[Point-of-Care Ultrasonography Developed in Emergency and Critical Care Medicine and Its Application to the Lungs].

The performance of ultrasound (US) devices is improving every year, and more advanced US is being conducted in laboratory settings with high-end machines. Meanwhile, portable US devices, which have become less expensive and of a higher quality, have come into widespread use at bedsides in emergency rooms, intensive care units, and general wards. In recent years, the concept of point-of-care ultrasonography (POCUS) has been widely accepted. POCUS performed at the bedside in acute care settings has value if it gives clinicians useful clinical information in a short time. The findings are interpreted based on the vital signs, history, and physical examination during the scan, and the interpretations are rapidly applied for decision-making. In this article, we review the findings of lung US, which is one of the main fields in POCUS, as well as diagnoses and evaluations of pneumothorax and pulmonary edema in acute care settings.