Orientation notes for study. Check current BTS or local guidelines and follow your hospital protocol.
Definition
A pneumothorax is air in the pleural space, which allows the lung to collapse away from the chest wall.
Types and causes
| Type | Cause |
|---|---|
| Primary spontaneous | No underlying lung disease: tall, thin young men, smokers, rupture of subpleural blebs |
| Secondary spontaneous | Underlying lung disease: COPD (commonest), TB, PCP (HIV), cystic fibrosis, asthma, lung cancer, ILD, Marfan syndrome, catamenial (menstrual) |
| Traumatic | Penetrating or blunt chest injury, rib fracture |
| Iatrogenic | Central line insertion, lung biopsy, pleural aspiration, mechanical ventilation (barotrauma) |
| Tension | One-way valve: air enters but cannot leave, pressure builds (see below) |
Clinical features
- Symptoms: sudden-onset pleuritic chest pain (often unilateral) and breathlessness; may be minimal in a small primary pneumothorax; more severe in secondary pneumothorax.
- Signs: reduced chest expansion, hyper-resonant percussion, reduced or absent breath sounds and reduced vocal resonance on the affected side.
- Tension pneumothorax (a clinical emergency): severe respiratory distress, tachycardia, hypotension, distended neck veins, tracheal deviation AWAY from the affected side, cyanosis, hyper-resonant hemithorax with absent breath sounds. Do not wait for an X-ray.
Investigations
- Erect PA chest X-ray: a visible lung edge with absent lung markings beyond it. In tension, the mediastinum is shifted and the diaphragm is flattened.
- Size (BTS): large if a rim of 2 cm or more between the lung edge and chest wall at the level of the hilum; small if below 2 cm.
- Ultrasound (absent lung sliding) and CT if unclear (blebs, underlying disease).
- ABG or oximetry if the patient is breathless.
Management
Tension pneumothorax: immediate needle decompression (large-bore cannula, 2nd intercostal space mid-clavicular line or 4th–5th space anterior axillary line), then a chest drain. Give high-flow oxygen.
Primary spontaneous (BTS approach):
- Small and not breathless: observe (and review as an outpatient); oxygen if needed.
- Large or breathless: needle aspiration (16–18G cannula, up to 2.5 L); if it fails, a small-bore chest drain.
Secondary spontaneous:
- Large (2 cm or more) or breathless: chest drain (admit).
- 1–2 cm: needle aspiration, admit and observe.
- Under 1 cm: high-flow oxygen and observe, admitted.
Chest drain care: insert in the "safe triangle" (above the 5th intercostal space, anterior to the mid-axillary line, behind the lateral border of pectoralis major); connect to an underwater seal; bubbling means an air leak, swinging shows the drain is in the pleural space; never clamp a bubbling drain; remove when the lung is up and the leak has stopped.
Persistent air leak or recurrence: surgery (VATS bullectomy and pleurectomy or pleurodesis).
Advice at discharge: stop smoking (reduces recurrence); do not fly until the X-ray has cleared and for 1 week after resolution; never scuba dive unless definitive surgery has been performed.
Complications
- Tension pneumothorax and cardiac arrest, persistent air leak (bronchopleural fistula), re-expansion pulmonary oedema, infection (empyema), recurrence (about 30% after a first primary episode), haemopneumothorax, surgical emphysema.
Exam points
- Tension pneumothorax is a clinical diagnosis: treat first.
- Hyper-resonant percussion + absent breath sounds = pneumothorax.
- 2 cm rim is the cut-off for "large".
- COPD, TB and PCP cause secondary pneumothorax: a pneumothorax is more dangerous in lung disease.
- Advice about flying and diving.
Pharmacology at a glance
Tap a drug name for its full card (how it works, adverse effects, cautions, dose), then use Back to this note to return to this spot.
| Drug | Class | Role here | Watch for |
|---|---|---|---|
| Paracetamol | Analgesic | First-line for pleuritic pain | Liver injury in overdose |
| Ibuprofen | NSAID | Added for pain if no contraindication | Stomach irritation, kidney injury |
| Morphine | Opioid analgesic | Severe pain, for example with a chest drain | Drowsiness, respiratory depression, constipation |
Oxygen speeds reabsorption of air in a small pneumothorax. Local anaesthetic is used for the chest drain site, and the key treatment is mechanical: aspiration or a drain.
Practice questions
1. A 22-year-old tall, thin smoker has sudden pleuritic chest pain and mild breathlessness. Chest X-ray: 1 cm rim of air; he is comfortable. Best management: A. Chest drain · B. Observation with outpatient review · C. Pleurodesis · D. Thoracotomy · E. Needle decompression Answer: B.
2. A man after a road traffic crash has severe dyspnoea, BP 80/50, distended neck veins, absent breath sounds on the right and tracheal deviation to the left. Immediate management: A. Chest X-ray · B. CT chest · C. Needle decompression · D. Intubation first · E. IV antibiotics Answer: C.
3. A man with COPD has a 3 cm pneumothorax and is breathless. Best management: A. Observation · B. Chest drain · C. Discharge · D. Needle decompression only · E. Steroids Answer: B. Secondary pneumothorax with breathlessness.