Pleural Effusion Flashcards
What is a pleural effusion
A collection of fluid in the pleural space
What causes a pleural effusion
When the balance between fluid filtration by the parietal pleura and fluid absorption by the visceral pleura is no longer balanced, leading to a build up of fluid in the pleural space
What might a patient with pleural effusion complain of
Breathlessness - sometimes with pleuritic pain
Does pleural effusion cause clubbing
No
What would you expect to find on examination of a patient with a pleural effusion
Tachypnoea Deviated trachea - away from effusion Asymmetrical decreased chest expansion Reduced tactile vocal fremitus Stony dull to percussion Reduced breath sounds
- Bronchial breath sounds may be heard at the top of the effusion
- Any signs of failure/malignancy that may indicate a cause
What is aegophony
Bronchial breathing at the top of an effusion
What diagnostic investigations would be done for a patient with a suspected pleural effusion
CXR
Pleural tap
What would you test the pleural tap for in a pleural effusion
Protein Glucose LDH Cell count Culture and microscopy Cytology pH
What information does the protein level in a pleural tap give you
Whether the effusion is a transudate or an exudate
What is a transudate
An effusion with a protein content less than 30
What is an exudate
An effusion with a protein content >30
How would transudates and exudates appear on a pleural tap
Yellow, straw colour
What information does the glucose in a pleural tap give you
Low glucose points towards infection or connective tissue disease as the cause of the effusion
What information would you get from the cell count in a pleural tap
Neutrophils - predominant cells in acute inflammation or infection
Lymphocytes - predominant cells in chronic effusions, particularly caused by TB or malignancy
What might cytology show on a pleural tap
Malignant cells
What might microbiology examination of pleural fluid show
May identify TB or bacterial infection
What would bloodstained pleural fluid indicate
Malignancy
Pulmonary infarction
Severe inflammation
What would pus in pleural fluid indicate
Empyema
What would frank blood in pleural fluid indicate
Haemothorax
How do you determine if the pleural fluid is a transudate or an exudate in cases where the protein level is borderline ie. 25-35
Lights Criteria
What is Lights Criteria
Pleural fluid protein/Serum protein >0.5
Pleural fluid LDH/Serum LDH >0.6
Pleural fluid LDH > 2/3 upper limit of normal
If any one of these criteria is met, effusion is considered an exudate
What are some causes of a transudate
3 Failures
- Cardiac failure
- Renal failure
- Liver failure
Hypoalbuminaemia
Hypothyroidism
*Transudative effusions are commonly bilateral
What are some causes of an exudate
MIII
Malignancy - metastatic carcinoma, mesothelioma
Infection - TB, empyema
Infarction - pulmonary infarction
Inflammation - SLE, RA, benign asbestos effusion
- Exudates results from increased permeability of the pleura associated with pleural disease
- Exudates are usually unilateral
What is Meig’s syndrome
A rare cause of transudative pleural effusion
Benign ovarian pathology
Ascites
Right sided pleural effusion
