What are the management options for a patient with pneumothorax, considering the size of the pneumothorax, symptoms, and underlying lung disease?

Management of Pneumothorax

For primary spontaneous pneumothorax (PSP) in stable patients, simple aspiration is the recommended first-line treatment and is as effective as chest tube drainage with fewer complications, while secondary spontaneous pneumothorax (SSP) typically requires chest tube drainage except for very small (<1 cm) or isolated apical pneumothoraces in asymptomatic patients. 1

Initial Assessment and Risk Stratification

The first critical step is distinguishing between primary and secondary pneumothorax, as this fundamentally changes management:

• Primary spontaneous pneumothorax (PSP) occurs in otherwise healthy individuals without underlying lung disease, typically young, tall, thin males 2
• Secondary spontaneous pneumothorax (SSP) occurs in patients with known lung disease and is most common in patients over 50 years old 1, 2
• Traumatic pneumothorax (including iatrogenic) requires different management considerations and has higher complication risk 3

Size Classification

• Small pneumothorax: rim between lung margin and chest wall <2 cm 3, 4
• Large pneumothorax: rim >2 cm 3
• For SSP, even smaller thresholds apply: observation alone only for <1 cm depth or isolated apical pneumothoraces 3

Management Algorithm by Type and Size

Primary Spontaneous Pneumothorax (PSP)

For symptomatic patients or large pneumothoraces (>2 cm):

• Simple aspiration is the first-line treatment, which achieves success rates of 59-63% and results in less pain, shorter hospital stays, and lower recurrence rates at 12 months compared to immediate chest tube drainage 1
• Aspirate up to 2.5 liters; if unsuccessful and <2.5 L was aspirated, repeat aspiration is reasonable and succeeds in over one-third of cases 1
• If aspiration fails after removing >2.5 L or symptoms persist, proceed to intercostal tube drainage 1

For small, asymptomatic pneumothoraces:

• Observation with high-flow oxygen (10 L/min) accelerates reabsorption by up to four-fold 3, 4
• A 15% pneumothorax resolves in 8-12 days with room air alone but only 2-3 days with supplemental oxygen 3
• Observe for 3-6 hours with repeat chest radiography to exclude progression 4
• Discharge is appropriate if stable on repeat imaging, with clear instructions to return immediately if breathlessness develops 4

Secondary Spontaneous Pneumothorax (SSP)

SSP requires more aggressive management due to compromised respiratory reserve:

• Intercostal tube drainage is recommended for all SSP except patients who are not breathless and have very small (<1 cm or apical) pneumothoraces 1
• Large secondary pneumothoraces (>2 cm), particularly in patients over 50, are high risk for aspiration failure and should receive chest tube drainage as initial treatment 1
• If simple aspiration is attempted in SSP, admission for at least 24 hours observation is mandatory with prompt progression to tube drainage if needed 1
• Active treatment of the underlying lung disorder is essential 1

Traumatic Pneumothorax

• Hospitalization for observation is recommended due to risk of delayed complications 3
• Simple aspiration is rarely appropriate in traumatic pneumothorax; chest tube drainage is typically required 3
• Monitor closely for pneumothorax progression during the first 48 hours 3
• Higher threshold for intervention compared to PSP due to increased complication risk 3

Chest Tube Management

When chest tube drainage is required:

• Use small calibre tubes (8-14 F) which are as effective as larger tubes with less pain 1
• Do not apply suction immediately after tube insertion 1
• Suction (high volume, low pressure at -10 to -20 cm H₂O) should only be added after 48 hours for persistent air leak or failure to re-expand 1
• Intrapleural local anaesthetic (20-25 ml of 1% lignocaine) given as bolus and every 8 hours significantly reduces pain 1

Referral and Escalation Criteria

Refer to respiratory specialist if:

• Pneumothorax fails to respond within 48 hours to treatment 1
• Persistent air leak exceeding 48 hours duration 1
• Failure of lung to re-expand 1
• Patient requires suction, which should only be managed on specialized lung units 1

Consider earlier surgical referral (2-4 days) for:

• Underlying lung disease with large persistent air leak 1
• Failure of lung to re-expand 1

Critical Monitoring and Follow-up

• Repeat chest radiography after 3-6 hours for observed pneumothoraces to document stability or progression 4
• Most significant pneumothoraces are detected on chest radiograph 1 hour after the procedure, though occasional delayed pneumothoraces occur beyond 24 hours 1
• Follow-up within 12-24 hours with repeat imaging to document resolution for discharged patients 4
• Patients should not travel by air within 6 weeks of pneumothorax resolution 1

Common Pitfalls to Avoid

• Applying suction too early after chest tube insertion, particularly in primary pneumothorax present for several days, may precipitate re-expansion pulmonary oedema 1
• Underestimating pneumothorax size on plain chest radiographs; lateral or lateral decubitus views may be helpful if diagnosis unclear 4
• Managing SSP as conservatively as PSP; secondary pneumothoraces require lower thresholds for intervention 1
• Discharging patients without clear safety-net instructions to return immediately if breathlessness worsens 4
• Using high pressure systems for suction, which can lead to air stealing, hypoxaemia, or perpetuation of air leaks 1