pneumothorax

Pneumothorax is the presence of air in the pleural space, the potential space between the visceral and parietal pleura, which can cause partial or complete collapse of the affected lung. Air in the pleural space disrupts the negative intrapleural pressure that keeps the lung expanded and may impair oxygenation.

Pneumothorax is classified by cause as spontaneous (primary or secondary), traumatic, or iatrogenic. Primary spontaneous pneumothorax occurs in people without known lung disease, often due to rupture of subpleural blebs. Secondary spontaneous pneumothorax occurs with underlying lung disease such as COPD, asthma, or cystic fibrosis. Traumatic pneumothorax results from chest injury, while iatrogenic pneumothorax follows medical procedures such as central venous catheterization, lung biopsy, or mechanical ventilation. A tension pneumothorax is a life-threatening form in which air enters the pleural space but cannot escape, leading to progressive mediastinal shift and circulatory compromise.

Clinical presentation typically includes sudden chest pain and shortness of breath. On examination, there may be decreased or absent breath sounds on the affected side, hyperresonance to percussion, and, in tension pneumothorax, signs of hemodynamic instability and tracheal deviation.

Diagnosis is usually made by chest radiograph, with ultrasound offering rapid bedside detection in trauma settings and CT providing detailed assessment when needed.

Management depends on size, stability, and cause. Small, stable primary spontaneous pneumothorax may be observed with supplemental oxygen. Larger or symptomatic pneumothoraces, or secondary pneumothorax, often require needle aspiration or chest tube thoracostomy. Tension pneumothorax requires immediate needle decompression followed by chest tube placement. Recurrence is common; recurrent cases may be treated with pleurodesis or surgical intervention to reduce recurrence risk.