THE APPEARANCE OF EARLY CHEST RADIOGRAPHS AND THE RESPONSE TO SURFACTANT REPLACEMENT THERAPY

We have assessed whether the appearance of the chest radiograph perfor med within the first 2 h of birth was predictive of the response to ex ogenous surfactant replacement therapy (SRT), as indicated by changes in sensitive indices of disease severity, that is lung volume (functio nal residual capacity (FRC)) and oxygenation (a/A ratio). 18 premature infants who received two doses of a synthetic surfactant (Exosurf) we re studied. The appearances of chest radiographs taken prior to the fi rst and immediately after the second dose of SRT were scored for lung volume, degree of inflation, presence of opacification, interstitial s hadows and air bronchograms. At similar times, FRC was measured and th e a!A ratio calculated. Although following SRT? the chest radiograph s core decreased (p<0.01) and the FRC (p<0.01) and a/A ratio (ns) improv ed, there was no significant relationship between the change in chest radiograph score and either the change in FRC or a/A ratio. In additio n, only the post-SRT chest radiograph appearance correlated significan tly with the respective FRC, a/A ratio and outcome (death or oxygen de pendency beyond 28 days). Although the appearance of an early chest ra diograph is frequently used as an indicator of the need for SRT, these results demonstrate that, unlike the post-SRT radiograph, it is a poo r predictor of the response to SRT and outcome.