Pneumothorax: Definition, Types, and Management
A pneumothorax is the abnormal collection of air in the pleural space between the lung and chest wall, causing varying degrees of lung collapse that can range from asymptomatic to life-threatening depending on size and underlying lung health. 1
Types of Pneumothorax
- Primary Spontaneous Pneumothorax: Occurs without apparent cause in patients without significant underlying lung disease, typically in tall, thin young adults 1
- Secondary Spontaneous Pneumothorax: Occurs in the presence of existing lung pathology such as COPD, cystic fibrosis, or other pulmonary conditions 1, 2
- Tension Pneumothorax: Life-threatening condition where intrapleural pressure exceeds atmospheric pressure throughout the respiratory cycle, causing mediastinal shift, impaired venous return, and cardiovascular collapse 2
- Iatrogenic Pneumothorax: Results from medical procedures such as transthoracic needle aspiration (24%), subclavian vessel puncture (22%), thoracocentesis (22%), pleural biopsy (8%), and mechanical ventilation (7%) 2
- Traumatic Pneumothorax: Distinct entity resulting from chest trauma 2
- Catamenial Pneumothorax: Occurs in women in association with menstruation, typically right-sided and often associated with pelvic endometriosis 2
Clinical Presentation
- Symptoms: Chest pain, shortness of breath, rapid breathing 3
- Signs: Reduced breath sounds, hyperresonance on percussion, tachycardia 4
- Tension pneumothorax signs: Rapid deterioration, severe respiratory distress, cyanosis, sweating, tachycardia, hypotension, and mediastinal shift 2
Diagnosis
- Chest X-ray: Primary diagnostic tool showing air in the pleural space and varying degrees of lung collapse 3, 4
- CT scan: More sensitive than chest X-ray, particularly useful for small pneumothoraces or complex cases 3
- Classification by size: Can be categorized as partial, complete, or complete with total lung collapse 5
Management
Primary Spontaneous Pneumothorax
- Small, asymptomatic: Observation with follow-up chest X-ray after 2 weeks 2
- Symptomatic or larger: Simple aspiration as first-line treatment (59-83% success rate) 2
- Failed aspiration: Intercostal tube drainage 2
- Recurrent cases: Consider surgical intervention (video-assisted thoracoscopic bullectomy and pleural abrasion) 5
Secondary Spontaneous Pneumothorax
- Small, minimally symptomatic in patients <50 years: Simple aspiration may be attempted (33-67% success rate) 2
- Most cases: Hospitalization and conventional tube drainage recommended 5
- Observation period: Patients successfully treated with aspiration should be admitted for at least 24 hours before discharge 2
Tension Pneumothorax
- Immediate management: High concentration oxygen and prompt insertion of a cannula (at least 4.5 cm long) into the second intercostal space in the mid-clavicular line 2
- Definitive treatment: Intercostal tube drainage after initial decompression 2
Special Situations
- Cystic Fibrosis: Early and aggressive treatment recommended; surgical intervention should be considered after first episode if patient is fit for procedure 2
- Pregnancy: Can be managed by observation if small (<2 cm) without dyspnea or fetal distress; otherwise aspiration or chest tube drainage 2
- Post-treatment precautions: Avoid air travel until chest X-ray confirms resolution; diving should be permanently avoided unless bilateral surgical pleurectomy has been performed 2
Resolution Rate
- Natural reabsorption occurs at approximately 1.25-1.8% of hemithorax volume every 24 hours 2
- A 15% pneumothorax takes approximately 8-12 days to resolve fully 2
- High-flow oxygen therapy can increase reabsorption rate four-fold 2