Chronic Obstructive Pulmonary Disease: Diagnosis and Treatment

Diagnosis

Pulmonary function testing showing an obstructive pattern is the most reliable indicator for diagnosis. This would be a ratio of forced expiratory volume in 1 second to the forced vital capacity of less than 70% (FEV1/FVC ratio <70%).

Chest x-rays may reveal hyperinflation of the lungs, indicated by flattening of the diaphragm and radiolucency of the lung fields. However, x-rays may appear normal until the emphysema component is quite advanced.

Hematocrit levels may be elevated due to chronic hypoxia.

Arterial blood gas concentration may reveal hypoxia and hypercarbia.

Treatment

Quitting smoking is essential at any stage of the disease. Although lung damage will not be reversed (especially in advanced cases), smoking cessation will lead to improvements in pulmonary function.

Physical exercise, as part of a pulmonary rehabilitation program, can improve functional status in COPD. Exercise programs do not necessarily increase lung function, but they should increase patients' ability to perform activities of daily living. Inspiratory muscle training in particular is associated with significant improvements in pulmonary capacity, endurance, exercise capacity, and dyspnea.¹ As with other forms of exercise, benefits are lost if patients do not maintain their efforts.²

Respiratory therapy and pulmonary rehabilitation improve quality of life and exercise capacity.

Continuous or nighttime supplemental oxygen provides symptomatic relief and improves mortality in patients with chronic hypoxemia.

Bronchodilators, including β2-adrenergic agents (eg, albuterol) and anticholinergics (eg, ipratropium bromide) may alleviate symptoms by reducing bronchial tone. However, some COPD patients will be unresponsive to bronchodilator therapy.

Methylxanthines (eg, theophylline) are a controversial treatment. They may be beneficial by augmenting the action of the diaphragm during exhalation, improving gas exchange, and increasing airway caliber.

The role of corticosteroids is still under investigation. Inhaled steroids, although often prescribed, have not been beneficial in most patients. Systemic steroids may help hospitalized patients with acute exacerbations.

Antibiotics are useful in exacerbations, but should not be used prophylactically.

Surgery

Surgical intervention may be helpful in a minority of advanced cases. Lung-volume-reduction surgery may benefit selected end-stage patients by increasing elastic recoil, improving expiratory airflow, and improving the function of the diaphragm and intercostal muscles. Lung transplantation may also be considered.

Emergency Treatments

Acute exacerbations of COPD must be treated emergently. It is important to identify and treat the cause of the exacerbation (eg, infection, excessive sedation), administer bronchodilator therapy (eg, beta agonists) and supplemental oxygen, ensure clearance of pulmonary secretions, and closely monitor for signs of respiratory failure.

If respiratory failure occurs, intubation may be necessary. Noninvasive positive pressure ventilation (BiPAP) is often used in deteriorating patients, as it may preclude the need for intubation.