Emergency Central is a collection of disease, drug, and test information including 5-Minute Emergency Medicine Consult, Davis’s Drug, McGraw-Hill Medical’s Diagnosaurus®, Pocket Guide to Diagnostic Tests, and MEDLINE Journals created for emergency medicine professionals. Explore these free sample topics:
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- Presence of free air in the intrapleural space
- Spontaneous pneumothorax is due to atraumatic rupture of alveolus, bronchiole, or bleb.
- Primary spontaneous pneumothorax (2/3 of incidences):
- No underlying pulmonary pathology present
- Rupture of small subpleural cyst or bleb
- Primarily young, healthy patients (20–40 yr old) with tall, thin body habitus
- Risk factors: Smoking, family history, Marfan syndrome, homocystinuria, thoracic endometriosis
- Secondary spontaneous pneumothorax from underlying pulmonary pathology (see Etiology)
- Tension pneumothorax:
- Air continues to enter pleural space through bronchoalveolar disruption and becomes trapped via “ball-valve” mechanism.
- Intrapleural pressure increases.
- Venous return to right heart decreases, resulting in decrease in cardiac output.
- Mediastinum shifts toward uninvolved side, mechanically interfering with right atrial filling.
- Ventilation compromise and ventilation/perfusion mismatch result in hypoxemia
- Airway disease:
- Chronic obstructive pulmonary disease (COPD)
- Cystic fibrosis
- Necrotizing bacterial pneumonia
- Fungal pneumonia
- Pneumocystis carinii
- Interstitial lung disease:
- Idiopathic pulmonary fibrosis
- Tuberous sclerosis
- Connective tissue diseases
- Pulmonary infarction
- Blunt chest trauma
- Penetrating trauma to neck or trunk
- Central line placement
- Other vascular access procedures