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EM TopicsPneumothorax

EM · Pneumothorax

Pneumothorax (including tension pneumothorax)

Also known as Spontaneous pneumothorax · Primary pneumothorax · Tension pneumothorax

Pneumothorax — primary and secondary spontaneous, traumatic, iatrogenic, and tension. The one-way-valve pathophysiology of tension and why it kills, the clinical (not radiological) diagnosis of tension, the 5th-intercostal-space decompression site, the size-based management of a spontaneous pneumothorax (observe, aspirate, drain), the chest-drain landmarks and the underwater seal, the re-expansion-oedema pitfall, and the bulla-mimic trap. ACEM-primary, globally tagged.

high6 referencesUpdated 26 July 202616 min readVerification in progress

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Target exams

ACEMFRCEMABEMFRCPCCCFPEMEBEEM

Red flags

  • Tension pneumothorax is a CLINICAL diagnosis — hypotension, hypoxia, distended neck veins and absent breath sounds on one side — decompress immediately, do NOT wait for a chest radiograph
  • Decompress at the 5th intercostal space, anterior to mid-axillary line, with a device long enough to reach the pleura — the chest wall is often thicker than a standard intravenous cannula
  • A sudden deterioration with rising airway pressure and hypotension in a ventilated patient is a tension pneumothorax until proven otherwise
  • A giant bulla can mimic a pneumothorax on a chest radiograph — confirm with CT before draining, or you create a bronchopleural fistula
  • Rapid re-expansion of a large, long-standing pneumothorax causes re-expansion pulmonary oedema — drain incrementally
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Related topics

  • Pulmonary embolism (acute, in the emergency department)
  • Respiratory failure (type 1 and type 2)
  • Acute severe asthma
Study tools

Your progress

Saved on this device.

Target exams

ACEMFRCEMABEMFRCPCCCFPEMEBEEM

Red flags

  • Tension pneumothorax is a CLINICAL diagnosis — hypotension, hypoxia, distended neck veins and absent breath sounds on one side — decompress immediately, do NOT wait for a chest radiograph
  • Decompress at the 5th intercostal space, anterior to mid-axillary line, with a device long enough to reach the pleura — the chest wall is often thicker than a standard intravenous cannula
  • A sudden deterioration with rising airway pressure and hypotension in a ventilated patient is a tension pneumothorax until proven otherwise
  • A giant bulla can mimic a pneumothorax on a chest radiograph — confirm with CT before draining, or you create a bronchopleural fistula
  • Rapid re-expansion of a large, long-standing pneumothorax causes re-expansion pulmonary oedema — drain incrementally
The one-line answer

A pneumothorax is air in the pleural space — usually a size-managed problem (observe, aspirate, or drain), except for tension pneumothorax, which is a clinical diagnosis you decompress before any imaging at the fifth intercostal space, anterior to the mid-axillary line, with a device long enough to reach the pleura. The Fellowship hinge is the same every time: recognise tension by the bedside, do not wait for a film, and never confuse a giant bulla for a pneumothorax.[1][2][3]

Meet the patient

A 24-year-old tall, thin man walks into your resus bay at 3am, sweating and gasping, with sudden right-sided pleuritic chest pain that woke him an hour ago. He looks unwell: respiratory rate 32, SpO₂ 90 per cent on room air, and he cannot finish a sentence.[1]

Now imagine the same man five minutes later, but intubated for trauma: the ventilator alarms, peak airway pressure climbs, BP falls to 70 systolic, and the right side of his chest is silent and hyperresonant. That is the picture every ACEM candidate must convert to a reflex — tension, decompress now. Hold both patients in mind; this topic is the story of why one of them is an emergency and the other is a procedure.[1][2]

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References6ShowHide
  1. [1]MacDuff A, Arnold A, Harvey J, et al. Management of spontaneous pneumothorax: British Thoracic Society Pleural Disease Guideline 2010 Thorax, 2010.PMID 20696690
  2. [2]Ahmad SJS, Degiannis JR, Head M, et al. Meta-analysis of the optimal needle length and decompression site for tension pneumothorax and consensus recommendations on current ATLS and ETC guidelines World J Emerg Surg, 2025.PMID 40383767
  3. [3]Roberts ME, Rahman NM, Maskell NA, et al. British Thoracic Society Guideline for pleural disease Thorax, 2023.PMID 37553157
  4. [4]Laan DV, Vu TD, Thiels CA, et al. Chest wall thickness and decompression failure: A systematic review and meta-analysis comparing anatomic locations in needle thoracostomy Injury, 2016.PMID 26724173
  5. [5]Tschopp JM, Bintcliffe O, Astoul P, et al. ERS task force statement: diagnosis and treatment of primary spontaneous pneumothorax Eur Respir J, 2015.PMID 26113675
  6. [6]Uttamani RR, Venkataram A, Venkataram J, et al. Tumescent Anesthesia for Dermatosurgical Procedures Other Than Liposuction J Cutan Aesthet Surg, 2020.PMID 33911407
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Related topics

  • Pulmonary embolism (acute, in the emergency department)
  • Respiratory failure (type 1 and type 2)
  • Acute severe asthma