IntroductionIn a laparoscopic gastrectomy, the abdominal cavity is insufflated with CO2 to create the best possible operative view. However, laparoscopic surgery may cause severe CO2-related complications, such as pneumothorax, pneumoperitoneum, and subcutaneous emphysema. Although rare, pneumothorax is a recognized potential complication of laparoscopic surgery, with reported incidence rates of up to 2% (Mamić et al., 2016). Although tension pneumothorax is not uncommon among hospitalized patients, fatal cases of this condition are relatively rare. Tension pneumothorax can evolve during the course of a spontaneous pneumothorax or hyperbaric oxygen therapy (Light and Lee, 2016). It is caused by the entry of air into the pleural cavity, which becomes trapped and leads to increased pressure, the potential collapse of the lung, and compression of surrounding structures. Risk factors include positive-pressure ventilation, pre-existing lung disease, or accidental lung or chest wall injury during the surgery (Hillis et al., 2022). Chest radiography (CXR) and computed tomography (CT) have largely been used as lung imaging tools to diagnose abnormal lung conditions in the emergency and critical care settings but the diagnostic accuracy of lung ultrasound for conditions like pleural effusion, pneumothorax, pulmonary edema and pneumonia is superior to chest radiograph and is comparable to chest CT scan. Treatment typically involves the insertion of a chest tube to allow the trapped air to escape and restore normal pressure within the pleural cavity (Cunningham and Brull, 1993, Mehran et al., 2004, Labow and Conlon, 1999). As misdiagnoses and inadequate management of TPT can lead to severe adverse outcomes, a comprehensive description of clinical presentation and its management may improve patient care. Here, we report a case of a patient who underwent laparoscopic proximal gastrectomy but later developed tension pneumothorax during the procedure.