Definition

Pulmonary rehabilitation (PR) is a comprehensive intervention for patients who remain symptomatic with chronic respiratory disease despite standard medical treatment. Chronic diseases of the lung can be manifested in many forms. Chronic obstructive pulmonary disease (COPD) is among the most common, with an estimated prevalence of at least 8% in the United States. Idiopathic pulmonary fibrosis (IPF) is less common, although the incidence increases with older age, with patients typically presenting after the age of 60 years. PR programs are designed to optimize functional status and to reduce symptoms. A multidisciplinary health care team evaluates each patient’s unique needs, with active collaboration among the patient, family members, and health care providers. Treatment programs are then devised and consist of education, physician-prescribed exercise training, nutritional and psychological counseling, and outcomes assessment. Each program includes a spectrum of intervention strategies that address both the primary condition and the secondary impairments and conditions associated with the respiratory disease, such as peripheral muscle dysfunction, anxiety, and depression. The American Thoracic Society and the European Respiratory Society, in a joint consensus statement, have endorsed the use of PR in the management of chronic respiratory disease regardless of cause [1]. Each prescription is individually specific for PR candidates with the conditions listed in Table 149.1 who have limited exercise tolerance despite standard medical treatment. This includes frequently hospitalized patients and patients undergoing lung volume reduction surgery or lung transplantation, who require PR both before and after surgery.

Symptoms

Symptoms of patients with chronic respiratory diseases such as COPD, due to persistent airflow limitation, and IPF, a condition associated with progressive scarring of the lungs (Fig. 149.1), include dyspnea, exercise intolerance, cough, and airway congestion. Initially, symptoms may be attributed to other conditions or age itself [2,3]. Whereas COPD patients are relieved by expectorating sputum, IPF patients typically are not. Both COPD and IPF patients may also have chest pain, orthopnea, sleep disordered breathing, poor endurance, anxiety, depression, and difficulty with concentration [3–5]. Inhalation of cigarette smoke is a risk factor for both conditions [3,6]. Disease progression is variable. Fatigue and any complicating conditions can further exacerbate restrictions in activities of daily living (ADLs) and quality of life [7,8]. Late-stage chronic lung disease patients tend to be home bound.

Physical Examination

Abnormal physical findings are not usually detected early on. Auscultation in COPD may eventually reveal wheezing, hyperresonant lung sounds, prolonged expiratory phase, and rales. Chest percussion may reveal hyperresonance and hyperinflation. The chest may be barrel shaped, which is consistent with hyperinflation. Auxiliary respiratory muscle use and pursed-lip breathing are common with end-stage disease.

The most common finding in patients with IPF is inspiratory “Velcro-like” crackles heard on lung auscultation, mostly in the lower lung fields. Clubbing is found in up to 50% of patients. In advanced IPF, a loud pulmonic second heart sound and peripheral edema may be found, consistent with pulmonary hypertension or right-sided heart failure. Associated signs of arthritis and proximal muscle weakness are uncommon and may suggest interstitial lung disease occurring secondary to a collagen vascular disease.

Functional Limitations

Exercise tolerance and the ability to perform ADLs may be diminished by respiratory and skeletal muscle impairment including all limbs and the trunk [9–11]. Aerobic capacity is typically reduced with early lactate accumulation and muscle fatigue [9]. With diminished muscle strength, diminished mobility, and ADL restriction, patients become further deconditioned and dependent on others, leading to decreased social interaction, increased anxiety and depression, and being home bound [3,8]. In one study, 41% of COPD patients left the house less than once per month or never in their last year of life [12]. A cycle of diminished mobility leads to further deconditioning and, in turn, worsening exertional tolerance.

Diagnostic Studies

COPD and IPF are suspected for anyone with dyspnea, cough, or exercise intolerance. For IPF, a complete medical history with appropriate serologic tests is warranted to exclude secondary causes of pulmonary fibrosis.

Spirometry is most valuable for diagnosis of COPD and IPF. Spirometry provides quantifiable and reproducible parameters of airflow obstruction and lung restriction. The Global Initiative for Chronic Obstructive Lung Disease has established that a postbronchodilator forced expiratory volume in 1 second (FEV₁) to forced vital capacity (FVC) ratio (FEV₁/FVC) of less than 70% is required for the diagnosis of COPD to be made [3]. COPD severity is stratified by symptoms, postbronchodilator FEV₁ values, and frequency of exacerbations [3]. COPD patients demonstrate an increased total lung capacity, which is consistent with hyperinflation, and an increased residual volume/total lung capacity ratio, which suggests air trapping. IPF patients, in contrast, exhibit severe restrictive physiology with reduced FEV₁ and FVC but a normal or increased FEV₁/FVC ratio and reduced total lung capacity.

Patients with emphysema or IPF have decreased lung diffusion capacity for carbon monoxide consistent with loss of effective gas exchange. Oxyhemoglobin saturation and arterial blood gas values are usually normal at rest until the later disease stages. With exercise, hypoxemia and oxygen desaturation commonly occur.

Chest radiography in patients with advanced COPD commonly reveals evidence of hyperinflation. Other findings may include bullae and increased basilar lung markings. Computed tomography (CT) scan of the chest is not routinely used to diagnose COPD but may show evidence of emphysema and/or bullae.

Bilateral, symmetric reticular opacities, with lower lung field predominance, are usually seen in IPF. High-resolution CT (HRCT) scanning can demonstrate a reticular abnormality with a subpleural, basal predominance; honeycombing with or without bronchiectasis; and absence of findings suggestive of an alternative diagnosis, such as ground-glass opacities, nodules, or cysts [6]. When a patient presents with progressive dyspnea and dry cough without known cause and is found on HRCT to show these “typical” findings, surgical biopsy is not necessary to make the diagnosis. In most other cases, histopathologic correlation is warranted along with pulmonary function testing.

Other diagnostic studies can include testing for α₁-antitrypsin deficiency for COPD, especially if there is a family history of it. Pulse oximetry allows demonstration of worsening oxygenation with activity. Reduced oxyhemoglobin saturation is an indication for supplemental oxygen therapy. Last, echocardiography is performed when right-sided heart failure is suspected.

Treatment

Management of COPD and IPF includes a comprehensive evaluation for contributing conditions as well as pharmacologic and nonpharmacologic approaches and rehabilitation as noted in Table 149.2. Pharmacologic treatment for COPD is considered in Table 149.3; it is used to reduce dyspnea and frequency of exacerbations and to improve health-related quality of life. For treatment of COPD, short-acting β-agonists and short-acting anticholinergics are equipotent in reducing dyspnea and improving exertional tolerance. In patients with more advanced disease, long-acting bronchodilators are indicated in addition to short-acting bronchodilators [3]. Inhaled corticosteroids are indicated for severe disease or repeated exacerbations despite use of long-acting bronchodilators [3]. Systemic steroids should not be prescribed for stable COPD patients because of an unfavorable risk-benefit ratio. There is insufficient evidence to support the use of any specific pharmacologic therapy for IPF [6].

Nonpharmacologic treatments include airway secretion mobilization, vaccinations (influenza and pneumococcal pneumonia), and education on smoking cessation interventions and the importance of medical regimen adherence and inhaler use techniques. Smoking cessation reduces chronic phlegm production and decreases the rate of loss of FEV₁ compared with continued smokers. Training for proper administration of nebulizers and inhalers promotes optimal medication deposition and efficacy. Thick respiratory secretions can augment dyspnea. N-Acetylcysteine is the only mucolytic readily available in clinical practice in the United States, but there is inconclusive evidence for its efficacy [13].

Patients with advanced COPD have a prevalence of osteoporosis of 36% to 60% and should be treated for osteoporosis [3