Spontaneous Pneumothorax

Spontaneous pneumothorax is air entering the pleural space without trauma. Primary spontaneous pneumothorax (PSP) typically affects tall, thin males aged 18-40 who smoke; subpleural apical blebs and bullae rupture during pressure changes. Secondary spontaneous pneumothorax (SSP) occurs in patients with underlying lung disease (COPD, cystic fibrosis, lung cancer, pulmonary fibrosis, lymphangioleiomyomatosis, Pneumocystis jirovecii pneumonia) and carries higher morbidity and mortality.

Patients describe sudden ipsilateral pleuritic chest pain and dyspnea; large pneumothoraces produce hypoxia, tachypnea, hyperresonant percussion, and absent breath sounds. Tension pneumothorax (mediastinal shift, tracheal deviation, hemodynamic compromise) is a clinical diagnosis requiring immediate decompression. Diagnostic studies include upright chest radiograph (visceral pleural line), CT for small or recurrent cases, and ultrasound (loss of lung sliding, lung point) in trauma or critical care.

Management depends on size, symptoms, and underlying disease. Small PSP (<2 cm at hilum) without symptoms can be observed with high-flow oxygen to accelerate resorption. Larger PSP can be aspirated or managed with small-bore chest tube (8-14 Fr). SSP usually requires chest tube drainage. Persistent air leak beyond 4-5 days, recurrence, or bilateral disease prompts video-assisted thoracoscopic surgery (VATS) with bullectomy and mechanical or chemical pleurodesis. Recurrence rates are 30-50% after first PSP without surgery and <5% after VATS pleurodesis. Smoking cessation reduces recurrence.