Chronic obstructive pulmonary disease (COPD)

Background

• Chronic obstructive pulmonary disease (COPD) is characterized by significant airflow limitation associated with a chronic inflammatory response in the airways and lungs resulting in the destruction of lung tissue.
  • It commonly affects adults > 40 years old who experience significant exposure to combusted tobacco, with an estimated worldwide prevalence of about 11%, with about 14.3% in males and 7.6% in females.
  • The disease course is usually progressive with a long-term decline in lung function, and it is among the top 3 leading causes of mortality worldwide. Up to 90% of COPD deaths are reported to occur in low- and middle-income countries.
  • It is a preventable and treatable disease that is commonly associated with comorbidities (such as, cardiovascular disease) and significant systemic consequences (such as, skeletal muscle dysfunction).
• Use of combusted tobacco is a major risk factor for COPD worldwide and the most common risk factor in high-income countries. Outdoor air pollution, such as from urban environments or wildfire smoke, is the leading known risk factor for COPD in people who have never smoked and accounts for approximately 50% of COPD risk in low- and middle-income countries. Other risk factors include occupational exposures (for example, organic and inorganic dusts, chemical agents, and fumes), alpha-1 antitrypsin (AAT) deficiency, and indoor air pollution (particularly from smoke that is caused from burning biomass fuels in confined spaces).
• COPD has several complications, including acute exacerbation, respiratory failure, and pulmonary hypertension.
• Four-year mortality rates range from 28% for mild-to-moderate COPD to 62% for moderate-to-severe COPD.

Evaluation

• Suspect a diagnosis of COPD in patients with chronic and progressive dyspnea, cough, and/or sputum production, who have a history of combusted tobacco use, a strong family history of airway disease, or who have been exposed to other risk factors.
• Recognize that a physical examination has a limited utility for diagnosing COPD.
  • Findings consistent with COPD include the use of accessory respiratory muscles (scalene or sternocleidomastoid), pursed-lip breathing, reduced chest expansion, hyperresonance to percussion, and reduced breath sounds.
  • A physical examination may also help detect the signs of acute exacerbation of COPD, such as central cyanosis, hemodynamic instability, and reduced alertness.
• Perform spirometry to assess the forced expiratory volume in 1 second (FEV₁) and forced vital capacity (FVC) (Strong recommendation).
  • A postbronchodilator FEV₁/FVC ratio < 0.7 is consistent with a diagnosis of COPD.
  • FEV₁ (as a percentage of the predicted FEV₁) is used to assess the severity of the disease, but Global Initiative for Chronic Obstructive Lung Disease (GOLD) grouping should be used to guide initial treatment strategy rather than FEV₁ alone.

Table 1. GOLD Classification for Severity of Airflow Limitation

• Additional testing for a patient workup may include measuring diffusing capacity of the lung for carbon monoxide (for patients with COPD and symptoms such as dyspnea disproportionate to degree of airflow obstruction), measuring oxygen saturation by pulse oximetry and/or arterial blood gas, a complete blood count, alpha-1 antitrypsin screening, chest x-ray, or computed tomography. Computed tomography (CT) is not routinely used but may be helpful when symptoms are disproportionate to disease severity, and is used for annual low-dose screening for suspected lung cancer in patients with COPD due to smoking (see also Lung Cancer Screening).
• Global Initiative for Chronic Obstructive Lung Disease (GOLD) severity assessments include:
  • Modified Medical Research Council (mMRC) questionnaire, which evaluates breathlessness based on scale of 0 (breathless with strenuous exercise) to 4 (too breathless to leave the house or breathless when dressing or undressing).
  • COPD Assessment Test (CAT), which is an 8-item questionnaire worth up to 5 points each (overall score range 0-40) that may aid in determining disease-specific, health-related quality of life (see CAT 2018 for questionnaire and user guide).

Table 2. GOLD Severity Assessment Groups to Guide Initial Management Based on Symptom Burden and Risk of Exacerbation in Past Year

• The body mass index/airflow obstruction/dyspnea/exercise capacity (BODE) index is scored on a 1- to 10-point scale and it can help stratify patients based on the risk of mortality.
• While classically AAT deficiency is more likely in patients with possible COPD who are young, who have a positive family history of COPD at a young age, emphysema without risk factors, and in those with panlobular basal emphysema, consider screening in all patients with COPD, especially in areas with a high AAT deficiency prevalence (Weak recommendation).

Management

• See Acute Exacerbation of COPD for management of acute COPD exacerbations and see Alpha-1 Antitrypsin (AAT) Deficiency for management in COPD patients with AAT deficiency.
• For all patients:
  • Encourage smoking cessation for patients who continue to use combusted tobacco (Strong recommendation).
  • Administer an influenza vaccination annually (Strong recommendation).
  • Administer a pneumococcal polysaccharide vaccination (Strong recommendation).
  • Administer a COVID-19 vaccine in line with national recommendations (Strong recommendation).
  • Consider administering a Tdap (tetanus, diphtheria, and acellular pertussis) vaccine in adults with COPD who did not have vaccination in adolescence and zoster vaccine to patients with COPD > 50 years old (Weak recommendation).
• Pulmonary rehabilitation is recommended for patients with symptoms and/or a high risk of exacerbation (Strong recommendation).
• Initial management by disease severity:
  • for GOLD group A patients, first-line drug therapy is short- or long-acting bronchodilator (Strong recommendation) with long-acting bronchodilator preferred unless only very occasional dyspnea is present
  • for GOLD group B patients, first-line drug therapy is long-acting bronchodilator combination therapy with long-acting muscarinic receptor antagonist (LAMA) plus long-acting beta-2 agonist (LABA) (Strong recommendation)
  • for GOLD group E patients, first-line drug therapy is LABA/LAMA combination therapy (Strong recommendation)
    • Consider triple therapy with LAMA/LABA plus an inhaled corticosteroid (ICS) if the patient's blood eosinophil count is ≥ 300 cells/mcL or if the patient has a history of, or concomitant, asthma.
    • Combination therapy of only LABA plus ICS is discouraged.
    • if patient has history of asthma or findings suggestive of comorbid asthma, addition of ICS is mandatory, as management of these patients should primarily follow asthma guidelines (see also Asthma-COPD Overlap (ACO)) (Strong recommendation)
• Suggested follow-up management based on symptom history (regardless of the initial ABE group assessment at the diagnosis):
  • if response to initial treatment is appropriate, maintain initial therapy; if not, assess adherence, inhaler technique, and possible comorbidities; consider predominant symptom to target (persistent dyspnea/exercise limitation or persistent exacerbations); adjust regimen; assess response, and continue to adjust and review
  • predominant symptom to target and current therapy regimen will guide follow-up treatment for persistent symptoms, but generally involves addition of a second long-acting bronchodilator class or switching to triple therapy with LABA/LAMA/ICS; management with only LABA/ICS combination therapy is discouraged
• Other treatments:
  • In patients with severe, chronic resting arterial hypoxemia (partial pressure of oxygen [PaO₂] ≤ 7.3 kilopascal [55 mm Hg] or oxygen saturation ≤ 88%) offer continuous oxygen therapy (Strong recommendation).
  • Consider long-term noninvasive ventilation in addition to usual care for patients with chronic, stable hypercapnic COPD (such as, those with resting arterial carbon dioxide partial pressure [PaCO₂] > 45 mm Hg), especially if persistent hypercapnia after recent hospitalization for acute respiratory failure (Weak recommendation).
  • Other medications may be considered for COPD symptom control, such as, roflumilast, theophylline, and short-term oral corticosteroids for symptom control in specific clinical situations, such as when patients demonstrate intolerance to LABA, LAMAs, or ICS or according to patient preferences regarding concerns over side effects. Long-term use of oral corticosteroids shows no long-term benefit with significant risk of adverse events.
  • Consider lung volume reduction surgery in patients with heterogeneous (upper-lobe predominant) emphysema and low postrehabilitation exercise capacity.
  • Bronchoscopic lung volume reduction (nonsurgical) is an option for selected patients with advanced emphysema without large bulla. Options include endobronchial valves, lung coils, and vapor ablation, but endobronchial valves are only useful in patients with fissure integrity and lack of collateral ventilation.
  • Consider a lung transplant in selected patients with end-stage COPD (Weak recommendation), as it may improve quality of life and functional capacity.
• Lung cancer is commonly seen in patients with COPD and is a major cause of death. Patients with smoking-related COPD should be screened annually if they are between ages 50 and 80 years, have a ≥ 20 pack-year smoking history, and are current smokers or have quit < 15 years ago (Strong recommendation).
• Do not treat most patients with stable COPD with prophylactic antibiotics.