Overview Snapshot A 13-year-old boy with cystic fibrosis presents to the emergency department with S. aureus pneumonia. He suddenly develops increased respiratory distress, pleuritic chest pain, and decreased breath sounds in the left chest. Introduction Pneumothorax results from air trapped in the pleural space that collapses a portion of the ipsilateral lung Etiologies primary spontaneous caused by rupture of the subpleural apical blebs usually occurs in tall, thin males secondary spontaneous spontaneous pneumothorax in the setting of underlying lung disease (ie COPD, TB, trauma, pneumocystis pneumonia, S. aureus) trauma including iatrogenic subclavian access has the highest risk of pneumothorax due to the proximity to the apices of the lungs Presentation Symptoms sudden-onset, unilateral, pleuritic chest pain dyspnea acute respiratory distress Physical exam decreased or absent breath sounds hyperresonant to percussion decreased or absent tactile fremitus may see tracheal deviation if tension pneumothorax present Evaluation CXR diagnostic gold standard in upright patient