COMPONENTS OF PULMONARY REHABILITATION
Comprehensive pulmonary rehabilitation programs generally have the following 4 major components:
1) Exercise training
2) Education
3) Psychosocial / behavioral intervention
4) Outcome assessment
These interventions are provided by a multidisciplinary team that often includes physicians, nurses, respiratory therapists, physical therapists, occupational therapists, psychologists, and social workers.
EXERCISE TRAINING
Exercise training is the foundation of pulmonary rehabilitation.
Exercise does not alter underlying respiratory impairment, but it does ameliorate dyspnea and improve other outcome measures.
Exercise prescription emphasizes endurance training targeted at 60% of maximal workload for about 20-30 minutes, repeated 2-5 times a week. Generally, this training is well tolerated.
An interval training regimen consisting of 2-3 minutes of high-intensity training (60-80% maximal exercise capacity) alternating with equal periods of rest might be a substitute for patients who cannot tolerate sustained activity.
Dyspnea ratings during maximal graded exercise testing may offer reliable predictions of exercise intensity during training. Consequently, most pulmonary programs for the improvement of aerobic capacity use dyspnea targeting to guide training intensity.
The training specificity refers to the benefit gained only in those activities involving the specific muscle groups that are trained. Because the performance of many ADL involves the use of the arms, endurance training of the upper extremities to improve arm function is important. Supported arm exercises are prescribed with ergometry or unsupported arm exercises by lifting free weights or stretching armbands.
Because peripheral muscle weakness contributes to exercise limitation in patients with lung disease, strength training is a rational component of exercise training during pulmonary rehabilitation. Even low-intensity leg and arm muscle conditioning has led to reduced ventilatory equivalent for oxygen and carbon dioxide.
The reversibility of training effects is well known. The effects of training are maintained only as long as exercise is continued. Therefore, efforts at improving long-term adherence with exercise training at home are necessary for the long-term effectiveness of pulmonary rehabilitation.
RESPIRATORY MUSCLE TRAINING
Respiratory muscle training using adequate loads improves the strength of the inspiratory muscles in patients with chronic obstructive pulmonary disease (COPD); however, it remains unclear whether this improvement results in a decrease in symptoms, disability, and handicap.
Although improvement in inspiratory muscle strength is accompanied by decreased breathlessness and increased respiratory muscle endurance, the benefits have not been well established.
EDUCATION
Education is an integral part of comprehensive pulmonary rehabilitation programs, encouraging active participation in health care, which leads to a better understanding of the physical and psychological changes that occur with chronic illness. With education, patients can become more skilled at collaborative self-management and have improved compliance.
In small groups or on an individual basis, the following topics generally are covered:
Ø Energy conservation and work simplification
o These principles assist patients in maintaining ADL and in performing job-related tasks.
o The methods include paced breathing, optimization of body mechanics, advanced planning, prioritization of activities, and use of assisted devices.
Ø Medications and other therapies
o Education about types of medication and about the action, adverse effects, dose, and proper use of all oral and inhaled medication is an important part of a comprehensive pulmonary rehabilitation program.
o Instructions in metered-dose inhaler technique and spacer devices, as well as appropriate use of oxygen, are particularly important.
Ø End-of-life education
o Because of the progressive nature of COPD, risk of respiratory failure increases over time. Unfortunately, clinical factors that are assessable at the onset of respiratory failure caused by COPD are poor predictors of the outcome of mechanical ventilation.
o The decision to initiate life support, therefore, requires patients to determine the acceptability of life-sustaining care by combining their own personal values and life goals with their physician's uncertain estimates of a meaningful recovery.
o Education during pulmonary rehabilitation provides patients with an understanding of life-sustaining interventions and of the importance of advanced planning.
PSYCHOSOCIAL & BEHAVIORAL INTERVENTION
Anxiety, depression, difficulties in coping with chronic lung disease, and the inability to cope with illness contribute to the handicap of advanced respiratory disease.
Psychosocial and behavioral interventions in the form of regular patient education sessions or support groups focusing on specific problems are very helpful. Instructions in progressive muscle relaxation, stress reduction, and panic control may help to reduce dyspnea and anxiety.
Because of the effects of chronic respiratory disease on the family, participation of family members or friends in pulmonary rehabilitation support groups is encouraged.
Depression is often comorbid with COPD. The prevalence rate for morbid depression in patients with COPD ranges from 20-60%. The etiologies for this elevated rate include genetic predisposition, grief reaction, and the effects of COPD on the central nervous system.
Once depression develops, patients are less likely to follow treatment plans; they lose function and there is a potential for them to suffer worse outcomes in exacerbations.
Other interventions, including psychotherapy, physical rehabilitation, and improved social support, may also be effective, but additional study is needed before their effectiveness can be proven.
CHEST PHYSICAL THERAPY AND BREATHING TECHNIQUES
Controlled breathing techniques and chest physical therapy are the 2 major components of the multidisciplinary approach to the rehabilitation of patients with COPD, bronchiectasis, and cystic fibrosis. Although only smoking cessation and long-term oxygen therapy prolong life in patients with COPD, it is likely that chest physical therapy does the same for persons with cystic fibrosis and diffuse bronchiectasis.
The 3 major breathing techniques include the following:
1) Pursed-lip breathing
§ Patients exhale slowly for 4-6 seconds through pursed lips held in a whistling position. This technique relieves dyspnea by increasing expiratory airway pressure, thereby inhibiting dynamic expiratory airway collapse.
§ Patients also shift their breathing pattern from a rapid respiratory rate, which is under involuntary respiratory center control, to a slower, more controlled pattern governed by voluntary cortical function. The overall work of breathing does not change and, in fact, may increase slightly.
§ The pursed-lip breathing shifts a major portion of the inspiratory work of breathing from the diaphragm to the ribcage muscles, resting the diaphragm and reducing dyspnea.
2) Posture techniques
§ Leaning-forward postures frequently relieve dyspnea in patients with COPD by reducing respiratory effort. The shifting of abdominal contents elevates the depressed diaphragm cranially, resulting in improved performance.
§ The most benefit occurs in patients with severe hyperinflation, who have paradoxical inward movement of the upper abdomen.
3) Diaphragmatic breathing
§ Some patients may benefit from this technique. The patient is taught to employ only the diaphragm during inspiration and to maximize abdominal protrusion.
§ During expiration, the patient may contract the abdominal wall muscles to displace the diaphragm more cephalad.
§ Not all patients with COPD benefit from this technique; therefore, close clinical monitoring to ascertain efficacy is required.
Chest physical therapy, along with postural drainage, enhances mucus clearance from central and peripheral lung airways. The value of this therapy in stable patients with COPD and in acute COPD exacerbation is uncertain.
Nonetheless, for patients who produce more than 30 mL of sputum every 24 hours or who have difficulty with sputum expectoration, chest physical therapy combined with postural drainage and effective coughing techniques enhances sputum expectoration; the actual benefit, however, has not been determined.
Chest physical therapy remains an essential component of therapy for bronchiectasis and cystic fibrosis. The frequency of treatments must be individualized based on the severity of disease and on the quantity of airway secretions that must be cleared.
Standard chest physical therapy with postural drainage, cough, and the forced expiratory technique is the cornerstone of such treatment regimen. Newer modalities, such as mechanical chest percussion and mask positive airway pressure, warrant further clinical trials before they can be used routinely. Chest physiotherapy is essential for the management of atelectasis in postoperative or seriously ill patients with COPD who are hospitalized.
NUTRITIONAL ASSESSMENT
The onset of weight loss in a patient with chronic respiratory disease is a poor prognostic indicator. Approximately 50% of hospitalized patients with COPD are reported to suffer from protein and calorie malnutrition.
Progressive weight loss occurs from inadequate dietary intake, diet-induced thermogenesis, increased resting energy expenditure, and failure of normal adaptive response to undernutrition. These mechanisms lead to energy imbalance and weight loss.
Maintenance of adequate nutritional status by timely screening and appropriate management is essential. Provide patient education in weight maintenance techniques and emphasize the importance of preserving muscle mass and tissue stores.
Optimal nutritional status in pulmonary rehabilitation should help to maximize the patient's state of health, respiratory muscle function, and overall sense of well-being; it also may improve disease outcome.
Obesity, which is defined as a body weight that is 20% greater than the ideal body weight, may be detrimental to respiratory function. The large fat mass increases the work of the compromised respiratory system, particularly during weight-bearing activities. Encourage reduction of the body fat mass in this patient population.
Patient evaluation
A diet history includes an assessment of nutritional, medical, and socioeconomic factors, as well as of other pertinent details that affect adequate nutrition intake.
The calculation of percentage of ideal body weight by comparing measured body weight with a standard or group norm has traditionally been performed. This assessment does not take account of lean body mass, although serial follow-up measurements are useful.
Other approaches to estimating body composition are useful. Anthropometry can be used for assessment of lean body mass. The bioelectrical impedance analysis is easy to use, noninvasive, and relatively inexpensive.
Biochemical tests have been advocated as a marker of nutritional status; they include albumin, prealbumin, transferrin, and retinol-binding protein. However, these indicators generally are not reliable in identifying inadequate nutrition. They should not be used alone in assessing nutritional status.
NUTRITIONAL INTERVENTION
With an adequate provision of calories, the usual intervention for a malnourished patient with chronic respiratory disorder results in weight gain. A calorie intake of 1.7 times the resting energy expenditure is recommended.
Provision of adequate nitrogen to maintain body stores, replete tissue mass, and spare calories is required. Based on trials, it appears that protein supplementation of at least 1.7 g/kg of body weight per day is associated with nitrogen retention and physiologic improvement.
Nutrition counseling to address the planning and preparation of a nutritionally adequate meal plan, the adequacy of the food supply, the use of nutritional supplements, and other details is essential to the success of any intervention program.
OUTCOME ASSESSMENT
Outcome assessment is an important component of a comprehensive pulmonary rehabilitation program, being used to determine individual patient responses and to evaluate the overall effectiveness of the program.
Measurement of outcomes should be incorporated into every comprehensive pulmonary rehabilitation program.
Minimal requirements include the assessment of the following measures of the patient's recovery before and after rehabilitation:
Dyspnea
Exercise ability
Health status
Activity levels
Consideration also should be given to follow-up measurements after longer periods of time, such as 6 and/or 12 months.
MEASURES OF DISABILITY
Exercise testing
Progressive exercise testing on a stationary bicycle or treadmill is performed to a heart rate of 85% of predicted maximum.
Dyspnea during exertion can be rated using a visual analogue scale. This test is reproducible and is sensitive to improvements from pulmonary rehabilitation.
Instead of an incremental increase in work rate, endurance capacity can be measured at a constant fraction of maximal work rate.
A longer exercise time indicates greater exercise endurance and leads to a reduction in ventilatory requirements.
Walking tests
The 6-minute and 12-minute walking tests, as well as shuttle walking tests, correlate positively to peak exercise performance on graded exercise tests.
The minimal increase that is clinically meaningful in 6-minute walking distance is about 54 m
Exertion and overall dyspnea
Dyspnea is the most common symptom of individuals with chronic pulmonary disease and is frequently the major reason for seeking acute care.
Dyspnea during exercise usually is measured with a category scale, such as the Borg scale or the visual analogue scale.
The effect of dyspnea on daily activities can be measured with the Medical Research Council dyspnea questionnaire or with the dyspnea component of the chronic respiratory disease questionnaire.
The relief in dyspnea correlates with a fallen ventilatory demand during exercise, indicating a training effect
Respiratory specific functional status
Functional capacity is what the patient is capable of doing, whereas functional performance is what the patient actually does on a day-to-day basis. Functional reserve is the difference between the two of these.
Pulmonary rehabilitation improves a patient's functional reserve.
Functional status usually is measured by a questionnaire, which estimates the impact of the program on various activities.
MEASURES OF HANDICAP AND QOL
Health-related QOL
A health-related QOL instrument can assess the overall benefit of improvements in the patient's symptoms, disability, and handicap.
QOL has been described as a person's satisfaction or happiness with life in demands that the patient considers important.
QOL may be considered a balance between what is desired in life and what is achieved (although these indicators are difficult to measure).
In rehabilitation, the following instruments have been used:
General health questionnaires, such as sickness impact profile and short form
Disease-specific scales, such as the chronic respiratory disease questionnaire
The St George respiratory questionnaire
The disease-specific measures demonstrate greater sensitivity to change from baseline after rehabilitation intervention.
The cost-effectiveness of pulmonary rehabilitation is largely unknown; a Canadian study determined the cost-effectiveness of a community-based pulmonary rehabilitation program for chronic obstructive pulmonary disease (COPD). Over 1 year, pulmonary rehabilitation was associated with decreased health service use, reduced direct costs, and improved health status for patients with COPD. Thus, pulmonary rehabilitation is cost-effective for patients with a relatively high use of emergency and hospital-based services.