Pneumothorax – Quick Consult
Last Updated / Reviewed: October 2024

Definition
Key History
Key Physical Exam
Risk Factors for Pneumothorax
Differential Diagnosis
Diagnostic Testing
Clinical Risk and Safety Pearls
Treatment
Complications

Definition

Pneumothorax Collection of gas in the pleural space resulting in collapse of lung on the affected side.
Primary Spontaneous Pneumothorax (PSP) Pneumothorax that occurs without a precipitating event in a person who has no known underlying lung disease. (Most will end up having unrecognized lung disease.)
Secondary or Complicated Spontaneous Pneumothorax Occurs as a complication of underlying lung disease.
Tension Pneumothorax A life-threatening condition compromising cardiopulmonary function that requires immediate treatment, characterized by tachycardia, hypotension, and cyanosis. See separate topic: Tension Pneumothorax.

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Key History

  • Sudden onset dyspnea
  • Sudden onset pleuritic chest pain
  • May occur at rest or with exertion (primary and secondary respectively)
  • May be asymptomatic
  • Referred pain to shoulder
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Key Physical Exam

  • Findings on the affected side:
    • Diminished breath sounds
    • Hyperresonant percussion
    • Decreased excursion
  • Subcutaneous emphysema
  • Hypoxemia
  • Tachypnea
  • Tachycardia
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Risk Factors for Pneumothorax

  • Acute endometriosis
  • Central line placement
  • Ehlers-Danlos
  • Family history
  • Homocystinuria
  • Liver biopsy
  • Male to female ratio – 6:1
  • Marfan’s syndrome
  • Rapid altitude changes – diving, flying without pressurization
  • Smoker to non-smoker ratio – 20:1
  • Thoracentesis
  • Trauma
  • Pulmonary disease:
    • Adult respiratory distress syndrome
    • Asthma
    • COPD
    • Cystic fibrosis
    • Lung abscess
    • PCP
    • Pulmonary fibrosis
    • Sarcoidosis
    • TB
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Differential Diagnosis

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Diagnostic Testing

Text / literature information and recommendations include:
  • Chest X-ray:
    • Radiographic features - The main radiologic feature of a pneumothorax is a white visceral pleural line, which is either straight or convex towards the chest wall, separated from the parietal pleura by an avascular collection of gas. No pulmonary vessels are visible beyond the visceral pleural edge.
    • Upright chest radiographs - In upright patients, the accumulation of gas occurs primarily in an apicolateral location. As little as 50 mL of pleural gas can be visible. A lateral width of 1 cm corresponds to about a 10% pneumothorax. The size of a pneumothorax is accounted for by the collapsed lung, andto a greater degree, by the expanding chest cage. Despite a considerable loss of volume, the collapsed lung preserves its transradiancy because of hypoxic vasoconstriction that diminishes its blood flow.
    • Inspiratory films are recommended as the initial examination of choice for pneumothorax detection.
    • Lateral decubitus view – A small pneumothorax can be more easily detected in the lateral decubitus view. In this position, as little as 5 mL of pleural gas is visible on the non-dependent side.
    • Tension pneumothorax - Tension pneumothorax shows a distinct shift of the mediastinum to the contralateral side and flattening or inversion of the ipsilateral hemidiaphragm. Should be treated immediately. Take care to differentiate the pleural line from artifact.
  • CT is useful in difficult cases—for example, patients with emphysema as well as critically ill patients who cannot tolerate upright or decubitus films. CT is more sensitive than CXR.

Thoracic ultrasound is emerging as a highly sensitive and specific diagnostic tool for pneumothorax. It is particularly useful in critically ill patients and trauma settings where rapid bedside diagnosis is needed. Ultrasonography has been shown to be superior to supine chest radiography, with a sensitivity of 90.9% and specificity of 98.2%.

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Clinical Risk and Safety Pearls

  • 5 mL of air can be seen on a lateral decubitus view.
  • 50 mL of air can be seen on an upright CXR.
  • 500 mL of air must be present to be seen on a supine CXR.
  • Tension pneumothorax shifts the mediastinum to the opposite side.
  • Catamenial pneumothorax is a pneumothorax associated with menstruation. Seen in women with pelvic endometriosis; rarely seen in women ages 30-50 years. Typically affects the right lung within 72 hours of the onset of menses. Thought to be related to endometriosis involving the pleura.
  • Pregnancy: Pneumothorax is a rare complication of labor and delivery and should be suspected in the pregnant or postpartum patient with dyspnea and chest pain (also consider PE).
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Treatment

The emergency department management of pneumothorax involves several key strategies, tailored to the type, size and clinical presentation of the pneumothorax:

  • Observation: For clinically stable patients with small pneumothoraces, observation for 3 to 6 hours is recommended. If a repeat chest radiograph shows no progression, the patient can be discharged with follow-up instructions.
  • Simple Aspiration: Clinically stable patients with larger pneumothoraces should undergo simple aspiration using a small-bore catheter (≤ 14F). This method is less invasive and can be effective in re-expanding the lung.
  • Chest Tube Drainage: For larger or symptomatic pneumothoraces or if simple aspiration fails, insertion of a chest tube (16F to 22F) is indicated. The tube can be connected to a Heimlich valve or a water-seal device. Suction may be applied if the lung does not re-expand quickly.
  • Minimally Invasive Techniques: Small-bore catheters with Heimlich valves can be used for ambulatory management, reducing the need for hospitalization.
  • Emergent Needle Decompression: In cases of tension pneumothorax, immediate needle decompression followed by chest tube insertion is critical to relieve life-threatening pressure.
  • Surgical Intervention: For recurrent or persistent pneumothorax, video-assisted thoracoscopic surgery (VATS) or thoracotomy with pleurodesis or bullectomy may be necessary.
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Complications

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Alrajhi K, Woo MY, Vaillancourt C. Test characteristics of ultrasonography for the detection of pneumothorax: a systematic review and meta-analysis. Chest. 2012 Mar;141(3):703-708. doi: 10.1378/chest.11-0131. Epub 2011 Aug 25. PMID: 21868468.

Bintcliffe OJ, Hallifax RJ, Edey A, et al. Spontaneous pneumothorax: Time to rethink management? Lancet Respir Med. 2015;3(7):578-588.

Carson-Chahhoud KV, Wakai A, van Agteren JE, et al. Simple aspiration versus intercostal tube drainage for primary spontaneous pneumothorax in adults. Cochrane Database Syst Rev. 2017;9:CD004479.

Hedevang OW, Katballe N, Sindby JE, et al. Cannabis increased the risk of primary spontaneous pneumothorax in tobacco smokers: A case-control study. Eur J Cardiothorac Surg. 2017;52(4):679-685.

Ho KK, Ong ME, Koh MS, et al. A randomized controlled trial comparing minichest tube and needle aspiration in outpatient management of primary spontaneous pneumothorax. Am J Emerg Med. 2011;29(9):1152-1157.

Roberts DJ, Leigh-Smith S, Faris PD, et al. Clinical presentation of patients with tension pneumothorax: A systematic review. Ann Surg. 2015;261(6):1068-1078.

Shah K, Tran J, Schmidt L. Traumatic pneumothorax: updates in diagnosis and management in the emergency department. Emerg Med Pract. 2022 Apr 15;25(5, Suppl 1):1-28. PMID: 35467819

Staub LJ, Biscaro RRM, Kaszubowski E, Maurici R. Chest ultrasonography for the emergency diagnosis of traumatic pneumothorax and haemothorax: A systematic review and meta-analysis. Injury. 2018;49(3):457-466.

Thelle A, Gjerdevik M, SueChu M, et al. Randomized comparison of needle aspiration and chest tube drainage in spontaneous pneumothorax. Eur Respir J. 2017;49(4).

Tschopp JM, Bintcliffe O, Astoul P, et al. ERS task force statement: Diagnosis and treatment of primary spontaneous pneumothorax. Eur Respir J. 2015;46(2):321-335.

This is intended solely as reference material and is not a recommendation for any specific patient. The practitioner must rely upon his or her own professional judgment and medical decision-making to determine whether it is relevant in a particular case. Materials are derived from medical and nursing texts, medical literature and national guidelines and should not be considered complete or authoritative. Users must rely on specific patient presentation, experience and judgment when utilizing any of the information contained herein relative to an actual patient.
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