The Use of Chest Sonography in Diagnosing Pneumothorax in Mechanically Ventilated Patients

Abstract

Backergound: To evaluate the role of chest sonography in the diagnosis of pneumothorax in mechanically ventilated patients. Methods: The 21 mechanically ventilated patients enrolled in this study presented with a sudden onset of shortness of breath ,an abrupt incrase of peak airway pressure,and arterial desaturation combined with unilateral or bilateral decrease in breath suouds,or had suspicions of pneumothorax based on chest radiographs. Chest sonographic studies were performed in call of these patients. We defined the disappearance of both the “gliding sign ” abd the “comet-tail” artifact as positive ultrasonic findings of pneumothorax. The gold standard we used was one of the following : a gush of air noted after placement of a large-bore needle into the pleural space, continuous air leakage from the chest tube,or obvious pneumothorax on the anteroposterior or lateral decubitus view of the chest radiograph. Results: In the study population, sonographic studies were positive in 10if tge 21 cases. Five of the 10 had hypotension, and emergent large-bore needles were inserted. Eleven of the 21cases showed no sonographic evidence of pneumothorax ,and subsequent chest radiographs also confirmed that. No false positives or false negatives were found. Conclusion: Chest sonography is both highly sensitive and specific for the diagnosis of pneumothorax in mechanically ventilated patients. Therefore, we recommend the use of sonography as an alternative diagnostic tool in mechanically ventilated patients who are suspected of having developed pneumothorax but who can not be definitely diagnosed otherwise.