Essential Thoracic Ultrasound Skills for the FAST Exam

The thoracic component of the Focused Assessment with Sonography in Trauma (FAST) examination utilizes ultrasound to identify pneumothorax, pleural effusion, and pericardial effusion in emergency settings. Detecting a pneumothorax requires observing the visceral-parietal pleural interface for lung sliding; the presence of a "lung point" serves as a highly specific diagnostic marker, though subcutaneous emphysema can obstruct the view. Evaluating pleural effusions involves identifying the "spine sign"—where vertebral bodies are visible above the diaphragm—and the "mirror sign," which indicates a normal air-filled lung. In trauma cases, a "plankton sign" within the fluid suggests a hemothorax. Pericardial assessments focus on identifying hypoechoic fluid rims and monitoring for tamponade indicators, such as right ventricular diastolic collapse and a dilated, non-collapsing inferior vena cava. These sonographic markers provide rapid, bedside diagnostic capabilities for identifying life-threatening thoracic injuries and hemodynamic compromise.