Abstract
We prospectively studied the lung function of 106 consecutive young patients with pneumonia. At the time of hospital admission we observed impaired spirometric function in 48% of the patients. During and following treatment, the frequency of abnormalities in pulmonary function tests decreased rapidly. However, at the 15th day of hospitalization, abnormal ventilatory function was still demonstrated in 21% of the patients. Such prolonged impairment of ventilatory function was significantly more likely to result from pneumonia caused by Mycoplasma pneumoniae than from forms caused by adenovirus or Streptococcus pneumoniae.