Pneumothorax and Respiratory Care

PNEUMOTHORAX

A pneumothorax exists when gas accumulates in the pleural space, which is located between the visceral and parietal pleura.

Tension Pneumothorax:
- Air enters the pleural space, compresses the lung, and shifts the mediastinum.
- Clinical features may include tracheal deviation, increased respiratory rate (RR), hyperresonance on percussion, diminished breath sounds on auscultation, and potential for hypotension due to compromised venous return.
- Treated with needle decompression in the 2nd intercostal space at the midclavicular line, followed by tube thoracostomy.

Lung collapse due to pneumothorax leads to:
- Atelectasis (collapse of lung tissue)
- Asymmetrical chest wall expansion
- Compression of the great veins leading to decreased cardiac venous return

Closed Pneumothorax:
- Gas in pleural space is not in direct contact with the atmosphere.
Open Pneumothorax:
- Pleural space is in direct contact with atmosphere, allowing gas movement in and out.
Tension Pneumothorax:
- Gas enters during inspiration but cannot exit during expiration due to a ruptured parietal pleura, making it the most serious type.

Traumatic Pneumothorax:
- Caused by penetrating wounds from knives, bullets, or other objects.
Spontaneous Pneumothorax:
- Occurs suddenly without an apparent cause; may be secondary to pneumonia, tuberculosis (TB), and chronic obstructive pulmonary disease (COPD) with blebs and bullae on the lung surface that pop. More common in tall, thin persons aged 15-35.
Iatrogenic Pneumothorax:
- Occurs during diagnostic or therapeutic procedures such as:
- Pleural or liver biopsy
- Thoracentesis
- Intercostal nerve block
- Cannulation of a subclavian vein
- Tracheostomy (perforation of the posterior tracheal wall can lead to pneumomediastinum)
- High pressure during mechanical ventilation can cause a pneumothorax.
- Note: Cannot be caused with an endotracheal (ET) tube placement.

Increased respiratory rate (RR) due to stimulation of peripheral chemoreceptors.
Paradoxical movement of the chest wall leading to pendelluft (abnormal air movement between lungs).
Increased heart rate (HR) and blood pressure (BP).
Symptoms include hypoxemia, pain, anxiety, and cyanosis.
Chest assessment findings include:
- Hyperresonance over the pneumothorax
- Diminished breath sounds over the pneumothorax
- Tracheal shift away from the affected side
- Displacement of heart sounds.

Due to pendelluft, lung collapse, and atelectasis:
- The V/Q (ventilation/perfusion) ratio decreases, leading to reduced alveolar ventilation.
- This results in intrapulmonary shunting and venous admixture.
- The partial pressure of oxygen in arterial blood (PaO2) decreases, which may stimulate peripheral chemoreceptors to increase the ventilatory rate.

15% to 20% lung collapse:
- Management includes bed rest or limited physical activity;
- Expect resorption of intrapleural gas within 30 days.
Greater than 20% lung collapse:
- Requires chest tube insertion (thoracostomy) to evacuate air or needle aspiration.
Pleurodesis:
- A chemical is injected into the chest cavity to produce an inflammatory reaction making the lung adhere to the chest wall, preventing recurrence.
Oxygen Therapy and Lung Expansion Therapy may also be employed.
Mechanical Ventilation might be required in severe cases.

Creation of an opening in the chest wall to place a chest tube (thoracic catheter).
Allows drainage of air or fluid from the chest.
The chest tube is attached to an underwater seal to prevent the patient from drawing air back into the pleural space.
Suction may be applied, but negative pressure should not exceed -12 cmH20; -5 cmH2O is typically sufficient.
After lung re-expansion and cessation of bubbling from the tube, it is kept in place for an additional 24 to 48 hours without suction.

Involves the application of talc or other irritants between the pleural linings, promoting adhesions and sealing the pleural space to prevent recurrence of pneumothorax.