Sonographic diagnosis of pneumothorax

Lung sonography has rapidly emerged as a reliable technique in the evaluation of various thoracic diseases. One important, well-established application is the diagnosis of a pneumothorax. Prompt and accurate diagnosis of a pneumothorax in the management of a critical patient can prevent the progression into a life-threatening situation. Sonographic signs, including 'lung sliding', 'B-lines' or 'comet tail artifacts', 'A-lines', and 'the lung point sign' can help in the diagnosis of a pneumothorax. Ultrasound has a higher sensitivity than the traditional upright anteroposterior chest radiography (CXR) for the detection of a pneumothorax. Small occult pneumothoraces may be missed on CXR during a busy trauma scenario, and CXR may not always be feasible in critically ill patients. Computed tomography, the gold standard for the detection of pneumothorax, requires patients to be transported out of the clinical area, compromising their hemodynamic stability and delaying the diagnosis. As ultrasound machines have become more portable and easier to use, lung sonography now allows a rapid evaluation of an unstable patient, at the bedside. These advantages combined with the low cost and ease of use, have allowed thoracic sonography to become a useful modality in many clinical settings.