Synchronization of radiograph film exposure with the inspiratory pause - Effect on the appearance of bedside chest radiographs in mechanically ventilated patients

The appearance of portable chest radiographs (CXRs) may be affected by chan ges in ventilation, particularly when patients are mechanically ventilated. Synchronization of the CXR with the ventilatory cycle should limit the inf luence of respiratory variation on the appearance of the CXR. This study ev aluates the effect of synchronizing the CXR film exposure with ventilation on the appearance of the radiograph. Twenty-five patients who remained intu bated postoperatively, were mechanically ventilated, and required a CXR wer e enrolled in this triple-blind, randomized prospective study. Each patient received one radiograph using conventional techniques and another using th e interface. The sequence of the two films was randomized, and the two film s were taken on the same patient within a few minutes of each other. Hence, each patient served as his own control and the position of the patient, so urce-film distance, intensity (Kvp), and duration of the exposure (mAs) wer e identical for the two films. Five board-certified radiologists were then asked to compare paired films for clarity of lines and tubes, definition of the pulmonary vasculature, visibility of the mediastinum, definition of th e diaphragm, and degree of lung inflation. Radiologists were also asked to choose which films they preferred. A majority of board certified radiologis ts preferred CXRs taken with the interface in 21 of 25 patients (p < 0.0001 ). Furthermore, four of the five criteria evaluated were improved (p < 0.05 ) on synchronized CXRs. Synchronization of the bedside CXR with the end of inspiration ensures that they are always obtained at maximal inflation, whi ch improves the appearance of a majority of radiographs by at least one of five criteria.