Diagnostic Testing
At the bedside, cough in the absence of fever, tachycardia,and tachypnea suggests bronchitis, rather than pneumonia. In fact, the presence of normal vital signs and the absence of rales and egophony on chest examination minimize the likelihood of pneumonia to the point at which further diagnostic testing is usually unnecessary.28 An exception, however, is cough in elderly patients; pneumonia in elderly patients is often characterized by an absence of distinctive signs and symptoms. Among patients 75 years of age or older who had community-acquired pneumonia, only 30% had a temperature above 38°C, and only 37% had a heart rate of more than 100 beats per minute.