[Computed tomography in the diagnosis of pulmonary barotrauma associated with the adult respiratory distress syndrome]

Abstract

In the patients suffering from adult respiratory distress syndrome (ARDS), pulmonary barotrauma is a frequent and fearful complication, whose timely and accurate diagnosis is therefore needed. To this purpose, bedside chest films often exhibit some diagnostic drawbacks. Computed tomography (CT) of the chest is rarely used because of the problems concerning the transfer and the control of these critically ill patients outside the Intensive Care Unit. The chest CT findings of 84 ARDS patients were retrospectively reviewed, investigating: a) the presence of barotrauma (pulmonary bullae, pneumothorax, pneumomediastinum, subcutaneous emphysema); b) the positioning of thoracostomy tubes; c) the chest films performed on the same day as CT. CT showed the presence of barotrauma in 41 patients. Pulmonary bullae were seen in 26 cases (31%), pneumothorax (mainly in anteromedial location) in 27 cases (32%) and pneumomediastinum in 11 cases (13%). In 22 patients with thoracostomy tubes CT demonstrated the exact site of the drainages: in 7 cases only the tubes were correctly positioned, or were working properly. The presence of pulmonary bullae (regarded as the evidence of interstitial pulmonary emphysema) proved to be associated with a higher mortality rate than that of the entire sample (58% vs 38%); in 30 of 41 patients with barotrauma (73%) CT proved to be superior to chest films, especially to demonstrate pulmonary bullae (26 cases detected by CT vs 7 cases diagnosed by chest films). In 14 of 41 patients with barotrauma the information yielded by CT directed the choice of treatment: thoracostomy tubes were positioned in the cases of pneumothorax undetected by chest films and in the cases of only partially drained multilocular pneumothorax, or replaced in the event of tube mispositioning. In conclusions, in ARDS patients the use of chest CT is recommended in selected cases only, when complications (especially barotrauma) are suspected and unrevealed by bedside chest films.