Pneumothorax Flashcards
What is a pneumothorax?
Where air gets into the pleural space, separating the lung from the chest wall
What are ways a pneumothorax can occur?
Spontaneously, secondary to trauma, by medical interventions or by lung pathology.
What is a primary pneumothorax?
Occurs in a patient without a known respiratory disease
What is a secondary pneumothorax?
Occurs in a patient with a pre-existing respiratory disease?
What is a tension pneumothorax?
Caused by trauma to the chest wall that creates a one-way valve that lets air in but not out of the pleural space.
What is the cause of primary pneumothorax?
Often unknown but may be due to rupture of subpleural air bleb, the bleb is caused by alveolar rupture, which lets air travel through the interlobular septum into the subpleural space.
What conditions can cause secondary pneumothorax?
COPD, Asthma, Cystic fibrosis, Marfan syndrome
What is the cause of secondary pneumothorax with COPD and asthma?
rupture of the air bulla
What is the cause of secondary pneumothorax with Cystic fibrosis?
endobronchial obstruction causing increased pressure in the alveoli, leading to alveolar rupture.
What is the cause of secondary pneumothorax with marfan syndrome?
increased formation of air bulla rupture
tall body habitus increased mechanical stress on lung apices (exacerbating the bulla rupture)
What are the main causes of a tension pneumothorax?
Penetrating/blunt trauma, mechanical ventilation or non-invasive ventilation, conversion of a tension pneumothorax
How is the physiological function affected by a pneumothroax?
A one-way valve means air is trapped in the pleural space, intrapleural pressure exceeds atmospheric pressure, leading to the collapse of the ipsilateral lung.
What has pushed away from the pneumothorax in a tension pneumothorax?
The mediastinum and kink are the big vessels
What effect does a shift in the mediastinum have on the heart?
It can compress the heart and surrounding vasculature, reducing the cardiac output and venous return. If untreated it can lead to cardiac arrest.
What are the signs of a tension pneumothorax?
Tracheal deviation, reduced air entry to the affected side, increased resonance to percussion on the affected side, tachycardia, hypotension
What are the clinical findings of a tension pneumothorax?
Hyper-resonant lung percussion, reduced breath sounds, reduced lung expansion
What are the bedside investigations performed in a pneumothorax?
Pulse oximetry and lung ultrasound (absenece of lung sliding) in supine trauma patients.
What are the laboratory investigations performed?
FBC (blood transfusion), clotting screen (correct coagulopathy) and ABG (respiratory alkalosis)
What imaging would be connducted?
Chest x ray and CT
What would you be looking for on a chest x-ray of a patient with a pneumothorax?
Visible rim between the lung margin and chest wall, with an absence of lung markings
What measurement does a pneumothorax get classified as a “large” pneumothorax?
> 2cm
Where is the size of a pneumothorax measured?
Hilum
Why would a CT be used?
To identify small pneumothoraces or the cause (can show air bulla or emphysematous changes)
Where should you insert an aspiration cannula?
‘Insert a large bore cannula into the second intercostal space in the midclavicular line’.
Where should you insert a chest drain?
In the triangle of safety, the 5th intercostal space, the mid axillary line and the anterior axillary line
What should you look out for once the chest drain is inserted?
Swinging and bubbling.
What should the persistence of bubbling for >48 hours indicate?
An air leak, which is the connection between the bronchial tree and pleural space.
When should you aspirate?
If there is greater than >2cm rim of air on the CXR
What should you do to prevent the lung from collapsing?
chemical pluerodesis or surgery
What is chemical pleurodesis?
Make insertion and inserts a tube, then use chemicals to attach the lung to the chest cavity, eliminating extra space in the chest cavity
What is VATS?
A minimally invasive procedure than uses a small camera to help the surgeon remove lung tissue
