Pneuomothorax and pleural effusion Flashcards
What is a pneumothorax
The presence of air in the pleural space
What is a primary pneumothorax
Where a pneumothorax has occured spontaneously without evidence of other lung disease
What is a secondary pneumothorax
Where a pneumothorax has occurred secondary to an underlying lung disease such as COPD or CF
Who is likely to present with a spontaneous primary pneumothorax
Healthy young, tall, thin man
Where do most pneumothoraces arise from
The rupture of subpleural blebs or bullae at the apex of an otherwise normal lung
Is smoking a risk factor for a pneumothorax
Yes
What is a tension pneumothorax
Where the lung is pushed down , the mediastinum is shifted to the opposite side and the venous return tot he heart and cardiac output is impaired
What is a key finding on a CXR of a tension pneumothorax
The trachea is deviated to one side
How does a traumatic pneumothorax occur
Puncture of the lung by a fractured rib
How might a Iatrogenic pneumothorax occur
Doctor induced - complication of invasive chest procedures such as the insertion of a catheter into the subclavian vein or during lung aspiration
WHat are the 2 most common clinical features of a pneumothorax
Acute pleuritic pain and breathlessness
What are the clinical signs of a pneumothorax
Reduced breath sounds and hyper-resonance on the side of the pneumothorax
What can be seen on a CXR of a pneumothorax
Black space with no lung markings
What are the limits of a small pneumothorax
Where the rim of air between the margin of the collapsed lung and chest wall is less than 2cm
What defines a large pneumothorax
Where the rim of air between the margin of the collapsed lung and chest wall is more than 2cm
What should be done for a small pneumothorax
Nothing - will resolve spontaneously
When is aspiration appropriate and where is this performed?
In a large pneumothorax
Second intercostal space in the mid-clavicular line
What is indicated if more than 2.5L of air has been aspirated
A persistent air leak from the lung
What does bubbling on respiration or coughing indicate
Continued drainage of air
When is surgical intervention required
For persistent or recurrent peumothoraces
What is involved in a pleurectomy
Removal of the parietal pleura
What is involved in a pleurectomy
Removal of the parietal pleura
What is a pleural effusion
A collection of fluid in the pleural space
What is the parietal pleura perfused by
The systemic circulation
What is the visceral pleura perfused by
The pulmonary circulation
Why does fluid not normally collect in the pleural space
The balance between fluid filtration by the parietal pleura and fluid absorption by the visceral pleura prevents this
What might cause the development of a pleural effusion
Increased capillary pressure
Reduced plasma oncotic pressure
Increased capillary permeability
obstruction of lymphatic drainage
What do patients most commonly present with when they have a pleural effusion
Dyspnoea
Sometimes pleuritic pain
Often features of associated disease (cardiac faulrue or carcinoma)
What are the signs fo pleural effusion
Decreased expansion on the side of the effusion
STONY DULLNESS
diminished breath sounds
reduced tactile vocal fremitus
What are the investgiations involved in diagnosing a pleural effusion
CXR: dense white shadow with a concave upper edge
Ultrasound: helpful in localising loculated eddusions and in positioning chest tubes
CT: helpful in detecting pleural tumours and in assessing the underlying lung and mediastinum
Pleural fluid aspiration: this is the key initial investigation
What indicate that the effision is an exudate
A protein level of more than 30 and a lactate dehydrogenase level of more than 200
What does a blood stained aspirate point towards
Malignancy, pulmonary infarction or severe inflammation
What does pus indicate
Empyema
What does milky white fluid suggest
A chylothorax
What is suggestive of a haemothorax
Frank blood
What are the predominant cells in acute inflammation or infection
Neutrophils
What are the cells found in chronic effusions particularly caused by TB or malignancy
Lymphocytes
What is radiologically guided biopsy is particularly useful in diagnosing?
Malignant disease of the pleura
What are the 4 main causes of transudative pleural effusions
Cardiac failure
renal failure
hepatic cirrhosis
hypoproteinaemia (malnutrition or nephrotic syndrome)
What relieves dyspnoea
Drainage of the fluid by needle aspiration or intercostal chest tube
How is an empyema produced
A secondary infection of an effusion with multiplication of bacteria in the pleural space (pus in the pleural cavity)
What is the initial antibiotic treatment for empyema
Co-amoxiclav with metronidaxole
What is the key treatment for empyema?
Drainage of the pus
What do connextive tissue diseases that are associated with effusions characteristically have
A low glucose content
What is Dressler’s syndrome ?
It consists of inflammatory pericarditis and pleurisy of uncertain aetiology following an MI or cardiac operation (4-6 weeks after)
What is an unusual cause of a pleural effusion but is a medical emergency
Rupture of the oesophagus
