VALIDITY OF CT CLASSIFICATION ON MANAGEMENT OF OCCULT PNEUMOTHORAX - A PROSPECTIVE-STUDY

OBJECTIVE. In the setting of blunt trauma, abdominal CT, which routine ly includes images of the lower thorax, frequently reveals pneumothora ces that have not been detected on routine supine chest radiographs. P roper management of these occult pneumothoraces remains controversial. The purpose of this study was to test the hypothesis that small (minu scule) to moderate (anterior) radiographically occult pneumothoraces c an be safely managed without chest tube placement for patients in whom the need for positive pressure ventilation is not anticipated. SUBJEC TS AND METHODS. We undertook a prospective study in which 44 occult pn eumothoraces were classified into three groups, minuscule, anterior, o r anterolateral, according to size and location on CT scans. Choice of initial management (tube thoracostomy versus close observation) was b ased in part on this classification system and in part on individual c ircumstances of a surgeon's decision. RESULTS. Of the 44 pneumothorace s found in 36 patients, 16 pneumothoraces were minuscule, 20 were ante rior, and eight were anterolateral. Thirteen minuscule pneumothoraces and 11 anterior pneumothoraces initially managed with observation did not require subsequent tube thoracostomy. All eight patients with ante rolateral pneumothoraces underwent tube thoracostomy. CONCLUSION. Most small (minuscule) occult pneumothoraces can successfully be managed w ith close observation. The risk that the pneumothorax will progress is slight. Moderate-sized (anterior) pneumothoraces may also be successf ully managed without initial placement of a chest tube if the patient is not to undergo positive pressure ventilation.