[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
What does pulsus paridoxicus suggest in pneumothorax?
A severe pneumothorax
In what situation in particular might hypotension and raised JVP be present in pneumothorax?
Tension pneumothorax
What are the differential diagnoses of pneumothorax?
- Pleural effusion
- Chest pain
- Pulmonary embolism
What does a tension pneumothorax require?
Urgent decompression
How should a tenson pneumothorax be managed?
The patient should be given oxygen, and then a large-bore needle should be inserted into the pleural space through the second or third anterior intercostal space. Following this, a chest drain can be inserted
What confirms the diagnosis of tension pneumothorax?
A gush of air on decompression
Should a tension pneumothorax be decompressed before or after CXR conformation?
Before
What does the management of a primary pneumothorax depend on?
If there is SOB and/or a rim of air of 2cm on CXR
How should a primary pneumothorax be managed if there is SOB and/or a rim of air >2cm on CXR?
Aspiration should be attempted. If this is not successful, then a chest drain should be inserted
How should a primary pneumothorax be managed if there is no SOB, or a rim of air <2cm on CXR?
Consider discharge and outpatient review in 2-4 weeks
Where is the puncture site in needle aspiration of a pneumothorax?
Commonly in 2nd or 3rd intercostal space in the midclavicular line, or in the 4th or 5th intercostal space over the superior rib margin in the anterior axillary line
In what respects are needle aspiration and chest-drains the same in management of pneumothorax?
There is no significant difference between aspiration and chest drain with regard to immediate success rate, early failure rate, duration of hospitalisation, and one-year success rate
What is the advantage of needle aspiration over chest drain in the management of pneumothorax?
Needle aspiration is associated with reduction in the proportion of patients hospitalised in comparison with chest drain
What are the indications for a chest drain in pneumothorax?
- Any ventilated patient
- Tension pneumothorax after initial needle relief
- Persistent or recurrent pneumothorax after simple aspiration
- Large secondary spontaneous pneumothorax in patients over 50 years
What are the most frequent complications of intercostal drainage (chest drain)?
- Pain
- Intrapleural infection
- Wound infection
- Drain dislodgement
- Drain blockage
How should a secondary pneumothorax be managed when there is SOB or a rim of air >2cm on CXR?
Chest drain
How should a secondary pneumothorax be managed if there is a rim of air 1-2cm on CXR?
Attempt aspiration. If unsuccessful, chest drain
How should a secondary pneumothorax be managed if the rim of air is under 1cm?
Admit for 24 hours for observation and oxygen
What is pleurodesis?
Obliteration of the pleural space
When should pleurodesis be considered in pneumothorax?
If there has been a recurrence, or if risk is considered high
What is the advantage of surgical pleurodesis?
It is more effective
What is the disadvantage of medical pleurodesis?
It may be more appropriate for patients who are unwilling or unable to undergo surgery
How can surgical pleurodesis be performed?
Via thoracotomy or thoracoscopy
What does surgical pleurodesis involve?
Mechanically irritating the parietal pleura, often with a rough pad
Surgical removal of the parietal pleura is also an effective way of achieving stable pleurodesis
What does medical pleurodesis involve?
The administration of chemicals such as bleomycin, tetracycline, or a slurry of talc into the pleural space through a chest drain. The chemicals cause irritation, and prevents further fluid from accumulating
What is required due to the fact that medical pleurodesis is painful?
Patients should be premediated with a sedative and analgesics. A local anesthetic can be instilled into the pleural space
What are the potential complications of pleurodesis?
- Failure to prevent recurrence
- Acute respiratory distress
- Infection of the pleural space
- Persistent air leak
Re-expansion of pulmonary oedema
