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

Abstract

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.