patients instinctively during an exacerbation. It is a pulmonary rehabilitation approach employed to relieve patient of dyspnoea. Pursed lip breathing involves active expiration against resistance. 14 Resistance may be provided at level of lips or tongue and a whistling is produced during expiration. 15 It is called as pursed lip breathing. When resistance imposed at level of vocal cords it is called as grunting. This procedure reduces the respiratory rate and improves tidal volume. 16 Other theories to explain improvement in ventilation with pursed lip breathing are alteration in respiratory muscle recruitment 17 and development of positive pressure in the airways during breathing, thereby preventing dynamic airway collapse. 18 Diaphragmatic breathing (Figure 2) is another pattern of breathing which distracts the patient from the distress of dyspnoea and alleviates the anxiety. 19 This form of breathing is practised when patient is comparatively less distressed. One hand is kept on the chest and another on the abdomen. Patient is instructed to take abdominal breathing by taking a deep slow inspiration and allow the abdominal wall to move outward. The possible mechanism of action of this method is altered respiratory muscle recruitment and reduction in respiratory frequency Exercises Exercise improves vigour, health status 13 and life expectancy 21 in normal healthy individuals. The role of exercise in COPD as a treatment modality was introduced around twenty years before. A number of studies and meta-analysis have been performed to decide the indications, intensity, duration and long term effects of exercise. It has been observed that around 30% of muscle mass gets wasted in an average COPD patient. 22 Poor muscle mass leads to early fatigue and decreased exercise tolerance. Muscle wasting is also an indicator of poor survival. Exercise training replaces type II muscle fibres (fast, fatigable, low oxidative) with type I fibres (slow, fatigue-resistant, high oxidative). 23 Thus, exercise training builds up muscle mass and strength. It has been known to increase exercise capacity, improve health related quality of life measures and Fig. 2 : Diaphragmatic breathing: During inspiration diaphragm descends down and abdomen moves out. Patient exhales through nose with abdomen drawing in reduces symptoms of dyspnoea. Exercise also has psychosocial benefits with reduced prevalence of depression. 24 However, there is inadequate evidence that indicate improvement in survival in COPD patients. a. Type of exercises The muscle strength and endurance are increased for the specific group of muscle trained. Thus, both upper limb and lower limb exercise training are advised 24. Lower limb training includes treadmill, cycle ergometry and corridor walking 9. Various studies have reported an increase in peak exercise capacity, walking distance and endurance 25. Many COPD patients have difficulty in performing activities involving use of upper limbs. Upper extremity training is required in these cases and it includes ergometry, throwing and weights 9. Unsupported weights have been found superior to supported exercises in form of ergometry. Similar to lower limb muscle training arm endurance and strength are increased by upper limb muscle training. b. Who should undertake exercises of pulmonary rehabilitation? Usually patient of COPD with severe dyspnoea interfering with lifestyle, reduced tolerance to exercise and patients in pre-operative period are suitable candidates for a rehabilitation program. Some guidelines refer patients with medical research council (MRC) dyspnoea scale of more that III-IV. 24 However, one study observed benefit in COPD patients of any GOLD stage by pulmonary rehabilitation. 26 Patients with recent myocardial infarction (past three months), unstable angina, uncontrolled blood pressure, debilitating arthritis, congestive heart failure, dementia, neurological and peripheral vascular disease are not prescribed pulmonary rehabilitation. 27 c. Intensity and duration of exercise Depending on the underlying COPD, co-morbidities and muscle wasting patients are assigned either high or moderate intensities of exercises. High intensities of exercise include training at % of maximum exercise capacity 27 or heart rate. Alternatively a Borg

3 50 SUPPLEMENT TO JAPI FEBRUARY 2012 VOL. 60 scale index of dyspnoea of more than or presence of blood lactate may be taken as indicators of intensity of the exercise. 28 Performing high intensity exercise for short interval increases the strength of the muscles and performing less intense exercise for a longer interval increases the endurance. Moderate intensity of exercise includes training at 60-80% of maximum exercise capacity. 27 Training programmes of longer duration have been known to produce more benefits as compared to shorter duration programmes. Outpatient training sessions of at least three sessions per week (out of which at least two should be supervised) are followed. Minimum of 6-7 week duration of programme is followed. Training of less than 6 weeks duration is of less benefit. 29 d. Outcome measures The outcome can be measured by subjective and objective methods. Since most patients are referred for pulmonary rehabilitation due to decreased exercise tolerance, poor quality of life and increased dyspnoea, the assessment of outcome by the patient is important. Subjective methods include symptom improvement in terms of questionnaires like chronic respiratory disease questionnaire 30 and St George s respiratory questionnaire. 31 Borg scale 32 and visual analogue scale 33 can also be used to assess the degree of breathlessness. Objective methods include cardiopulmonary exercise testing (CPET), six minute walk test (6MWT), 34 incremental shuttle walk test (ISWT) and endurance shuttle walk test. 35 CPET is the gold standard as it measures maximal exercise capacity. However it is expensive and not easily available. 6MWT is a simple test and can be used to evaluate distance walked in six minutes. The results of 6MWT can be variable so alternative tests like incremental and endurance shuttle walk test have evolved. ISWT uses a 10meter long corridor in which the patient walks while increasing the speed every minute. The test is continued till the patient is fatigued. Outcome is measured in terms of total distance travelled. Endurance shuttle walk test is similar to ISWT except that the patient walks at a set pace. It is a measure of sub-maximal exercise capacity. e. Maintenance exercises The benefits of exercise programme after stopping wanes with time. Various maintenance programmes have been studied with variable results. Foglio et al 36 had studied the effect of pulmonary rehabilitation programme held yearly. They found gains similar to the standard eight week programme. Similarly other studies have found modest effects of maintenance programmes on long term results. Further research is needed to decide the duration, type and intensity of maintenance programmes. f. Adjuncts to exercise training i. Nutrition Caloric supplementation to meet increased energy requirements has to be done. Adequate carbohydrates have to be provided in COPD patients with a BMI of less than 21kg/m 2 or loss of more than 10% body weight in past six months. 9 Proteins are also required to build fat free mass. Anabolic hormones including growth hormone 37 and testosterone have also shown increase in muscle mass; however the transformation of increased muscle mass in increased exercise tolerance is uncertain. ii. Oxygen therapy It has been known to improve survival in COPD patients. COPD patients already on domiciliary oxygen require it during exercise at higher flow rates. 9 Oxygen is also indicated in patients with normal oxygen saturation at rest but with exercise induced hypoxemia. Oxygen leads to increase in the exercise capacity, intensities and endurance. 38 However the long term benefits are not known. Carrying an oxygen cylinder during exercise is also cumbersome and may discourage the patient. iii. Non invasive ventilation (NIV) NIV during exercise acts by unloading of the respiratory muscles thereby reducing the work of breathing. The results of various trials are ambiguous regarding the role of NIV during exercise. However it can be recommended that NIV provides benefit in exercise tolerance in patients with advanced COPD. 38 iv. Inspiratory muscle training It is another pulmonary rehabilitation strategy with equivocal results. It is indicated in patients with inspiratory muscle weakness. 9 There are three types of inspiratory muscle training namely voluntary isocapnic hyperventilation, inspiratory threshold loading and inspiratory resistive loading. Results of various studies with the above three techniques are inconclusive with no distinct advantage of one technique over the other. v. Neuromuscular electrical stimulation (NMES) It is applied in the patients who are bed-ridden with severe peripheral muscle weakness. 9 Patients with severe muscle weakness who are deemed unfit for pulmonary rehabilitation, after NMES are able to participate in rehabilitation programmes. Correction of nutrition, electrolyte imbalance and withdrawal of high dose steroids are measures adopted to correct the primary cause. 5. Energy conservation and fatigue obviation COPD patients have impaired lung functions, co-morbidities and muscle weakness due to which they have fatigue and dyspnoea on performing routine day to day activities. To overcome the airway obstruction and structural lung changes these patients have to spend more energy on the work of breathing. The anaerobic threshold is reduced in these patients, with glycolysis occurring in the muscles sooner than that in a healthy individual thereby restricting exercise. Earlier studies have shown that leg fatigue and dyspnoea are the major limiting factors restricting exercise. 39 Difficulty in carrying out daily activities leads to withdrawal of the patient and depression. The degree of restriction of day to day activities has to be assessed and management has to be planned accordingly. Learning new behaviour

4 SUPPLEMENT TO JAPI FEBRUARY 2012 VOL strategies forms the integral component of conserving energy. Patient should manage time accordingly with proper hours of rest so that fatigue does not occur. The pace of performing activities should be slowed down with rest of about 30 minutes after every meal and proper rest during night. Similarly work should be performed in such a way that it consumes less energy. Unsupported arm movements consume more energy and should be avoided. In breathing energy is spent less during expiration than inspiration. Therefore exertional activities should be coordinated and performed during expiration. 6. Rehabilitation in exacerbations Exacerbation of COPD nullifies the gains of pulmonary rehabilitation programme by increasing dyspnoea, disabling the patient and dipping the quality of life. Patients are not able to reach the pre exacerbation levels and are therefore referred for rehabilitation. Post exacerbation rehabilitation has been found useful in improving exercise capacity. 40 However they included small number of study subjects and further trials are required. 7. Patient education Patient education also requires a multidisciplinary approach and includes information on exercise, diet, energy conservation, drugs and inhaler device technique. It starts with diagnosis, smoking cessation and extends up to end-of-life discussions. Educating the patient regarding the premonitory signs of an exacerbation may help patient in identifying the signs early and avoiding severe exacerbations. Psycho-social support is also required because of chronic and progressive nature of the disease. 8. Future direction Pulmonary rehabilitation has come a long way from an unknown entity to becoming the cornerstone of management of COPD. However it still needs to be implemented for all the COPD patients, which requires the physicians to be trained in this sub-speciality. We also do not know the proper intensity, duration and maintenance regimes of the exercise training which will be beneficial to the patient. The effect of pulmonary rehabilitation is another issue which has to be studied. Conclusion Pulmonary rehabilitation is a multidisciplinary approach which requires active participation of the patient as well as the physician. It has been known to improve exercise capacity, dyspnoea and health related quality of life index in COPD. However further research is required to establish exercise regimes which will benefit all the patients. References 1. Singh V, Wisniewski A, Britton J, Tattersfield AE. Effect of Yoga breathing exercises (Pranayama) on airway reactivity in subjects with asthma. Lancet 1990;335: Singh V. Effect of respiratory exercises on asthma: The Pink City Lung Exerciser. J Asthma 1987;24: Global initiative for chronic obstructive airway diseases. Global strategy for the diagnosis, management, and prevention of chronic obstructive pulmonary disease. Updated MCR vision Inc 2007;2. 4. Nocturnal Oxygen Therapy Trial Group. Continuous or nocturnal oxygen therapy in hypoxemic chronic obstructive lung disease: a clinical trial. Ann Intern Med 1980;93: Yohannes AM, Baldwin RC, Connolly MJ. Predictors of 1-year mortality in patients discharged from hospital following acute exacerbation of chronic obstructive pulmonary disease. Age Aging 2005;34: Singh V, Khandelwal DC, Khandelwal R, Abusaria S. Pulmonary rehabilitation in patients with chronic obstructive pulmonary disease. Indian J Chest Dis Allied Sci 2003;45: Hyatt RE. Expiratory flow limitation. J Appl Physiol 1983;55: American Thoracic Society/European Respiratory Society. Skeletal muscle dysfunction in chronic obstructive pulmonary disease: a statement of the American Thoracic Society and European Respiratory Society. Am J Respir Crit Care Med 1999;159:S1 S40 9. American thoracic society and European respiratory society. American Thoracic Society/European Respiratory Society Statement on Pulmonary Rehabilitation. Am J Respir Crit Care Med 2006;173: World Health Organization. Definition of chronic cor pulmonale. Circulation 1963;27: O Donnell DE, Revill SM, Webb KA. Dynamic hyperinflation and exercise intolerance in chronic obstructive pulmonary disease. Am J Respir Crit Care Med 2001;164: Aliverti A, Stevenson N, Dellaca RL, Lo MA, Pedotti A, Calverley PM. Regional chest wall volumes during exercise in chronic obstructive pulmonary disease. Thorax 2004;59: Blair SN. McCloy research lecture: physical activity, physical fitness and health. Res Q Exerc Sports 1993;64: Faling LJ. Pulmonary rehabilitation-physical modalities. Clin Chest Med 1986;7: Rodenstein DO, Stanescu DC. Absence of nasal airflow during pursed lip breathing: the soft palate mechanism. Am Rev Respir Dis 1983;128: Mueller R, Petty T, Fiflev G. Ventilation and arterial blood gas changes induced bı pursed-lip breathing. J Appi Physiol 1970;28: Breslin EH. The pattern of respiratory muscle recruitment during pursed lip breathing. Chest 1992;101: Ingram Ru, Schilder DP Effect ofpursed lips expiration on the pulmonary pressure-flow relationship in obstructive lung disease. Am Rev Respir Dis 1967;96: Williams IP, Smith CM, McGavin CR. Diaphragmatic breathing training and walking performance in chronic airway obstruction. Br J Dis Chest 1982;76: O Donnell DE, Webb K, McGuire M. Controlling breathlessness and cough. In: Bourbeau J, Nault D, Borycki E, editors. Chronic obstructive pulmonary disease. London: BC Decker Inc, 2002; Blair SN, Kohl HW, Barlow CE et al. Changes in physical fitness and all cause mortality. A prospective study of healthy and unhealthy men. JAMA 1995;273: Bernard S, Leblanc P, Whittom F, et al. Peripheral muscle in patients with chronic obstructive airway disease. Am J Respir Crit Care Med 1998;158: Howald H, Hoppeler H, Claasen H, et al. Influences of endurance training on the ultra structural composition of the different muscle fibre types in human. Pflugers Arch 1985;403: American college of chest physician/ American association of cardiovascular and pulmonary rehabilitation guidelines panel. Pulmonary rehabilitation. Joint ACCP/AACVPR evidence based guidelines. Chest 1997;112: Lacasse Y, Wong E, Guyatt GH, et al. Meta-analysis of respiratory rehabilitation in chronic obstructive pulmonary disease. Lancet 1996;348: Berry MJ, Rejeski WJ, Adair NE, Zaccaro D. Exercise rehabilitation and chronic obstructive pulmonary disease stage. Am J Respir Crit Care Med 1999;160:

5 52 SUPPLEMENT TO JAPI FEBRUARY 2012 VOL Maltais F, Hershfield ES, Stubbing D, et al. Exercise training in patients with COPD. In: Bourbeau J, Nault D, Borycki E, editors. Chronic obstructive pulmonary disease. London: BC Decker Inc, 2002; Casaburi R, Patessio A, Ioli F, Zanaboni S, Donner CF, Wasserman K. Reductions in exercise lactic acidosis and ventilation as a result of exercise training in patients with obstructive lung disease. Am Rev Respir Dis 1991;143: Green RH, Singh SJ, Williams J, Morgan MD. A randomised controlled trial of four weeks versus seven weeks of pulmonary rehabilitation in chronic obstructive pulmonary disease. Thorax 2001;56: Guyatt GH, Berman LB, Townsend M, Pugsley SO, Chambers LW. A measure of quality of life for clinical trials in chronic lung disease. Thorax 1987;42: Jones PW, Quirk FH, Baveystock CM, Littlejohns P. A selfcomplete measure of health status for chronic airflow limitation: the St. George s Respiratory Questionnaire. Am Rev Respir Dis 1992;145: Borg GA. Psychophysical bases of perceived exertion. Med Sci Sports Exerc 1982;14: Hayes M, Patterson D. Experimental development of the graphic rating method. Psychol Bull 1921;18: McGavin CR, Gupta SP, McHardy GJ. Twelve-minute walking test for assessing disability in chronic bronchitis. BMJ 1976;1: Singh SJ, Morgan MD, Scott S, Walters D, Hardman AE. Development of a shuttle walking test of disability in patients with chronic airways obstruction. Thorax 1992;47: Foglio K, Bianchi L, Ambrosino N. Is it really useful to repeat outpatient pulmonary rehabilitation programs in patients with chronic airway obstruction? A 2-year controlled study. Chest 2001;119: Burdet L, de Muralt B, Schutz Y, et al. Administration of growth hormone to underweight patients with chronic obstructive airway disease. A prospective, randomised, controlled study. Am J Respir Crit Care Med 1997;156: American college of chest physician/ American association of cardiovascular and pulmonary rehabilitation guidelines panel. Pulmonary Rehabilitation: Joint ACCP/AACVPR evidence based clinical practise guidelines. Chest 2007;131:4S32S. 39. Killian KJ, Leblane P, Martin DH, et al. Exercise and ventilatory, circulatory and symptom limitation in patients with chronic airflow obstruction. Am Rev Respir Dis 1992;146: Man WD, Polkey MI, Donaldson N et al. Community pulmonary rehabilitation after hospitalization for acute exacerbations of chronic obstructive airway disease: randomised controlled study. BMJ 2004;329:1209.