Approach to the Patient: Dyspnea

History: Obtain description of discomfort, including the impact of position, infections, and environmental exposures (Fig. 33-1). Orthopnea is commonly observed in CHF. Nocturnal dyspnea is seen in CHF and asthma. Acute intermittent dyspnea suggests myocardial ischemia, asthma, or pulmonary embolism.

Physical examination: Assess increased work of breathing indicated by accessory ventilatory muscle use. Determine if chest movement is symmetric. Use percussion (dullness or hyperresonance) and auscultation (decreased or adventitious breath sounds) to assess the lungs. Cardiac examination should note jugular venous distention, heart murmurs, and S3 or S4 gallops. Clubbing can relate to interstitial lung disease or lung cancer. To evaluate exertional dyspnea, reproduce the dyspnea with observation while assessing pulse oximetry.

Radiographic studies: Chest radiograph should be obtained as initial evaluation. Chest CT can be used subsequently to assess lung parenchyma (e.g., emphysema or interstitial lung disease) and pulmonary embolism.

Laboratory studies: ECG should be obtained; echocardiography can assess left ventricular dysfunction, pulmonary hypertension, and valvular disease. Pulmonary function tests to consider include spirometry, lung volumes, and diffusing capacity. Methacholine challenge testing can assess for asthma in subjects with normal spirometry. Cardiopulmonary exercise testing can determine whether pulmonary or cardiac disease limits exercise capacity.

Treatment: Dyspnea

Ideally, treatment involves correcting the underlying problem that caused dyspnea. Supplemental oxygen is required for significant oxygen desaturation at rest or with exertion. Pulmonary rehabilitation is helpful to improve exercise tolerance in COPD.