Air in the pleural space
"A pneumothorax ranges from an incidental sliver of air to an immediately fatal tension physiology. The two questions that decide everything are: is it a tension (treat now, image later)? and — for the rest — is the patient symptomatic?"
Summarised from Irwin & Rippe's Intensive Care Medicine; with Marino's The ICU Book, Oh's Intensive Care Manual and BTS.| Type | Setting |
|---|---|
| Primary spontaneous (PSP) | No known lung disease — tall thin young smokers (apical blebs) |
| Secondary spontaneous (SSP) | Underlying lung disease (COPD, asthma, ILD, infection) — less well tolerated |
| Traumatic | Blunt/penetrating chest trauma (± haemothorax) |
| Iatrogenic | Central line, biopsy, positive-pressure ventilation, thoracocentesis |
| Tension | Any of the above with a one-way valve → progressive pressure & collapse |
A clinical diagnosis — do not wait for a CXR
Severe respiratory distress, hypotension, distended neck veins, tracheal deviation away from the side, unilateral absent breath sounds and hyperresonance. In the ventilated patient: sudden rise in airway pressures + hypotension/desaturation.
Immediate needle decompression
Large-bore cannula — 2nd intercostal space mid-clavicular line, or 4th/5th ICS anterior axillary line (often more reliable in adults, per ATLS).
Definitive chest drain
Follow decompression with a formal intercostal chest drain in the safe triangle.
In arrest / peri-arrest trauma
Consider bilateral finger thoracostomies as part of resuscitation.
Confirming and sizing
| Modality | Note |
|---|---|
| Lung ultrasound | Loss of lung sliding, absent B-lines, "lung point" (specific); more sensitive than supine CXR — ideal in the ICU/trauma bay |
| Erect CXR | Visible visceral pleural line, absent lung markings beyond it |
| Supine CXR | Air is anterior/basal — deep sulcus sign; easily missed |
| CT | Gold standard; detects small/loculated/occult pneumothoraces & underlying disease |
Size: BTS measures at the hilum (large if ≥2 cm). But BTS 2023 makes management symptom-driven, not size-driven alone.
The modern, patient-centred approach
| Scenario | Approach |
|---|---|
| Minimal symptoms, no high-risk features | Conservative monitoring can be offered even for a large PSP (spontaneous resolution) |
| Symptomatic, no high-risk features | Choose per patient: needle aspiration, an ambulatory device, or a chest drain |
| High-risk features present | Chest drain and admission |
| Secondary (SSP) | Lower threshold to intervene/admit; small asymptomatic may be observed with O₂ |
| Traumatic | Chest drain (especially if ventilated or haemopneumothorax) |
- Haemodynamic compromise (tension physiology), significant hypoxia, bilateral pneumothorax
- Underlying lung disease, age ≥50 with significant smoking history
- Haemopneumothorax
Insertion & care
- Site: the "safe triangle" — anterior border of latissimus dorsi, lateral border of pectoralis major, above the 5th intercostal space (nipple line), apex below the axilla; always over the rib to avoid the neurovascular bundle.
- Confirm: swinging/bubbling in the underwater seal; CXR for position.
- Suction: not routine; consider low-pressure suction for persistent air leak or non-re-expansion (avoid abrupt high suction — re-expansion pulmonary oedema).
- Removal: when the lung is up and the air leak has stopped (no bubbling), during expiration/Valsalva.
Special ICU concerns
- Any pneumothorax in a ventilated patient can tension rapidly — positive pressure feeds the leak. Have a low threshold to drain, and a high index of suspicion for sudden deterioration (DOPE).
- Persistent air leak (bubbling >3–5 days): reduce airway pressures where possible, exclude drain problems, and involve thoracic surgery (VATS bullectomy/pleurodesis).
- Bronchopleural fistula: consider lung-protective/low-pressure strategies, and surgical/bronchoscopic options.
Common mistakes
Tension is a clinical diagnosis — decompress immediately, image afterwards.
Supine films miss anterior air. Use ultrasound (lung sliding/lung point) or CT.
Low or posterior insertion risks liver/spleen and the neurovascular bundle. Stay in the triangle, over the rib.
Rapid re-expansion can cause re-expansion pulmonary oedema — re-expand gradually.
Positive pressure turns a simple pneumothorax into a tension — drain early.
Exam pearls
Q: How is tension pneumothorax diagnosed and treated?
Clinically (distress, hypotension, distended neck veins, tracheal deviation, absent breath sounds) — immediate needle decompression then chest drain. Never wait for a CXR.
Q: Best bedside test in the ICU/trauma bay?
Lung ultrasound — absent lung sliding and a lung point; more sensitive than supine CXR.
Q: BTS 2023 management principle?
Symptom-based: conservative even for a large PSP if minimal symptoms and no high-risk features; intervene if symptomatic or high-risk.
Q: Where is the safe triangle?
Bordered by latissimus dorsi, pectoralis major and the 5th intercostal space, apex below the axilla — insert over the rib.
Q: PSP vs SSP significance?
SSP (underlying lung disease) is less well tolerated and has a lower threshold for drainage and admission.
All the comparisons in one place
The distinctions that decide urgency and answers — gathered at the end.
Tension vs Simple pneumothorax
| Feature | Tension | Simple |
|---|---|---|
| Physiology | One-way valve, rising pressure | Static air collection |
| Haemodynamics | Shock, distended neck veins | Stable |
| Trachea | Deviated away | Central |
| Action | Decompress NOW (clinical) | Assess, then treat by symptoms |
Primary vs Secondary spontaneous
| Feature | PSP | SSP |
|---|---|---|
| Lung | No underlying disease | COPD/ILD/asthma/infection |
| Typical patient | Tall, thin, young smoker | Older, comorbid |
| Tolerance | Better | Poorer — lower threshold to intervene |
Needle aspiration vs Chest drain
| Feature | Needle aspiration | Chest drain |
|---|---|---|
| Best for | Symptomatic PSP, no high-risk features | High-risk features, SSP, trauma, ventilated |
| Invasiveness | Lower; possible outpatient | Higher; admission |
| Ongoing leak | Not managed | Continuously drained |
References
- Irwin RS, Lilly CM, Mayo PH, Rippe JM (eds). Irwin & Rippe's Intensive Care Medicine. 9th ed. Wolters Kluwer; 2023.
- Marino PL. Marino's The ICU Book. 5th ed. Wolters Kluwer; 2025.
- Bersten AD, Handy JM (eds). Oh's Intensive Care Manual. Elsevier; 2026.
- Roberts ME, Rahman NM, Maskell NA, et al. British Thoracic Society Guideline for pleural disease. Thorax. 2023;78(Suppl 3):s1–s42.
- American College of Surgeons. Advanced Trauma Life Support (ATLS) — thoracic trauma.
- Brown SGA, Ball EL, Perrin K, et al. Conservative versus interventional treatment for spontaneous pneumothorax. N Engl J Med. 2020;382:405–415.