pneumothoraces

Pneumothoraces are accumulations of air in the pleural space, causing partial or complete collapse of the lung. They are commonly categorized as spontaneous (primary or secondary), traumatic, or iatrogenic. Tension pneumothorax is a life-threatening subtype in which trapped air increases pleural pressure and hampers cardiopulmonary function.

Primary spontaneous pneumothorax (PSP) occurs in individuals without known lung disease, often tall, thin young men, and may be associated with smoking. Secondary spontaneous pneumothorax arises with underlying lung disease such as chronic obstructive pulmonary disease, asthma, cystic fibrosis, or interstitial lung disease. Traumatic pneumothorax follows chest injury, while iatrogenic pneumothorax results from medical procedures such as central venous catheterization, thoracentesis, or lung biopsy.

Pathophysiology involves air entering the pleural space, disrupting the negative intrapleural pressure and allowing the lung to collapse. In tension pneumothorax, air enters but cannot escape, progressively compressing the lung and shifting the mediastinum, which can reduce venous return and cardiac output.

Clinical features depend on size and type. PSP and other non-tension pneumothoraces often present with sudden unilateral chest pain and dyspnea, with decreased or absent breath sounds and hyperresonance on the affected side. Tension pneumothorax can cause hypotension, tachycardia, neck vein distension, and, if severe, tracheal deviation.

Diagnosis typically involves chest radiography, with ultrasound and CT as adjuncts. Management depends on stability and size. Small, stable PSP may be observed with supplemental oxygen; larger or symptomatic PSP often requires needle aspiration or chest tube drainage. Tension pneumothorax requires immediate needle decompression, followed by chest tube placement. Traumatic and iatrogenic pneumothoraces generally require chest tube treatment and management of the underlying cause. Recurrence is common in PSP, and preventive options include smoking cessation and, for recurrent cases, pleurodesis or surgical interventions. Complications can include re-expansion edema and persistent air leak.