pulmonary disorders
Dyspnea
Key Points
Pulse oximetry is a key component of the examination. Low oxygen saturation (<90%) indicates a serious problem, but normal saturation does not rule one out. Accessory muscle use, a sudden decrease in oxygen saturation, or a decreased level of consciousness requires emergency evaluation and hospitalization. Myocardial ischemia and pulmonary embolism are relatively common, but symptoms and signs can be nonspecific. Exacerbation of known conditions (eg, asthma, chronic obstructive pulmonary disease, heart failure) is common, but patients may also develop new problems. 