Incidental Diagnosis of Left Pneumothorax Using a New Variant of the Lung Point Sign During Cardiac Ultrasound

Abstract

BackgroundPneumothorax is a common issue in the intensive care unit and emergency department, often diagnosed using lung ultrasound. The absence of lung sliding and the presence of the lung point sign are characteristic findings for pneumothorax. We describe a case of left pneumothorax diagnosed incidentally while performing a cardiac ultrasound through a new variant of the lung point sign. Case ReportA 60-year-old patient with a medical history of diabetes, stroke, and right colon cancer underwent urgent surgical treatment for intestinal sub-occlusion. In the intensive care unit, the patient required mechanical ventilation due to shock unresponsive to fluid administration, and hemodynamic monitoring was performed using echocardiography. During systole in an apical four-chamber view, the abrupt vanishing of the heart was observed. When evaluating the tricuspid annular plane systolic excursion (TAPSE) using M-mode, the interposition of the stratosphere sign during mid-systole prevented the visualization of the TAPSE peak. Lung ultrasound revealed the absence of lung sliding and the presence of the lung point sign on the left side of the thorax, confirming the diagnosis of pneumothorax. A chest x-ray study further confirmed the diagnosis, and urgent drainage was performed. The patient showed improvement in hemodynamic and respiratory conditions and was successfully weaned from mechanical ventilation, and eventually discharged home. Why Should an Emergency Physician Be Aware of This?By incorporating the lung ultrasound findings, including this new variant of the lung point sign, into their diagnostic approach to pneumothorax, emergency physicians can promptly initiate appropriate intervention, such as chest tube insertion, leading to improved patient outcomes.