A case of lung point sign in a patient with pneumothorax under high frequency oscillatory ventilation

Pneumothorax is a frequent problem seen in the intensive care unit (ICU). Lung ultrasound has demonstrated to be a useful method in the diagnosis of pneumothorax with high accuracy. The normal lung is characterized by the presence of lung sliding (Video 1). The pattern observed in pneumothorax by ultrasound are the abolition of lung sliding (Video 2) and the lung point sign (Video 3) which has been shown to have 100% specificity for its diagnosis. 1 The lung point sign is defined as an respiratory-synchronized change from lung sliding to no lung sliding in a specific location on the chest wall. 2 We present a case of pneumothorax with the lung point sign in a patient under high frequency oscillatory ventilation (HFOV). A 16-year-old patient suffering respiratory insufficiency due to acute respiratory distress syndrome was admitted to intensive care unit (ICU) requiring HFOV. Because he evolved with greater hypox-emia, we evaluated the lung with point-of-care ultrasound (POCUS). It showed at the anterior right chest the presence of the lung point sign compatible with pneumothorax. Specially, the lung sliding pre-sented a high-frequency movement in accordance with its ventilator mode, which made the lung point sign so peculiar (Video 4). The diagnosis was confirmed by chest X-ray. The patient required the placement of a right pleural drainage tube, evolving with improved oxygenation. It should be noted that there are situations where ultrasonography may fail to correctly rule a pneumothorax in or out.