Snapshot A 22-year-old man presents to the emergency department with chest pain. He was playing basketball when his symptoms suddenly started. The patient is a tall man, and there is no observable trauma to the chest wall. He is hemodynamically stable and currently endorses pleuritic chest pain. (Pneumothorax) Introduction Clinical definition air entry into the chest cavity that causes collapse of the lung without signs of tension physiology (hypotension, tachycardia, and jugular venous distention (JVD)) primary pneumothorax no underlying pulmonary disease secondary pneumothorax underlying pulmonary disease Epidemiology Demographics primary pneumothorax tall and thin men Risk factors secondary pneumothorax smoking ETIOLOGY Pathogenesis mechanism rupture of an emphysematous bleb Associated conditions primary pneumothorax a spontaneous process secondary pneumothorax COPD asthma cystic fibrosis infection (pneumonia, abscess, and tuberculosis) interstitial lung disease connective tissue disease procedures (subclavian lines, thoracentesis, bronchoscopy, and mechanical ventilation) blunt trauma Presentation Symptoms sudden-onset, unilateral, pleuritic chest pain dyspnea Physical exam decreased or absent breath sounds hyperresonance on percussion absence of tracheal deviation/JVD (this would imply a tension pneumothorax) decreased or absent tactile fremitus IMAGING Diagnostic testing chest radiograph best initial test will show collapsed lung (lack of pulmonary markings extending to periphery) computed tomography (CT) of the chest most accurate test often not indicated but can be ordered if clinical suspicion with a normal appearing chest radiograph can further elucidate other injuries (rib fractures) ultrasound will demonstrate an absence of lung sliding Differential Primary spontaneous pneumothorax Secondary spontaneous pneumothorax Tension pneumothorax distinguishing factor tension physiology present (hypotension, tachycardia, JVD, and poor O2 saturation) can be associated with procedures such as central line placement Panic attack distinguishing factor only sinus tachycardia without other organic etiologies of symptoms Treatment Management approach always start with the ABC's of trauma prior to diagnostic testing Small pneumothorax, stable vitals, and asymptomatic patient 100% oxygen and observation the pneumothorax will resorb Large pneumothorax and symptomatic patient aspiration (needle thoracocentesis) chest tube/pigtail catheter indications lower threshold to place chest tube if a secondary pneumothorax can be primary treatment or if needle aspiration fails Recurrent pneumothorax video-assisted thoracoscopic surgery pleurodesis injection of an irritant into pleural space scars pleural layers together Complications Recurrence Bilateral pneumothoraces can cause hemodynamic instability May progress to a tension pneumothorax