Tension means decompress now, X-ray later. Otherwise, decide on the X-ray and the symptoms: primary or secondary, breathless or not, and treat with observation, aspiration or a drain.
A tall, thin 21-year-old student felt a sudden sharp pain on the left side of his chest while sitting in class. He is a little breathless. Pulse 96, SpO₂ 97%, BP normal. Breath sounds are reduced on the left. The X-ray shows a 3 cm rim of air at the left side.
Check every dose against a current drug reference and your hospital protocol.
On this page
What it is
Air enters the space between the lung and the chest wall, and the lung collapses away from the wall.
Primary spontaneous: no known lung disease, typically tall, thin young men, smokers.
Secondary: underlying lung disease: COPD, old TB (common in Pakistan), asthma, cystic lung disease. Less lung reserve, so small pneumothoraces are dangerous.
Traumatic or iatrogenic: injuries, central lines, pleural taps, ventilation.
Tension pneumothorax
Decompress first, X-ray later
Signs: severe breathlessness, falling SpO₂, low BP, fast pulse, distended neck veins, absent breath sounds on one side, trachea pushed to the other side (late sign). In a ventilated patient: rising airway pressures and falling BP.
Action: high-flow oxygen, then needle (or finger) decompression on the affected side straight away:
Site: 4th or 5th intercostal space, just in front of the mid-axillary line (the 2nd intercostal space in the mid-clavicular line is an alternative, but the chest wall is often too thick there).
Then insert a chest drain.
Primary or secondary?
Choose the approach (BTS 2023)
Primary or secondary?
Primary, minimal symptoms
Conservative care is often possible, even if the pneumothorax is not small
Observe, repeat X-ray, clear follow-up and return advice
Primary, symptomatic
Needle aspiration, an ambulatory device, or a chest drain
Choice depends on the patient and local practice
Secondary
Admit to hospital
Usually a chest drain if breathless or larger than a thin rim
Senior and respiratory review
Senior’s tip
Treat the patient, not the X-ray. A large primary pneumothorax in a comfortable young man can often be watched. A small secondary pneumothorax in a breathless COPD patient can be life-threatening.
Chest drain essentials
Before and during insertion
Consent and seniorSomeone trained, ideally with ultrasound.
Check the sideX-ray and examination. Mark the site.
Safe triangleFront: edge of pectoralis major. Back: edge of latissimus dorsi. Bottom: 5th intercostal space (about nipple level). Apex: below the armpit.
Local anaestheticLidocaine 1%, up to 3 mg/kg. Infiltrate skin, muscle and pleura. Aspirate air to confirm the site.
Insert above the ribThe nerve and vessels run under each rib.
Connect to an underwater sealBelow the patient, never clamped (unless advised), check it bubbles and swings.
Bubbling means air is still leaking. Swinging with breathing means the drain is in the pleural space.
No bubbling and the lung is up on X-ray: the drain can usually be removed (senior decision).
Never clamp a bubbling drain. It can cause tension.
Persistent air leak after a few days: respiratory or thoracic surgical review.
Before discharge
Return immediately if breathless or chest pain returns.
Stop smoking: it greatly increases the chance of another pneumothorax.
Flying: avoid until the pneumothorax has fully resolved on X-ray (and for a period after, as advised).
Diving: avoid for life unless the cause has been treated surgically.
Follow-up X-ray and clinic review.
Common mistakes
Avoid these
Waiting for an X-ray in a patient with tension.
Deciding on a drain by the size alone.
Treating a secondary pneumothorax in a COPD patient like a primary one.
Mistaking a large bulla for a pneumothorax (CT if unsure, before inserting a drain).
Clamping a bubbling drain.
Frequently asked questions
Where is needle decompression done for tension pneumothorax?
In adults, the 4th or 5th intercostal space just in front of the mid-axillary line on the affected side, followed by a chest drain. The 2nd intercostal space in the mid-clavicular line is an alternative.
Does every pneumothorax need a chest drain?
No. Many primary pneumothoraces with few symptoms can be managed conservatively. Secondary pneumothoraces usually need admission and often a drain.
Where is the safe triangle for a chest drain?
Bounded by the edge of pectoralis major in front, the edge of latissimus dorsi behind, and the 5th intercostal space below, with the apex below the armpit.
Test yourself
Exam-style questions on this guide, from our two question banks. Choose an answer to see why each option is right or wrong.
NRE-1 PrepClinical MCQs, PMDC NRE style
1. After a central line, a patient becomes suddenly breathless with BP 80/50, distended neck veins and absent breath sounds on the right. What is the immediate step?
Answer: Decompress the right chest. Tension pneumothorax: decompress immediately, then insert a chest drain.
Chest X-ray first: Tension pneumothorax is a clinical diagnosis.
CT chest: Delay is fatal.
IV fluids and observe: Doesn't treat the cause.
Intubate: May worsen tension.
2. A COPD patient has a 1.5 cm pneumothorax with SpO₂ 86%. What is the best plan?
Answer: Admit and insert a chest drain. Secondary pneumothorax in lung disease is poorly tolerated even when small. Admit, oxygen and usually a chest drain.
Pleurodesis today: Not first line.
Discharge with follow-up: Secondary pneumothorax is high risk.
Aspiration and discharge same day: Not appropriate for symptomatic secondary pneumothorax.
Observation only, no admission: Not with hypoxia.
3. A comfortable 21-year-old has a 3 cm primary spontaneous pneumothorax and SpO₂ 97%. What is true?
Answer: Conservative care or aspiration. Stable primary spontaneous pneumothorax can often be managed conservatively or with aspiration, with clear follow-up.
No follow-up needed: Follow-up is needed.
A large-bore chest drain is mandatory: Not for a stable primary pneumothorax.
Immediate surgery: Not indicated.
He can fly tomorrow: Flying is avoided until resolution.
4. A tall thin 22-year-old smoker has sudden pleuritic chest pain and mild breathlessness. Chest X-ray shows a 3 cm rim (at hilum) right pneumothorax. He is stable, SpO₂ 96%. What is appropriate?
Answer: Needle aspiration. Primary spontaneous pneumothorax (no lung disease; tall thin young men, smokers): small/minimally symptomatic → conservative observation with follow-up; large/symptomatic → needle aspiration or ambulatory drain; chest drain if aspiration fails. Advise smoking cessation; no flying until resolved; no diving ever unless surgery. Recurrent → VATS pleurectomy/pleurodesis. Secondary pneumothorax (COPD) is more dangerous — usually needs a drain and admission.
Immediate thoracotomy: Thoracotomy is not for a first episode.
Bilateral chest drains: Bilateral drains are not indicated.
Talc pleurodesis first-line: Pleurodesis is not first-line.
5. A 22-year-old tall thin man has sudden pleuritic chest pain. Chest X-ray shows a right pneumothorax with a 1.5-cm rim at the hilum. He is not breathless and saturations are 98%. What is the management?
Answer: Conservative care, follow-up. Primary spontaneous pneumothorax with minimal symptoms can be managed conservatively with follow-up and a repeat X-ray. Significant symptoms → needle aspiration or chest drain. Secondary pneumothorax (lung disease, older smokers) usually needs admission and drainage. Tension needs immediate decompression. Advise no flying until resolved and avoid scuba diving unless definitive surgery is done.
Chest drain: A chest drain is not needed for a small primary pneumothorax with no breathlessness.
Needle aspiration: Needle aspiration is for symptomatic primary pneumothorax; he has no breathlessness.
Needle decompression, then drain: Needle decompression is for tension pneumothorax with haemodynamic compromise.
FCPS-1 PrepBasic science MCQs for CPSP FCPS Part 1
6. During thoracocentesis, where should the needle be inserted to avoid the intercostal vessels and nerve?
Answer: Just above the lower rib. The intercostal vein, artery and nerve (VAN, from above down) run in the costal groove on the lower border of each rib. Inserting the needle just above the upper border of the rib below avoids them. Collateral branches run along the upper border of the lower rib but are small.
Just below the upper rib: Hits the main neurovascular bundle.
Through the middle of the rib: Not possible.
Along the costal groove: Where the bundle lies.
Anywhere; the bundle runs centrally: The bundle runs at the lower border of each rib.
7. In a pneumothorax, what happens to the lung and the chest wall on that side?
Answer: Lung collapses, chest wall springs out. Normally the lung tends to recoil inwards and the chest wall outwards; negative intrapleural pressure holds them together. When air enters the pleural space, pressure becomes atmospheric, so the lung collapses and the chest wall springs outwards slightly.
Both move inwards: The chest wall's natural tendency is outwards.
