Pleural effusion Flashcards
Define pleural effusion
Excess fluid in the pleural space
Explain the difference between a pleural effusion which is an exudate vs transudate
Examples of when one is more likely
- exudate: higher protein content >30g/L (protein driven) | often associate with inflammation + increased permeability to protein
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e.g. parapnuemonic effusion, maligancy, TB, Pulmonary infarction from pulmonary embolism
. - transudate: reduced protein content <30g/L (fluid driven)
- e.g. heart failure, liver failure, kidney failure
What can be used to establish whether a pleural effusion is exudative or transudative?
Light’s criteria
- analysis of pleural effusion fluid
- if protein level between 25-35g/L
Exudative if one or more of following:
- pleural fluid/serum protein >0.5
- pleural fluid/serum LDH >0.5
- pleural fluid LDH >2/3 of upper limit of normal
Examples of causes of exudate pleural effusion
- > 30g/L protein
- due to inflammation > protein leaks out of tissues + into pleural space
- Parapneumonic effusion (pneumonia)
- Malignancy
- TB
- Pulmonary infarction from pulmonary embolism
- RA
- SLE
Examples of causes of transudate pleural effusion
- <30g/L protein
- due to increase pleural capillary hydrostatic pressure - heart failure
- due to decreased capillary oncotic pressure - liver failure + nephrotic syndrome
- Meigs syndrome
- hypoalbuminemia
What is Meigs syndrome?
Triad of:
- benign ovarian tumour
- pleural effusion
- ascites
Is high protein content fluid tranudate or exudate?
Exudate
Investigations of pleural effusion
- CXR
- USS of chest
- ECG
- ECHO (if heart failure suspected)
- staging CT (with contrast) if suspect exudative cause
- FBC, U&E, LFT etc.
- USS guided pleural aspiration > analysis + light’s criteria
Describe the radiological findings of a pleural effusion?
- loss of costo-phrenic angle of affected side
- dense homogenous opacities
- upper border of effusion higher laterally than medially
- meniscus: concave upper border to effusion
- tracheal + mediastinal deviation away from effusion
What are some signs found on examination of pleural effusion
- dullness to percussion
- reduced breath sounds
- tracheal deviation away from effusion
What would you find on percussion of pleural effusion?
Stoney dullness
Treatment of pleural effusions
Remove the fluid:
- chest drain
- needle aspiration
- diuresis
- antibiotics: to remove pathogen causing inflammation
- treat cause
What criteria is used to distinguish between transudate + exudate?
Light’s criteria
Fluid fluid protein level in exudate vs transuadte
Exudate >30g/L
Transudate <30g/L
What should pleural aspiration be sent for?
- pH
- protein
- LDH
- cytology
- microbiology
Only indication for urgent chest drain in new pleural effusion
Underlying empyema
(pH of fluid <7.2 or visible pus on aspirate)
