October 25, 2002

Adult male with severe respiratory distress. 
Blood pressure 60 mmHg over palpable.

Bilateral Tension Pneumothoraces

Tension Pneumothorax

  • Intrapleural pressure > atmospheric pressure

  • One-way valve mechanism

  • Allows air to enter but not exit pleural space

  • Decreased cardiac output

  • Impaired venous return

  • Profound hypoxia due to ventilation-perfusion mismatches

Clinical diagnosis

  • Tachypnea

  • Tachycardia

  • Cyanosis

  • Hypotension


  • Involved hemithorax hyperlucent

  • Depression or inversion of ipsilateral hemidiaphragm

  • Medially retracted lung 

  • Contralateral mediastinal shift

    • does not necessarily indicate a tension pneumothorax 

Chest Radiography: 

  • Requires identification of a radiolucent air space 

  • Separates the visceral pleural line-white line-from the parietal pleura

  • Pulmonary vessels extend to the edge of the visceral pleural line but not 

  • Convexly toward the lateral chest wall

Imaging Studies: 

  • Upright expiration

  • Lateral decubitus ( 5 ml)

  • CT  


  • Recurrence of spontaneous pneumothorax

  • Ipsilateral side < 30%

  • Contralateral side 10%

  • Bronchopleural fistula 3-5% of patients 

  • Pneumomediastinum / pneumopericardium 

  • Reexpansion pulmonary edema

    • Lung is rapidly reinflated after a prolonged period of collapse (e.g., pneumothorax pleural effusion)

    • Mechanical stresses applied to the lung during re-expansion damage the capillaries 

Other Pneumothoraces

Traumatic Pneumothorax: 

  • Penetrating injuries

  • Blunt injuries

    • Acute increase in intrathoracic pressure --> alveolar rupture into pleural space

    • Laceration of tracheobronchial tree

Iatrogenic Pneumothorax: 

  • Interventional procedures

  • Mechanical ventilation

  • Hyperbaric oxygen therapy

Subpulmonic Pneumothorax: 

Primary Spontaneous Pneumothorax: 

  • Age-adjusted incidence

    • 7.4/100,000/year (men)

    • 1.2/100,000/year (women)

    • (Minnesota study)

  • Strong association with smoking

  • Taller / thinner 

  • Inheritable 

  • Rupture of an apical subpleural bleb

Secondary Spontaneous Pneumothorax: 

  • Most have associated

    • Blebs

    • Cysts

    • Cavities

  • Airways disease

    • COPD

    • Status asthmaticus

    • Cystic fibrosis

  • Interstitial lung diseases 

    • Langerhans cell histiocytosis 

    • Lymphangioleiomyomatosis 

    • Rheumatoid disease

    • Idiopathic pulmonary fibrosis 

    • Radiation fibrosis

  • Connective tissue diseases 

    • Marfan's syndrome

    • Ehlers-Danlos

    • Cutix laxa

  • Infectious diseases

    • AIDS with P carinii pneumonia 

    • Mycobacterium tuberculosis 

    • Necrotizing Gram (-) pneumonia 

    • Anaerobic pneumonia 

    • Staphylococcal sp pneumonia 

  • Malignancies

    • Osteogenic sarcoma

    • Lymphoma

    • Germ cell tumors

Catamenial Pneumothorax: 

  • Occurs in conjunctionwith menstruation 

  • Respiratory symptoms develop within 24-48 hrs of onset of menses

  • Subpleural endometrial implants

  • Air gains access to peritoneal cavity and enters the pleural cavity through diaphragmatic defects

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Disclaimer:  This information is intended solely for resident review of presented cases which may or may not be pathologically proven. Information is derived from a number of published sources of varying reliability and does not represent original research from the institution. It is not intended to be comprehensive and should therefore not substitute for careful review of the literature. 

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For medical and imaging questions contact:

Dhenry.jpg (20362 bytes) Daniel A. Henry, MD

Assoc. Professor, Director
Thoracic/Chest Radiology

Main Hospital, rm 3-404

brath.jpg (11480 bytes) Lisa K. Brath, MD

Assist. Professor Pulmonary
& Critical Care Medicine

West Hospital, 16th floor



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