Internal Medicine

P1: RLJ/OZN P2: PSB

0521779407-D-02 CUNY1086/Karliner 0 521 77940 7 June 4, 2007 21:9

516 Dyspnea

➣Acute onset: bronchospasm, pulmonary embolus, pneumotho-

rax, pulmonary edema, angina, myocardial infarction, dysrhyth-

mia

➣Gradual onset:

Cardiac: coronary artery disease; CHF, valvular disease;

dysrhythmia; pericardial tamponade

Pulmonary:

Obstructive lung disease (asthma, COPD, bronchiectasis):

often with wheeze or cough, smoking associated with COPD,

exertional dyspnea progressing gradually to dyspnea at rest,

PFT to quantify degree of obstruction (spirometry) and diffu-

sion abnormality (DLCO)

■Diffuse parenchymal/ILD (idiopathic pulmonary fibrosis, sarcoido-

sis, pneumoconioses): gradually progressive dyspnea on exertion,

restriction on PFTs (decreased TLC, normal or elevated FEV1/FVC),

HRCT often useful

➣Pulmonary infection (pneumonia, bronchitis): dyspnea may pre-

cede CXR findings

➣Atelectasis: secondary to tumor, mucus plug, foreign body,

breathing patternPleural disease: malignancy (mesothelioma),

infection (including TB), collagen vascular disease, nephrotic

syndrome, liver disease

➣Pulmonary vascular disease: pulmonary embolism, vasculitis

(SLE, polyarteritis nodosa, rheumatoid arthritis), venoocclu-

sive disease, primary pulmonary hypertension, schistosomiasis;

CXR may be normal with pulmonary embolus and pulmonary

hypertension; decreased DLCO without obstruction or restric-

tion suggests pulmonary vascular disease

➣Diseases of chest wall/respiratory muscle weakness: cause

restriction, resulting in dyspnea; neurologic disease can cause

respiratory muscle weakness

Other

■Malignancy/anemia: fatigue and/or effusions contribute to dyspnea

■Anxiety: difficult to evaluate; hyperventilation; history of stress; no

relation to activity; variability minute-to-minute; not during sleep

management

What to Do First

■Assess cause; determine if acute or gradual; SaO 2 , CXR, ECG, ABG;

treat emergent conditions as warranted