Pneumothorax - Collapsed Lung Overview
Definition of Pneumothorax
- Pneumothorax is an abnormal collection of air in the chest, specifically in the pleural space.
- The word breaks down to "pneumo" meaning air and "thorax" meaning chest.
Physiology
- The presence of air disrupts the normal negative interpleural pressure.
- This negative pressure is essential for keeping lung tissue expanded against the chest wall.
- When this pressure is disrupted, it can lead to lung collapse (atelectasis), adversely affecting gas exchange.
Classification of Pneumothorax
- Air can enter the pleural space in two main ways:
- From the outside through trauma to the chest wall.
- From the rupture of lung tissue or visceral pleura.
- Types of Pneumothoraces:
- Traumatic Pneumothorax
- Caused by traumatic injuries, either blunt or penetrating.
- Examples include:
- Penetrating stab wounds.
- Blunt injuries leading to rib fractures.
- Iatrogenic Pneumothorax
- Resulting from invasive medical procedures.
- Common causes:
- Thoracic surgery.
- Lung biopsies.
- Central line insertion.
- Tracheostomy.
- Positive pressure mechanical ventilation.
- Especially relevant in ICU patients with high pressures needing careful monitoring.
- Non-Traumatic Pneumothorax
- Known as spontaneous pneumothorax, further categorized into:
- Primary Spontaneous Pneumothorax (PSP)
- Occurs in normal lung tissue without a known cause.
- Secondary Spontaneous Pneumothorax (SSP)
- Results from underlying lung diseases, e.g.:
- COPD (Chronic Obstructive Pulmonary Disease).
- ARDS (Acute Respiratory Distress Syndrome).
- Asthma.
- Tuberculosis (TB).
- Lung cancer.
- Pneumonia.
- Fibrosis.
- Endometriosis.