Dyspnea is a common end-stage condition in patients with chronic obstructive pulmonary disease (COPD). Symptoms of dyspnea can be obvious, such as rapid breathing with pursed lips, or more subtle, such as difficulty speaking a long sentence or laughing. Interestingly, dyspnea severity does not correlate with forced expiratory flow in one second (FEV₁) and may improve or worsen without any corresponding expiratory flow changes. Runo and Ely reviewed the literature for evidence about treatments for dyspnea accompanying COPD.

Both randomized and blinded trials were reviewed as well as meta-analyses, a single case series, and a consensus statement. Oxygen therapy improves dyspnea when mild or severe hypoxemia is present at rest or with exercise. Exercise tolerance is often improved with higher oxygen flow rates. Bronchodilator therapy, including inhaled beta agonists and anticholinergic agents, relieves dyspnea. Anticholinergic agents like ipratropium bromide appear to have a longer duration of action and provide greater improvement in dyspnea symptoms than beta agonists. Combining an anticholinergic agent with a beta agonist seems to provide more improvement than either agent used alone. Longer-acting beta agonists like salmeterol xinafoate provide greater improvement in dyspneic patients. Metered dose inhalers (MDIs) are the preferred initial delivery system because of decreased cost, greater ease of use, and the lack of documented benefit of administration by nebulizers. Nebulization is the preferred system, however, in weaker patients who cannot effectively use an MDI.

Theophylline can provide some relief from dyspnea, but it must be used carefully because of potential drug interactions and the need to maintain blood levels within the narrow therapeutic range of 10 to 12 μg per mL. Anxiolytic agents have shown no clear efficacy in relieving dyspnea symptoms. Buspirone, which has minimal side effects and addiction potential, has been used with slightly more success than the other anxiolytics. Promethazine may have a beneficial effect. Antidepressants have not demonstrated efficacy in relieving dyspnea. Oral opioids like morphine sulfate, codeine, and dextromethorphan hydrobromide have minimal efficacy and multiple side effects and, consequently, should not be used routinely in dyspneic patients. Inhaled opioids also have little benefit and are rarely used for this purpose. Oral opioids may have some palliative value in relieving dyspnea in patients with end-stage COPD.

Pulmonary rehabilitation programs that include education and structured exercise can reduce dyspnea and increase exercise capacity. The use of an inspiratory resistance breathing device may also increase muscle strength and make patients more comfortable at rest and with exertion, but results have been mixed. Lung volume surgery may improve dyspnea in the short term, but it is expensive, invasive, and less efficacious in end-stage patients. The accompanying table summarizes available therapies and their efficacy.

The authors conclude that most patients with dyspnea secondary to COPD should be given influenza and pneumococcal vaccines and administered low-flow oxygen at night and with exertion. An inhaled combination of beta agonist and anticholinergic would be helpful. Salmeterol should be reserved for use in the more dyspneic patients. Buspirone, an anxiolytic, may be used if there is intense anxiety associated with more severe episodes of dyspnea. Pulmonary rehabilitation with active exercises can also decrease dyspnea. If these therapies do not work, and dyspnea worsens, theophylline and/or an oral opioid may be offered.

editor's note: Although it makes sense that anti-inflammatory treatment with inhaled corticosteroids would benefit patients with COPD who develop airway inflammation, the benefit of corticosteroid therapy in patients with COPD has not been well established. Bone and eye complications accompanying steroid use have reduced interest in long-term therapy. Some studies using inhaled triamcinolone have shown improved airway reactivity and respiratory symptoms, and decreased use of health care services, but no change in the rate of lung function decline. As a last resort, acute exacerbations of COPD can be treated effectively with systemic corticosteroids.—r.s.