Spontaneous Pneumothorax

⚠️ Treatment depends critically on whether it is a primary or secondary pneumothorax. Underlying lung disease = secondary, which is treated far more cautiously. 💨 Always suspect a pneumothorax in any mechanically ventilated patient with sudden deterioration (may present only as ↑ resistance to ventilation).

📖 About

• 🫁 Spontaneous presence of air in the pleural space.
• 👵 Patients >50 or with lung disease = secondary pneumothorax → require admission.

⚙️ Mechanism

• Hole in visceral pleura → air leaks into pleural space.
• Penetrating wounds (oesophagus, mediastinum, diaphragm).
• Gas-forming bacteria within empyema.

📂 Types

• 🟢 Primary: Age <50, no lung disease, minimal smoking history.
• 🔴 Secondary: Due to underlying lung disease.
• ⚔️ Traumatic: Injury-related (penetrating/blunt).

📊 Classification

• Primary Pneumothorax:
  • 👨 Tall, thin young men (20–40 yrs), often right-sided.
  • 🚬 Smoking ↑ risk (even subclinical lung disease).
  • 🌬️ Subpleural blebs rupture due to apex stress.
  • 🔁 Recurrence: ~40% within 2 years (especially smokers).
• Secondary Pneumothorax:
  • Due to 👇
    • ⚔️ Trauma (penetrating injuries).
    • 💉 Iatrogenic (biopsy, pleural procedures).
    • 💨 Ventilation (barotrauma with high PEEP).
    • 🫁 Lung disease (COPD, asthma, CF, PCP pneumonia).
    • 📉 Rare: Marfan’s, catamenial (endometriosis).

🩺 Clinical

• May be silent if small.
• Typical: sudden chest pain ⚡ + breathlessness 🫁.
• Severe: hypotension, tachycardia, cyanosis.
• Exam: hyper-resonance, ↓ breath sounds. ➡️ Tension PTX: tracheal deviation + distended neck veins.

🔍 Investigations

• 📸 CXR: Lung edge visible, no markings peripheral to it.
• 📏 Size: Small = <2 cm rim; Large = >2 cm.
• 🖥️ HRCT: For complex cases / to differentiate bullae.

💊 Management of Spontaneous Pneumothorax

• Initial assessment: ABCDE assessment, observations, oxygen saturation, analgesia and chest X-ray. Give oxygen if hypoxic; use controlled oxygen in patients at risk of CO₂ retention, such as severe COPD. If tension pneumothorax is suspected clinically, treat immediately — do not wait for imaging. Assess: symptoms, haemodynamic stability, oxygen requirement, underlying lung disease, pneumothorax size and recurrence risk.
• Size terminology: Older BTS guidance used a 2 cm rim on CXR at the level of the hilum to define a large pneumothorax. Current practice is more symptom-led: breathlessness, physiological compromise and underlying lung disease often matter more than size alone. A small pneumothorax is often described as <2 cm; a large pneumothorax as ≥2 cm, but management should not rely on size alone.
• Primary Spontaneous Pneumothorax
  • No underlying lung disease: Minimally symptomatic and physiologically stable: consider conservative management, even if large, with safety-netting and early follow-up.
  • Symptomatic or patient prefers active treatment: consider needle aspiration, ambulatory device or small-bore chest drain depending on local expertise and patient preference.
  • Failed aspiration, persistent symptoms, ongoing air leak or clinical deterioration: insert a small-bore chest drain and admit.
• Secondary Spontaneous Pneumothorax — underlying lung disease, e.g. COPD, asthma, cystic fibrosis, ILD:
  • Lower threshold for admission because respiratory reserve is reduced.
  • Small and minimally symptomatic: admit for observation, oxygen if needed, analgesia and repeat imaging.
  • Symptomatic, hypoxic, large or physiological compromise: insert a small-bore chest drain and admit.
  • Needle aspiration may be considered in selected cases, but chest drain is often required.
• Aspiration: Needle aspiration is a controlled procedure for a spontaneous pneumothorax when the patient is usually stable but symptomatic or has a larger pneumothorax. The aim is to aspirate air with a syringe/3-way tap and potentially avoid a chest drain. Site is 2nd ICS MCL, or 4th/5th ICS AAL or MAL, aspirate up to 2.5 L → repeat CXR.
• Chest drain: Use a small-bore drain in most spontaneous pneumothoraces. Large-bore drains are usually reserved for trauma, haemothorax, very large air leak or specialist indications. Avoid routine suction initially; consider specialist advice if the lung fails to re-expand or there is persistent air leak. Indications: >2 cm and symptoms, failed aspiration, secondary PTX. Insert in safe triangle → monitor bubbling & swinging.
• When to involve thoracic surgery / consider VATS:
  • Persistent air leak, often after 5–7 days depending on local policy and clinical context.
  • Failure of lung re-expansion despite chest drainage.
  • Recurrent ipsilateral pneumothorax.
  • First contralateral pneumothorax.
  • Bilateral spontaneous pneumothoraces.
  • Spontaneous haemopneumothorax.
  • High-risk occupation or activity, e.g. pilot, diver, remote worker.
  • Patient preference after discussion of recurrence risk and treatment options.
• VATS procedure: VATS = video-assisted thoracoscopic surgery. Usually involves stapling/resection of visible blebs or bullae plus pleurodesis or pleural abrasion/pleurectomy to reduce recurrence. It is used mainly for recurrence prevention or persistent air leak, not as routine first-line treatment for every first pneumothorax.
• Discharge advice:
  • Provide clear return precautions: worsening breathlessness, chest pain, syncope or collapse.
  • Arrange follow-up chest imaging according to local pleural pathway.
  • Avoid air travel until radiological resolution and specialist advice.
  • Advise smoking cessation, as smoking significantly increases recurrence risk.
  • Do not scuba dive after spontaneous pneumothorax unless definitively treated and cleared by a specialist diving medicine service.

🚨 Tension Pneumothorax:

• Emergency! Needle decompression → chest tube. Signs: severe distress, deviated trachea, distended neck veins, hypotension.
• Needle Decompression of Tension PTX Do not wait for imaging if the patient is unstable. Modern trauma teaching often uses 4th or 5th ICS, just anterior to the mid-axillary line. This is around the level of the nipple in males / inframammary fold area, but always count ribs if possible. Alternative is 2nd ICS mid-clavicular line, but failure rates can be higher because the chest wall is thicker and landmarking is often poor. Current sources describe both sites, with 4th/5th ICS anterior-to-mid-axillary or mid-axillary region increasingly preferred in trauma algorithms. Use a long large-bore cannula, often 14G/10–14G depending on local kit. Insert perpendicular to chest wall, just above the rib. Advance until air escapes / “hiss” is heard. Advance catheter over needle into pleural space. Remove needle, leave cannula in place.

Landmarks

⚠️ Complications

• 💨 Persistent air leak → may need thoracic surgery.
• 🦠 Infection (chest drain in situ).
• 🔁 Recurrence (esp. smokers, tall males).

📚 References

• BTS Pleural Disease Guideline (2010)
• NHS: Spontaneous Pneumothorax Guidelines