What is pneumothorax?

Pneumothorax: Definition, Types, and Management

Pneumothorax is defined as the abnormal presence of air in the pleural space between the lung and chest wall, resulting in partial or complete lung collapse. 1 This condition can cause significant respiratory compromise and requires prompt assessment and appropriate management to prevent morbidity and mortality.

Types of Pneumothorax

Primary Spontaneous Pneumothorax (PSP)

• Occurs in otherwise healthy people without clinically apparent underlying lung disease 1
• Most common in young adults, with reported incidence of 18-28/100,000 per year for men and 1.2-6/100,000 per year for women 1
• Despite absence of clinical lung disease, subpleural blebs and bullae are found in up to 90% of cases at thoracoscopy 1
• Strong association with smoking: lifetime risk in healthy smoking men may be as high as 12% compared to 0.1% in non-smoking men 1

Secondary Spontaneous Pneumothorax (SSP)

• Occurs in patients with underlying lung disease (commonly COPD) 1
• Higher risk of morbidity and mortality than PSP 1
• Patients may be classified as having SSP if they are older than 50 years with a smoking history 1

Tension Pneumothorax

• Life-threatening emergency where intrapleural pressure exceeds atmospheric pressure throughout inspiration and expiration 1
• Results from a one-way valve mechanism drawing air into the pleural space during inspiration but not allowing it out during expiration 1
• Characterized by rapid deterioration with labored respiration, cyanosis, sweating, tachycardia, and hemodynamic compromise 1
• Requires immediate decompression 1

Iatrogenic Pneumothorax

• Caused by medical procedures such as transthoracic needle aspiration (24%), subclavian vessel puncture (22%), thoracocentesis (22%), pleural biopsy (8%), and mechanical ventilation (7%) 1

Clinical Presentation

Symptoms

• Chest pain
• Shortness of breath
• In severe cases: respiratory distress, hypoxemia
• Tension pneumothorax: rapid deterioration with distress, cyanosis, sweating, tachycardia 1

Clinical Stability Assessment

• Stable patient: respiratory rate <24 breaths/min, heart rate 60-120 beats/min, normal BP, room air O₂ saturation >90%, ability to speak in whole sentences between breaths 2
• Unstable patient: any patient not fulfilling the above criteria 1

Diagnosis

• Chest radiography is the primary diagnostic tool
• Expiratory chest radiographs are not recommended for routine diagnosis of small pneumothorax 1
• CT scanning may be used to identify blebs/bullae and is more sensitive for small pneumothoraces

Management

Tension Pneumothorax (Emergency)

• Immediate decompression with a cannula of adequate length (at least 4.5 cm) inserted into the second intercostal space in the mid-clavicular line 1
• Leave cannula in place until a functioning intercostal tube can be positioned 1
• Administer high concentration oxygen 1

Primary Spontaneous Pneumothorax

Small, Asymptomatic PSP

• Observation without intervention 1
• Supplemental oxygen (10 L/min) to increase rate of air reabsorption 2
• Follow-up chest radiograph to confirm resolution 1

Symptomatic or Large PSP

• Simple aspiration as first-line treatment 1
• If aspiration fails or pneumothorax recurs, proceed to intercostal tube drainage 1
• Small-bore catheter (≤14F) or moderate-sized chest tube (16F-22F) attached to either a Heimlich valve or water seal device 1, 2
• Apply suction if the lung fails to re-expand with water seal drainage 1, 2

Secondary Spontaneous Pneumothorax

• More aggressive approach required due to higher risk of complications 1
• Intercostal tube drainage as first-line treatment 1
• Hospitalization recommended for at least 24 hours after successful treatment 1
• Early discussion with respiratory specialist 1

Persistent Air Leak

• If air leak persists beyond 3-4 days, refer for surgical intervention 1, 2
• Video-assisted thoracoscopic surgery (VATS) is the preferred approach 2
• Surgical options include identification and stapling of air leaks, pleurodesis, or pleurectomy 2

Prevention of Recurrence

• For PSP: consider preventive measures after recurrence 2
• For SSP: consider preventive measures after first occurrence 2
• Surgical approach (preferred): VATS with staple bullectomy and pleural symphysis 2
• Chemical pleurodesis: consider for patients with contraindications to surgery 2
• Strongly emphasize smoking cessation to reduce recurrence risk 1

Post-Treatment Considerations

• Remove chest tube 24 hours after full re-expansion and cessation of air leak 1
• Avoid air travel until chest radiograph confirms complete resolution 1
• Diving should be permanently avoided after a pneumothorax unless the patient has had bilateral surgical pleurectomy 1
• Arrange follow-up in chest clinic within 7-10 days 1

Special Considerations

Cystic Fibrosis Patients

• Higher risk of contralateral pneumothoraces (up to 40% of patients) 1
• Early and aggressive treatment recommended 1
• Consider surgical intervention after first episode if patient is fit for procedure 1
• Partial pleurectomy has 95% success rate with minimal reduction in pulmonary function 1

Outpatient Management

• Selected stable patients with PSP may be managed as outpatients with small-bore catheter and Heimlich valve 1, 3
• Patient compliance, cognition, support, and housing situation must be verified 3
• Follow-up should be arranged within 2 days 1

By understanding the pathophysiology, presentation, and management options for pneumothorax, clinicians can provide prompt and appropriate care to minimize morbidity and mortality in affected patients.