Special Considerations for Chronic Obstructive Pulmonary Disease

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This chapter presents background, special considerations related to exercise testing, prescription, and progression for individuals with chronic obstructive pulmonary disease (COPD). The case study that follows outlines the results for an older adult woman with COPD who participated in a 12-week exercise program as part of a local hospital-based outpatient pulmonary rehabilitation (PR) program that included unsupervised exercise at home. This case study presents guidance for the design of a progressive aerobic conditioning and resistance training program with a primary goal of fully optimized exercise capacity, participation in activities of daily living (ADL), adherence to long-term fitness training and physical activity, and maximum control and adaptation to disabling symptoms for an individual with stable COPD.

Case Study 16-1

Mrs. Case Study-COPD

Mrs. Case Study-COPD is a 66-year-old woman weighing 72 kg (158.7 lb) with a height of 152 cm (60 in) (body mass index [BMI] 31.2 kg ∙ m⁻²). She has a history of moderate COPD diagnosed 8 months ago following hospitalization for acute exacerbation of COPD. She has a history of hypertension, hyperlipidemia, hypothyroidism, gastroesophageal reflux disease (GERD), mild depression, and moderate obstructive sleep apnea (OSA). All comorbidities currently undergo regular evaluation, management, and follow-up by her primary care practitioner and are treated with medication. OSA is treated with nocturnal bilevel positive airway pressure. She denies any history of acute cardiovascular disease (CVD), diabetes, or cancer. She reports she has gained 10 lb since retiring 1 year ago. She is negative for α₁-antitrypsin deficiency. Risk factors for chronic lung disease include a 60 pack-year cigarette smoking history. She quit smoking 8 months ago during hospitalization and underwent cessation support in the community. She continues to take bupropion and has weaned off nicotine patch and gum without relapse, urge for relapse, or cravings. She denies any family history of heart disease, diabetes, or cancer. Her mother and brother died of COPD in their 70s. She retired 1 year ago as a stockbroker at a local firm to spend time with her aging father. Prior to retirement, she was physically active including walking 30 minutes most days. Her primary goal for an exercise program is to improve function and symptom control and reduce risk of disease worsening, physical decline, and/or hospitalization. She is divorced and attributes a high stress level to managing her finances postretirement. She lives alone and has 12 stairs at home. She feels unsteady at times and denies any history of falls. In addition to a history of smoking, her ex-husband and family “were all heavy smokers.” She has no pets. She thinks she may be sensitive to pollen but has never undergone allergy testing. She currently reports being very short of breath when around secondhand smoke or perfume. Her respiratory medications at hospital discharge include tiotropium dry powder inhaler (DPI) 18 μg one inhalation daily, indacaterol 75 μg one inhalation daily, and albuterol metered-dose inhaler (MDI) at two inhalations every 4 hours as needed for dyspnea. She tapered off oral prednisone 2 weeks postdischarge. Other medications include hydrochlorothiazide, lisinopril, pravastatin, levothyroxine, pantoprazole, and bupropion. She has performed 12 weeks of exercise as part of outpatient PR combined with self-reported home exercise. She uses a wireless activity monitor to measure steps walked. Results from this training are presented as follows.

She was asymptomatic until 1 year ago, at which point she noticed dyspnea when walking up inclines and stairs. She attributed this to getting older and being out of shape following retirement. She notes an increase in fatigue over the past few months. She denies any history of chest discomfort or dizziness. During hospitalization, electrocardiogram (ECG) showed sinus rhythm with no ectopy. Transthoracic echo was unremarkable. Two weeks following hospital discharge, she underwent pulmonary evaluation with full pulmonary function testing and 6-minute walk test (6MWT) (Table 16.1 and Box 16.1). On her current medication, she denies dyspnea at rest and has 2–3/10 category/ratio (CR) dyspnea with walking, 6–7/10 during bending over, carrying groceries, vacuuming, house work, gardening, bathing, and dressing. Her dyspnea is 7–8/10 with stairs and inclines.

Table 16.1

Pulmonary Function Testing Results: Mrs. Case Study-COPD

	Prebronchodilator		Postbronchodilator
	Predicted	Measured	% Predicted	Measured	% Change
FVC (L)	4.41	3.32	76	75	−1
FEV_1.0 (L)	3.17	2.07	65	2.10	2
FEV_1.0/FVC	72	62		63	1

Box 16.1	Six-Minute Walk Test Results: Mrs. Case Study-COPD
A series of two 6MWTs were administered. During the initial 6MWT, Mrs. Case Study-COPD had a resting SpO₂ of 94% on room air; however, she experienced desaturation to 85% on room air after 1 minute of walking. The test was stopped and, following 20 minutes of rest, was restarted exclusively to adjust her oxygen levels. Her oxygen flow rate was titrated to a setting of 3 obtained from an intermittent oxygen delivery device; yielding an SpO₂ of 90%–91% during the 6MWT.
Following 20 minutes of rest, a 6MWT was performed to evaluate functional capacity. She walked 287 m (943 ft) using pulse flow oxygen while carrying a portable M6 oxygen tank. Testing followed ATS/ERS field test standards and protocol (1). Average speed was approximately 1.79 mph. Her resting HR was 72 bpm and peak HR was 123 bpm. SpO₂ at an oxygen setting of 3 fell to 90%. Maximum dyspnea was 6/10 Borg CR dyspnea scale.

Muscle strength was measured using one repetition maximum (1-RM) method according to accepted standards for leg press, shoulder press, leg extension, latissimus dorsi pull-down, and biceps curl exercises.

Mrs. Case Study-COPD performed the following exercise prescription/progression for 12 weeks at PR and was given a home exercise prescription based on her exercise results in the PR program. She plans to exercise at a local gym and agrees to attend PR maintenance exercise monthly.

Her PR exercise training program consisted of supervised aerobic and resistance training 2 days a week for 12 weeks. During the PR training program, oxygen saturation (SpO₂), dyspnea, heart rate (HR), and blood pressure (BP) were monitored preexercise, during, and postexercise. Aerobic exercise was performed with warm-up and cool-down periods in which exercise intensity was gradually increased and decreased over 5 minutes prior to and at the end of the endurance training period. She progressed over 12 weeks to walking 20 minutes on the treadmill at maximum speed of 2.2 mph (59 m ∙ min⁻¹) and stationary bike for 10 minutes at a dyspnea score level of 2/10 on a 10-point Borg CR scale. Exercise intensity and tolerance were evaluated and maintained using a CR dyspnea rating of 4–6/10 during exercise. Increases in aerobic exercise were initially made in duration until a total duration of all aerobic modes of 30 minutes per session was achieved, followed by incremental increase in intensity. Only one variable was increased at each time with increases followed by reassessment of SpO₂, dyspnea, HR, and BP. Resistance exercises included arm and ankle weights, sit-to-stand exercises, and wall push-ups. Wall push-ups were progressed to table push-ups after 3 weeks. Hand and leg weight training included shoulder press, lateral pull-down, biceps curl, sitting row, and leg extension with the following percentages of 1-RM intensity: week 1 at 50%, week 2 at 60%, week 3 at 70%, and weeks 4–12 at 80% (Table 16.2). Given her history of deconditioning, balance training exercises were added.

Table 16.2

Progressive Resistance Training Program for Weeks 1–12 for Mrs. Case Study-COPD

Week	Monday (% RM, Sets × Repetitions)	Friday (% RM, Sets × Repetitions)
1	Baseline 1-RM testing	50, 2 × 12 of above upper and lower extremity exercises
2	60, 2 × 10	60, 2 × 10
3	70, 2 × 8	80, 2 × 8
4^a	80, 2 × 8	80, 2 × 8
5	80, 1 × 8	1-RM testing
6–8	60, 2 × 8	70, 2 × 8
9	80, 1 × 8	80, 2 × 8
10–11	60, 2 × 8	70, 3 × 8
12	80, 1 × 8	1-RM testing

^aResistance exercises included arm and ankle weights, sit-to-stand exercises, and wall push-ups. Note that wall push-ups were progressed to table push-ups after 3 weeks. Hand and leg weight training included shoulder press, lateral pull-down, biceps curl, sitting row, and leg extension.

Table 16.2 describes the exercise program guidelines recommended for Mrs. Case Study-COPD during transition from PR to her fitness center. Her maintenance exercise was augmented by monthly “tune-up” visits at her local PR maintenance program. She continues to track daily steps using a wireless step counter and meets with her former PR classmates weekly for a 30-minute mall walk followed by coffee. At the PR maintenance 2 months following PR, dumbbell lunges were added at five repetitions, each to be used 3 nonconsecutive days per week. Ongoing adherence to exercise prescription is a significant clinical concern and requires behavior change and ongoing reevaluation to promote long-term benefits. Although this area requires further research, considerations for long-term adherence include group exercise such as PR maintenance programs, community-based exercise programs, and home exercise programs that include clinical ongoing follow-up, support, problem solving, and consideration of activity monitoring.

Description, Prevalence, and Etiology

COPD is a common, treatable, preventable, progressive disorder characterized by chronic airway inflammation and progressive airflow limitation (14). Pathological changes have an impact on airways, lung parenchyma, and pulmonary vasculature depending on the COPD subtype (e.g., chronic bronchitis and/or emphysema) (14). The World Health Organization estimates that 65 million people worldwide have moderate-to-severe COPD (39). COPD is a major cause of morbidity and mortality (14); it is now the third leading cause of death in the United States and the only major cause that is on the rise (18). A history of smoking tobacco is the most important risk factor for COPD; other less common risk factors include biomass exposure and occupational exposures. Exacerbations and comorbidities may contribute to disease impact. Common comorbidities include CVD, osteoporosis, anxiety/depression, lung cancer, infections, and diabetes mellitus (14). A clinical diagnosis of COPD should be considered in persons aged ≥40 years with dyspnea, chronic cough or sputum production, and a history of exposure to risk factors (tobacco smoke, occupational smoke, dust, chemicals, indoor air pollution, and/or family history of COPD) (14). Accurate diagnosis and assessment of severity requires spirometry and, often, full pulmonary function testing. The presence of significant expiratory airflow limitation, the hallmark of the disease, is assessed by spirometry. Forced expiratory volume in 1 second (FEV_1.0)/forced vital capacity (FVC) ratio <0.7 is considered diagnostic of COPD and the severity or degree of airflow impairment as defined by the percentage of the predicted value of FEV_1.0 (Table 16.3).

Table 16.3

Global Initiative for Chronic Obstructive Pulmonary Disease Spirometric Classification of Severity in COPD Based on the FEV_1.0

Severity	Postbronchodilator FEV_1.0/FVC	Postbronchodilator FEV_1.0 Percentage
Mild	<0.70	FEV_1.0 ≥80% predicted
Moderate	<0.70	50% ≤FEV_1.0 <80% predicted
Severe	<0.70	30% ≤FEV_1.0 <50% predicted
Very severe	<0.70	FEV_1.0 <30% of predicted or FEV_1.0 <50% predicted + respiratory failure

From Global Initiative for Chronic Obstructive Lung Disease. Global strategy for the diagnosis, management and prevention of COPD 2015 [Internet]. Fontana (WI): Global Initiative for Chronic Obstructive Lung Disease; [cited 2015 Jul 12]. Available from: http://www.goldcopd.org/

Once COPD has been diagnosed, questionnaires may be used to assess symptoms and health status. The Global Initiative for Chronic Obstructive Lung Disease (GOLD) guidelines (14) recommend the modified British Medical Research Council (mMRC) questionnaire (20) to assess dyspnea and the COPD Assessment Test (5) to evaluate the impact of symptoms on patient health status.

In terms of exercise limitations, COPD is associated with disabling symptoms including dyspnea and fatigue, which are often worse with exertion (14). Clinical abnormalities include skeletal muscle dysfunction, exercise intolerance, and significant morbidity and mortality (19,28,32,33). These impairments may be worsened by and negatively affect physical activity (12). Decline in regular physical activity and exercise over time results in deconditioning (disuse atrophy of the muscles of ambulation), increased dyspnea at lower levels of exertion, and greater functional impairment and disability (27,34,38). Exposure to systemic corticosteroids may also contribute to muscle dysfunction. Deconditioning due to physical inactivity is a major rationale for exercise training as part of comprehensive PR.

Preparticipation Health Screening, Medical History, and Physical Examination

Accurate diagnosis begins with history and physical examination, including history of irritant (smoking, etc.) and allergen exposure, symptoms including dyspnea (rest and/or with exertion), cough and/or wheeze, fatigue, dizziness, and pain. A recent physical examination by a physician and, at a minimum, a recent 12-lead ECG are required. An echocardiogram or similar testing should be obtained in any patient at risk for heart disease. Current or recent CVD requires diagnostic testing and cardiology evaluation with clearance prior to beginning an exercise program. All identified comorbidities should be optimally managed prior to initiating an exercise program.

Optimizing pulmonary mechanics before implementing an exercise program is essential for patients with COPD. Medication management, adherence, and side effects should be assessed. Inhalation is the route of choice for bronchodilators and maintenance corticosteroids. Standard medical therapy for mild COPD includes, at a minimum, a rescue short-acting bronchodilator (usually albuterol, levalbuterol, and/or combination albuterol/ipratropium). Pharmacological management of moderate COPD includes at least one long-acting bronchodilator (usually a long-acting β-agonist and/or a long-acting anticholinergic inhaler) (14). A growing number of long-acting β-agonists, anticholinergics, and inhaled corticosteroids alone or in combination are available to improve both effectiveness and convenience of care tailored to severity of COPD and related symptoms. Those with severe COPD or who are experiencing frequent exacerbations are generally additionally treated with inhaled corticosteroids. Ongoing patient training and assessment to insure effective inhaler technique and adherence to medication regimen is required. Patients unable to demonstrate proper inhaler technique should be considered for a holding chamber.

Patients with COPD may experience hypoxemia during rest, ADL, exercise, and/or sleep. Hypoxemia can result from ventilation/perfusion mismatch, diffusion defect, right-to-left shunt, or alveolar hypoventilation. In COPD, hypoxemia at rest or during low-level exertion is typically caused by ventilation/perfusion mismatch (37). At high exercise intensities, a diffusion deficit may become a contributing factor (16). Supplemental oxygen is usually capable of restoring normal oxygenation. Patients with a right-to-left shunt have a more limited response to supplemental oxygen (9). Hypoxemia may also be triggered by depressed ventilatory drive and is typically accompanied by hypercapnia and low pH. Chronically low ventilatory drive (chronic respiratory acidosis) is associated with hypercapnia and near-normal pH. Hypoxemia is often aggravated with exposure to high altitude or during disease exacerbation. Evaluation of hypoxemia begins with a comprehensive history and physical examination and includes arterial blood gas (ABG) sampling or, at a minimum, noninvasive measurement of arterial oxygen saturation level with a pulse oximeter. Pulse oximetry, however, does not provide information about acid–base balance, carbon dioxide, or bicarbonate levels. Evaluation of hypoxemia during exercise may be performed using either ABG sampling or, more commonly, pulse oximetry (24).

During exercise, demand for oxygen by working muscle increases in proportion to the level of work performed (2). This results in a higher cardiopulmonary demand to deliver oxygen to muscle fibers. For normal individuals, delivery of oxygen (cardiac output × arterial oxygen content) to tissues is regulated by changing cardiac output to meet the metabolic demand of exercise; pulmonary ventilation is increased to prevent decreases in arterial oxygen content. In chronic lung disease, the ability of the lungs to maintain arterial oxygen content may be impaired, resulting in impaired oxygen delivery and reduced exercise ability.

Supplemental oxygen can increase arterial oxygen content (thereby improving tissue oxygen delivery), decrease carotid body stimulation (thereby reducing pulmonary ventilation, respiratory muscle work, and dyspnea), and relieve pulmonary vasoconstriction (thereby alleviating cardiac output restriction). Oxygen improves the effectiveness of short- and long-term exercise training in hypoxemic patients with COPD by reducing dyspnea, hypoxic ventilatory drive, and hyperinflation and by delaying acidosis. Supplemental oxygen allows rehabilitation participants to exercise at higher work rates during their training program. Ambulatory oxygen equipment has the potential to increase mobility, adherence, exercise tolerance, and autonomy in hypoxemic patients. Patients requiring oxygen should undergo titration as part of PR, preferably using the patient’s own ambulatory oxygen system.

Case Study 16-1 Quiz:

Preparticipation Health Screening, Medical History, and Physical Examination

1. Describe criteria for diagnosis and severity of COPD.

2. Identify three factors that affect COPD diagnosis and/or progression.

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