Snapshot A 56-year-old male with a history of chronic obstructive pulmonary disease presents with pleuritic chest pain and trouble breathing. Vital signs are significant for a blood pressure of 88/54 mmHg and a pulse of 115/min. On exam, there is jugular venous distension, decreased breath sounds on the right side, with wheezes. A chest radiograph is obtained. Introduction Tension pneumothorax results from positive pressure build-up secondary to a flap valve mechanism (or one-way valve) resulting in total lung collapse tracheal shifting to opposite end expansion of chest wall Increased intrathoracic pressure restricts cardiac output may result in shock and death ETIOLOGY Etiologies include penetrating and blunt chest trauma infection positive-pressure mechanical ventilation iatrogenic placement of central venous line epidural thoracic catheter placement Presentation Symptoms acute-onset, unilateral, pleuritic chest pain dyspnea/acute respiratory distress syncope Physical exam tachypnea and tachycardia unilateral decreased or absent breath sounds hyperresonance decreased or absent tactile fremitus falling O2 saturation deviated trachea JVD hypotension subcutaneous emphysema IMAGING Ultrasound fast with no radiation exposure requires a bedside ultrasound readily available guidance for tube placement Chest radiography (CXR) do not obtain CXR if tension pneumothorax is suspected - immediately decompress the pleural space best observed in end-expiratory films shows unilateral absence lung parenchyma and contralateral mediastinal shift Differential Primary spontaneous pneumothorax, secondary pneumothorax, acute asthma, inhalation of foreign object, myocardial infarction, ruptured aortic aneurysm Tracheobronchial rupture if a recurrent pneumothorax that recurs after chest tube placement Treatment/Management Prevention no preventive measures can be taken for initial insult chest tube placement following needle decompression prevents recurrence Non-operative do not resolve spontaneously unlike small, simple pneumothoraces supplemental O2 therapy following operative intervention may be required Operative immediate needle decompression second intercostal space at the midclavicular line with 14 or 16-gauge needle followed by chest tube placement Complications Shock and death if left untreated Prognosis Shock and death will result if not immediately recognized and treated