PNEUMONIA AND ARDS IN PATIENTS RECEIVING MECHANICAL VENTILATION - DIAGNOSTIC-ACCURACY OF CHEST RADIOGRAPHY

This study was done to evaluate the diagnostic accuracy of bedside che st radiography for pneumonia, adult respiratory distress syndrome (ARD S), or both in patients receiving mechanical ventilation. The series c onsisted of 40 patients; diagnostic accuracy was defined as the area u nder the receiver operating characteristic curve. Overall diagnostic a ccuracy for ARDS was 0.84. Overall diagnostic accuracy for pneumonia w as 0.52. Review of previous radiographs and knowledge of clinical data did not enhance diagnostic accuracy for ARDS or pneumonia. Diagnostic accuracy for pneumonia was minimally reduced when ARDS was present. T here was an increase in false-negative results because the diffuse are as of increased opacity in ARDS obscured the radiographic features of pneumonia. The authors conclude that chest radiography is of limited v alue for the diagnosis of pneumonia in patients receiving mechanical v entilation. The high false-negative and false-positive ratings for pne umonia resulted in a low diagnostic accuracy. The high diagnostic accu racy for ARDS was primarily due to the well-defined radiographic appea rance of ARDS and few false-positive ratings.