A bedside ultrasound sign ruling out pneumothorax in the critically ill. Lung sliding.

STUDY OBJECTIVES To describe and evaluate an ultrasound pattern useful in the diagnosis of pneumothorax. DESIGN Ultrasound examination of "lung sliding," a respiratory movement visible when investigating the chest wall. SETTING The medical ICU of a university-affiliated hospital. PATIENTS The study group included 43 proved pneumothoraces, either by chest radiograph (n = 40) or by CT (n = 3). The control group included 68 hemithoraces in which the absence of pneumothorax was proved by CT. INTERVENTION Analysis of anterior chest wall in supine patients. MEASUREMENTS AND RESULTS Feasibility was 98.1%. Disappearance of "lung sliding" was observed in 100% of 41 analyzable cases of pneumothorax vs 8.8% of the hemithorax without pneumothorax (6 of 68). In this series, sensitivity was 95.3%, specificity 91.1%, and negative predictive value 100% (p < 0.001). CONCLUSIONS Ultrasound was a sensitive test for detection of pneumothorax, although false-positive cases were noted. The principal value of this test was that it could immediately exclude anterior pneumothorax.