Needle aspiration and decompression of a pneumothorax

What it is

Two different procedures share this page. Needle aspiration treats a stable spontaneous pneumothorax: a cannula is placed in the pleural space, air is drawn off with a syringe and three-way tap, and the lung is allowed to re-expand. It suits a symptomatic primary spontaneous pneumothorax (no known lung disease) and spares many patients a chest drain; small, minimally symptomatic ones may just be observed, and current guidelines weigh symptoms more than size. Secondary pneumothorax (in COPD or other lung disease) is less forgiving and more often needs a drain and admission. Needle decompression treats a tension pneumothorax, a clinical emergency in which air trapped under pressure pushes the mediastinum across, kinks the great veins and stops venous return. The diagnosis is made at the bedside and treatment is not delayed for an X-ray. A long large-bore cannula is placed in the 4th or 5th intercostal space just in front of the mid-axillary line in adults, where the chest wall is thinner, or in the 2nd intercostal space in the mid-clavicular line, the classic site still used in children. Decompression only buys time: a chest drain always follows.

Indications

• Tension pneumothorax: emergency decompression, in trauma, during ventilation or spontaneously.
• Symptomatic primary spontaneous pneumothorax in a stable patient: needle aspiration.
• Selected small secondary pneumothorax in a stable patient, with admission and close observation.
• Iatrogenic pneumothorax (after a line or pleural procedure) that is symptomatic but stable.
• Cardiac arrest with suspected tension pneumothorax as a reversible cause.

Contraindications and precautions

• No delay for tests when tension is suspected: the risk of not decompressing is greater.
• Do not aspirate a large bulla mistaken for a pneumothorax: CT if the X-ray is unclear in emphysema.
• Ventilated patients and large secondary pneumothoraces: a drain rather than aspiration.
• Haemopneumothorax or trauma with blood in the chest: a large-bore drain is needed.
• Coagulopathy and skin infection at the site are relative concerns; in tension, decompress anyway.

Equipment

• Oxygen at high concentration and monitoring (pulse oximetry, ECG, blood pressure).
• Long large-bore intravenous cannula (for example 14 G) for decompression.
• For aspiration: a cannula (16 to 18 G), three-way tap, large syringe and extension tubing.
• Antiseptic, sterile gloves, drape, local anaesthetic for elective aspiration, and dressing.
• Chest drain set ready, because decompression and failed aspiration both lead to one.

Step by step (and why)

1. Give high-flow oxygen and assess; in tension, act now — the patient can arrest within minutes.
2. Choose the site: 4th–5th space anterior to the mid-axillary line, or 2nd space mid-clavicular — avoid medial vessels.
3. Clean the skin quickly (and anaesthetise if stable) — sterility still matters, but never delays a tension decompression.
4. Insert the cannula just over the upper border of the rib, perpendicular to the skin — this avoids the vessels under each rib.
5. In tension, listen for a hiss, withdraw the needle and leave the cannula — release of air shows the diagnosis was right.
6. For aspiration, connect the three-way tap and draw off air with the syringe — the lung re-expands as air leaves.
7. Stop aspiration at resistance, coughing or the protocol limit — resistance suggests the lung is up or the cannula kinked.
8. Repeat the chest X-ray — it shows whether the lung has re-expanded and guides the next step.
9. After decompression, insert a chest drain — the cannula is a temporary vent that blocks or dislodges.

Complications

• Failure: the cannula is too short for the chest wall, kinks or blocks, and tension returns.
• Lung laceration or new pneumothorax when no tension was present.
• Bleeding from intercostal or internal thoracic vessels, especially if placed too low on the rib or too medially.
• Infection at the site or in the pleural space.
• Recurrence of spontaneous pneumothorax, especially in smokers and in secondary disease.

Next step

• After decompression, insert a chest drain and get a chest X-ray; call a senior immediately for any tension pneumothorax.
• Successful aspiration (lung re-expanded, patient comfortable): discharge with written advice and early clinic review.
• Failed aspiration, a secondary pneumothorax or a deteriorating patient: chest drain and admission.
• Advise stopping smoking, no flying until resolution is confirmed, and no diving unless definitive surgery is done.
• Recurrent or persistent pneumothorax: refer to thoracic surgery for definitive treatment.

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Elsewhere in DurgiPedia

• Pneumothorax on the chest X-ray
• Pneumothorax syndrome
• Respiratory distress and respiratory failure: the signs

Connections

← All clinical skills

Educational content; it does not replace supervised hands-on training, your institution's protocols or a prescriber's order. A procedure is learnt with a teacher and done only once you are trained to do it.

Sources: Acute Pneumothorax Evaluation and Treatment (StatPearls (NCBI Bookshelf), 2025); Tension Pneumothorax (StatPearls (NCBI Bookshelf), 2025).

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Representative model, for educational purposes only.