Skip to textbook content
Doctor’s PassportTextbook
TopicsAll topics

Loading topic navigation…

Textbook navigation
TopicsAll topics

Loading topic navigation…
Educational draft · awaiting clinical reviewUse Rapid for revision, not patient-care decisions. Check current national and local guidance and the BNF or BNFC before acting.

Tension pneumothorax

Respiratory · UK scope · Sources checked 27 Aug 2026 · Clinical review pending

RapidFull
!
Escalate

Tension pneumothorax with haemodynamic instability or severe respiratory compromise is a clinical emergency. Give oxygen, call for resuscitation/trauma support and decompress before imaging. If the first decompression does not restore physiology, check technique/patency and competing or contralateral causes immediately.

Synopsis

Recognise tension physiology clinically and perform immediate chest decompression through the safest available trained route, followed by definitive drainage and treatment of the cause.

  • Tension pneumothorax is pleural air under pressure causing severe respiratory compromise and/or obstructive shock; it is physiology, not simply mediastinal shift on an image.
  • Suspect it after chest trauma, positive-pressure ventilation/NIV, pleural/lung procedure or spontaneous pneumothorax with abrupt hypoxia, hypotension or peri-arrest deterioration.
  • Look for unilateral reduced/absent breath sounds and expansion, hyperresonance, rapidly increasing airway pressures, falling tidal volumes, distended neck veins or surgical emphysema; tracheal deviation is late and unreliable.
  • NICE says decompress before imaging only when haemodynamic instability or severe respiratory compromise is present; in that situation, do not wait for CXR or CT.
  • In hospital, open thoracostomy followed by chest drain is preferred over needle decompression when appropriately trained expertise is available.
  • A trained lateral thoracostomy is made in the 4th or 5th intercostal space just anterior to the mid-axillary line; follow the trauma/pleural procedural standard and protect the neurovascular bundle.
  • If open thoracostomy cannot be delivered immediately, needle thoracostomy with a sufficiently long standard non-valved cannula is a temporary bridge, followed urgently by definitive thoracostomy/chest drain.
  • Never use a blood-control/closed-system IV cannula for needle decompression unless the specific device and required extra equipment are approved for that use; NHS England issued a national safety alert.
  • In traumatic cardiac arrest, trained teams should perform immediate bilateral chest decompression while treating haemorrhage, hypoxia and tamponade; POCUS must not delay this or prolong CPR pauses.
  • After decompression, reassess breath sounds, chest movement, SpO2, BP, airway pressure and clinical response, secure definitive drainage and image only once physiology permits.

    • Key red flags

    Spontaneously breathing patient

    Acute pleuritic pain and severe dyspnoea progressing to unilateral absent breath sounds, hypoxaemia, tachycardia and hypotension; agitation may precede reduced consciousness.

    Ventilated patient

    Abrupt desaturation, hypotension, rising peak airway pressure, reduced delivered tidal volume and unilateral reduced breath sounds; arrest can follow within minutes.

    Traumatic arrest

    Chest trauma with PEA/near-arrest, hypoxia or difficult ventilation: tension is a reversible cause that is treated by immediate bilateral decompression in the trained trauma pathway.

    Procedure-related tension

    Sudden compromise after central line, lung biopsy, thoracentesis, drain removal or positive-pressure initiation should prompt immediate pleural assessment and decompression when unstable.

    Investigation priorities

    01
    Immediate clinical ABCDE assessmentFirst step

    Establish severe respiratory compromise or obstructive shock and choose emergency decompression.

    Management branches

    UnstableDecompress before imaging

    Suspected tension pneumothorax with haemodynamic instability or severe respiratory compromise.

    1. Call resuscitation/trauma and airway help, give high-concentration oxygen, monitor and expose the chest; if on NIV/ventilation, temporarily release positive pressure as clinically safe while immediate decompression is prepared.
    2. Use open thoracostomy in hospital when an appropriately trained operator is immediately available; enter at the 4th/5th intercostal space just anterior to the mid-axillary line using the approved sterile trauma technique.
    3. If that cannot happen immediately, perform trained needle decompression with a long standard non-valved cannula as a bridge; never use an incompatible closed blood-control cannula.
    4. Insert/secure a definitive chest drain or maintain the thoracostomy according to the resuscitation pathway, then reassess physiology and obtain imaging when stable.
    Stable imaging findingPneumothorax without tension physiology

    Pneumothorax is suspected or imaged but the patient has no severe respiratory compromise or haemodynamic instability.

    1. Obtain appropriate imaging and classify spontaneous, traumatic or iatrogenic cause and high-risk features.

    Key medicines

    Medical oxygenHigh-concentration oxygen via reservoir mask at 15 L/min in severe compromise/peri-arrest; use 100% oxygen during ALS, then titrate after stabilisation to 94–98% or 88–92% if hypercapnia risk.Oxygen does not relieve intrapleural pressure and must never delay decompression. Manage fire risk and titrate down after the emergency.
    Lidocaine 1%If the conscious patient's physiology allows seconds for anaesthesia, infiltrate the lateral thoracostomy/drain tract; total lidocaine without adrenaline should not exceed 3 mg/kg (1% = 10 mg/mL), using less in frailty/liver disease.Do not delay life-saving decompression in peri-arrest. Avoid intravascular injection and record total dose.
    Open full textbook →Answer 2 questions
    Sources and review status5 sources · checked 27 Aug 2026 · clinical review pending+
    Sources

    Sources and review status

    National guidance is shown before implementation-dependent detail. Typical adult dose examples remain subject to patient factors, contraindications and the live BNF or specialist protocol. Source check completed 27 Aug 2026; clinical approval remains outstanding.

    • NICE NG39: Major trauma—recommendationsDecompression before imaging and open-thoracostomy preference.
    • Resuscitation Council UK 2025: Special circumstancesTension pneumothorax as an immediately treatable reversible cause.
    • Resuscitation Council UK 2025: Adult advanced life supportPOCUS limits during arrest and reversible-cause management.
    • NHS England alert: blood-control cannula and needle thoracostomyNational equipment-safety warning.
    • BTS Clinical Statement on Pleural ProceduresDefinitive pleural-drain technique and safety.

    Editorial contact: Doctor’s Passport editorial team. Source-check date is separate from clinical approval. Report a content problem · Content changes

    Authoring stateRapid draftClinical stateAwaiting reviewJurisdictionUnited Kingdom
    Manage through the relevant pneumothorax pathway—conservative, ambulatory, aspiration or drain—rather than labelling every mediastinal shift as tension.
  • Continue close observation; if physiology deteriorates, switch immediately to the unstable decompression pathway.