[3] Pneumothorax Flashcards
What is a pneumothorax?
A collection of air in the pleural cavity (between the lung and the chest wall) resulting in collapse of the lung on the affected side
What is the extent of the collapse in pneumothorax depenent on?
The amount of air that is present
What is the thoracic cavity?
The space inside the chest that contains the lungs, heart, and numerous major blood vessels.
Describe the pleura in the thoracic cavity
The visceral pleura covers the surface of hte lung, and the parietal pleura lines the inside of the chest wall. Normally, the two layers are separated by a small amount of lubricating serious fluid.
Why are the lungs fully inflated in the thoracic cavity?
Because the pressure in inside the airways is higher than the pressure inside the pleural space
When can a pneumothorax form?
When air is allowed to enter into the pleural space, thus increasing the pressure
What might allow air into the pleural space?
- Damage to the chest wall
- Damage to the lungs themselves
When does a tension pneumothorax form?
When the opening that allows air to enter the pleural space functions as a one-way valve, allowing more air to enter with every breath, but none to escape
What worsens the problem in a tension pneumothorax?
The body tries to compensate by increasing the respiratory rate and tidal volume
What is a primary spontaneous pneumothorax?
A pneumothorax occuring in healthy people
What is a secondary pneumothorax?
A pneumothorax associated with an underlying lung disease, e.g. rupture of congential bulla or cyst in COPD
How does a secondary pneumothorax compare to a primary pneumothorax clinically?
The management is potentially more difficult, and the consequences are significantly greater
What is a traumatic pneumothorax?
One that occurs after a penetrating chest trauma, such as a stab wound, gunshot injury, or fractured rib
What is an iatrogenic pneumothorax?
One following a medical procedure
What medical procedures might cause an iatrogenic pneumothorax?
- Mechnical ventilation
- Interventional procedures such as central line placement, lung biopsy, or percutaneous liver biopsy
What is a tension pneumothorax?
A life-threatening emergency that requires instant action for the severe symptoms and signs of respiratory distres
What are the typical clinical situations where a tension pneumothorax arise?
- Ventilated patients
- Trauma patients
- Resuscitation patients
- Lung disease, especially in acute presentations of asthma and COPD
- Blocked, clamped, or displaced chest drains
- Patients receiving non-invasive ventilation
- Patients undergoing hyperbaric oxygen treatment
What is the risk factors for pneumothorax?
- Smoking
- Tall stature
- Endometriosis
- Underlying lung conditions
- Family history
Give 6 examples of lung conditions that increase the risk of a pneumothorax
- COPD
- Tuberculosis
- Sarcoidosis
- Cystic fibrosis
- Malignancy
- Idiopathic pulmonary fibrosis
How do the symptoms of a primary and secondary pneumothorax compare?
Symptoms of a primary pneumothorax may be minimal or absent. In contrast, symptoms are greater in secondary pneumothorax, even if it is relatively smaller in size.
What investigations are performed in pneumothorax?
- Examination
- Standard erect CXR
- Ultrasound
- CT scanning in uncertain or complex cases
- ABG
What examination findings may be seen in pneumothorax?
- Dyspnoea and potentially cyanosis depending on the degree of respiratory inadequacy
- Tachycardia
- Hypotension and raised JVP, especially in tension pneumothorax
- Reduced chest expansion on affected side
- Trachea devation in tension pneymothorax
- Hyper-resonance on percussion over the collapse
- Breath sounds reduced or absent over affected area
What does a pulse rate over 135 suggest in pneumothorax?
Tension pneumothorax
What is pulsus paridoxicus?
Abnormally large drop in pulse rate on inspiration
