Pneumothorax - NAC OSCE Canada Quick Reference
Definition & Classification
Pneumothorax is air in the pleural space, classified as primary spontaneous (PSP - no underlying lung disease), secondary spontaneous (SSP - underlying lung disease), or traumatic.
Key Distinctions:
- Primary: Typically young, tall, thin males; often from apical blebs
- Secondary: COPD, asthma, CF, HIV/PCP, interstitial lung disease
- Tension: Medical emergency with hemodynamic compromise
Clinical Presentation
Look for:
- Sudden onset pleuritic chest pain
- Dyspnea (severity guides management, NOT size)
- Decreased breath sounds on affected side
- Hyperresonance to percussion
- Tracheal deviation (tension pneumothorax only)
- Hypotension, tachycardia, JVD (tension)
Critical pitfall: In SSP, even small pneumothoraces can cause severe symptoms due to limited respiratory reserve 1.
Diagnosis
Physical exam + imaging:
- CXR: Standard, measure size (>2cm from chest wall = large)
- Ultrasound: Absence of lung sliding, no B-lines, lung point sign
- CT: Most sensitive, use for occult/traumatic cases
Management Algorithm
Tension Pneumothorax (Unstable Patient)
Immediate needle decompression → 2nd intercostal space, midclavicular line OR 5th intercostal space, anterior axillary line → followed by chest tube 2
Primary Spontaneous Pneumothorax (Stable)
For minimally symptomatic, clinically stable patients: Conservative observation is recommended 3. This represents a paradigm shift from routine intervention.
If intervention needed:
First-line: Needle aspiration (strongly recommended over chest tube) 3
- Success rate 84-97% with small catheters (7-9F)
- Shorter hospital stay than chest tubes
- Observe for clinical stability before discharge 1
If aspiration fails: Small-bore chest tube (10-14F) 1
NO routine suction initially - only add after 48 hours for persistent air leak 1
Secondary Spontaneous Pneumothorax
Lower threshold for intervention due to poor respiratory reserve:
- Admit for 24 hours even after successful aspiration 1
- Small-bore chest tube (10-14F) often needed
- Refer to respiratory specialist if not resolved in 48 hours 1
Persistent Air Leak
Definition: Continued bubbling through chest tube at 48 hours 1
Management:
- Add suction (-10 to -20 cm H₂O) after 48 hours 1
- Refer to respiratory physician
- Consider surgical opinion at 3-5 days (not evidence-based, but practical) 1, 4
- Most resolve by 14 days without surgery 1
Surgical Indications
Refer for thoracic surgery consultation for 1, 4:
- Second ipsilateral pneumothorax
- First contralateral pneumothorax
- Bilateral pneumothorax
- Persistent air leak >5-7 days
- Spontaneous hemothorax
- High-risk professions (pilots, divers) - even after first episode
- Pregnancy
- Patient preference for reduced recurrence risk
Surgical approach:
- VATS preferred for general cases (less pain, shorter stay) 4
- Open thoracotomy for high-risk occupations requiring lowest recurrence rate 4
- Pleurectomy has lowest recurrence (0.4%) vs pleural abrasion (2.3%) 1
Special Populations
HIV/AIDS with PCP
- 40% bilateral, prolonged air leaks, high mortality
- Treat underlying PCP infection
- Early aggressive management 1
Cystic Fibrosis
- Early aggressive treatment required
- Consider surgery after first episode if fit 1
- Pleurectomy preferred (95% success)
Discharge & Follow-up
Critical counseling points:
- No air travel until CXR confirms resolution 1
- Permanent diving prohibition (unless bilateral surgical pleurectomy) 1
- Follow-up CXR at 2 weeks for conservatively managed cases 1
- Return immediately if worsening dyspnea
Recurrence risk:
- PSP: ~30% after first episode, ~50% after second
- SSP: Higher recurrence, worse outcomes
OSCE Pearls
Don't miss:
- Symptoms guide management, not pneumothorax size 5, 6
- Tension pneumothorax = clinical diagnosis, don't wait for imaging
- SSP patients need admission even after successful aspiration
- Counsel about diving (absolute contraindication) and flying restrictions
- Small-bore tubes (10-14F) are as effective as large-bore 1