Snapshot A 34-year-old man arrives at the emergency department by ambulance following a motorcycle accident. He was intubated in the field. On inspiration, the right side of his chest retracts. CT scan reveals several broken ribs. Introduction Open pneumothorax results from large open defects of the chest wall usually secondary to blunt trauma Leads to immediate equilibration of atmospheric pressure and intrathoracic pressure causing collapsed lung Presentation Symptoms unilateral pleuritic chest pain acute respiratory distress Physical exam flail chest unilateral retraction with contralateral expansion on inspiration unilateral diminished or absent breath sounds contralateral hyperesonance decreased tactile fremitus Evaluation CXR diagnostic golden standard unilateral pneumothorax may show broken ribs CT usually ordered as part of trauma protocol Differential Tension pneumothorax, flail chest without pneumothorax Treatment Non-operative aggresively manage vitals O2 saturation, HR, BP must treat operatively for resolution Operative promptly close defect with sterile occlusive dressing and tape on three sides creating one-way valve that allows air to escape place chest tube remote from wound site definitive surgical closure is often later required Prognosis, Prevention, and Complications Prognosis not as immediately critical as tension pneumothorax Prevention early intervention can slow progression to tension pneumothorax Complications if left untreated, can result in tension pneumothorax leading to shock and death