The usefulness of chest radiographs in first asthma attacks.

To assess the value of routine chest radiography during acute first attacks of asthma, we studied 371 consecutive children over one year of age who presented with an initial episode of wheezing. Three hundred fifty children (94.3 per cent) had radiographic findings that were compatible with uncomplicated asthma and were considered negative. Twenty-one (5.7 per cent) had positive findings: atelectasis and pneumonia were noted in seven, segmental atelectasis in six, pneumonia in five, multiple areas of subsegmental atelectasis in two, and pneumomediastinum in one. The patients with positive films were more likely to have a respiratory rate above 60 or a pulse rate above 160 (P less than 0.001), localized rales or localized decreased breath sounds before treatment (P less than 0.01), and localized rales (P less than 0.005) and localized wheezing (P less than 0.02) after treatment; also, these patients were admitted to the hospital more often (P less than 0.001). Ninety-five per cent (20 of 21) of the children with positive films could be identified before treatment on the basis of a combination of tachypnea, tachycardia, fever, and localized rales or localized decreased breath sounds. Most first-time wheezers will not have positive radiographs; careful clinical evaluation should reveal which patients will have abnormal radiographs and will therefore benefit from the procedure.