Pleural effusion Flashcards
What is pleural effusion?
Fluid collecting between parietal + visceral pleura
What are the 2 types of fluid pleural effusions can be classified upon?
Transudate: <30g/L protein
Exudate: >30g/L protein
What mechanism causes an exudate?
Inflammation causes increased permeability of pleural capillaries- leaking intravascular fluid (cells, their contents + proteins)
What mechanism causes a transudate?
Hydrostatic forces cause extravasation of fluid through a normal membrane
Give 4 causes of transudative pleural effusion
HF (most common)
Hypoalbuminaemia
Hypothyroidism
Meig’s syndrome
Give 3 causes of hypoalbuminaemia
Liver disease
Nephrotic syndrome
Malabsorption
Give 7 causes of exudative pleural effusion
Infection
Malignancy
CTDs: RhA + SLE
PE
Pancreatitis
Dressler’s syndrome
Yellow nail syndrome
Give 3 infectious causes of pleural effusion
Pneumonia (most common exudative cause)
TB
Subphrenic abscess
List 3 types of malignancy that can cause exudative pleural effusion
Lung cancer
Mesothelioma
Mets
What criteria is used to determine if the fluid is an exudate?
Light’s criteria
Ratio of pleural fluid to serum protein >0.5
Ratio of pleural fluid to serum LDH >0.6
Pleural fluid LDH >2/3 the upper limit of normal serum value
What is indicated by frankly purulent fluid?
Empyema
What is indicated by milky fluid? What is this likely caused by?
Chylothorax or pseudochylothorax
Lymphatic obstruction secondary to malignancy, chronic inflammation or thoracic duct injury
What is indicated by bloody fluid?
Trauma
(Less commonly TB, PE, aortic dissection, ruptured aortic aneurysm, malignancy)
What does the presence of food particles indicate?
Oesophageal rupture
What is black pleural fluid indicative of?
Extremely rare!
Aspergillus niger infection
Malignant melanoma
Haemorrhage + haemolytic a/w non-small cell lung cancer
What does pleural fluid LDH level >1000 IU/L indicate?
Empyema
Malignancy
Rheumatoid effusion
Give 3 symptoms of pleural effusion
Dyspnoea
Non-productive cough
Chest pain
Give 3 signs of pleural effusion
Dullness to percussion
Reduced breath sounds
Reduced chest expansion
What investigations should be performed in pleural effusion?
PA CXR
+/- US
+/- Contrast CT
Why is US recommended in pleural effusions?
Increases likelihood of successful pleural aspiration + is sensitive for detecting pleural fluid septations
Why is CT increasingly performed in pleural effusion?
Ix underlying cause, esp if exudative
When should Light’s criteria be used?
Protein level 25-35g/L
How should pleural aspiration be performed?
US guided
21G needle + 50ml syringe
Fluid sent for pH, protein, LDH, cytology + microbiology
What does low glucose in pleural fluid indicate?
Empyema
RhA
TB
What does raised amylase in pleural fluid indicate?
Pancreatitis
Oesophageal perforation
What is first line management for pleural effusion caused by congestive HF?
What should be considered if symptomatic, large effusion?
Furosemide PO/ IV
Consider therapeutic thoracentesis
What is first line management for pleural effusion caused by infection?
IV Abx: Co-amoxiclav + Metronidazole IV
Therapeutic thoracentesis if clinical deterioration/ increasing fluid
What do all patients with a pleural effusion in a/w sepsis or pneumonic illness require?
Diagnostic pleural fluid sampling
Purulent or turbid/ cloudy: insert chest drain
Clear but pH <7.2: insert chest drain
Give 4 options for managing patients with recurrent pleural effusions
Recurrent aspiration
Pleurodesis
Indwelling pleural catheter
Drug Mx to alleviate Sx e.g. opioids to relieve dyspnoea
What is first line management for pleural effusion caused by malignancy in a patient with poor performance status?
Therapeutic thoracentesis
What is first line management for pleural effusion caused by malignancy in a patient with good performance status?
Insertion of temporary chest tube + when drained, talc pleurodesis
What is pleurodesis?
Procedure to obliterate the pleural space
Name a complication of rapid drainage via chest drain insertion in pleural effusion
Re-expansion pulmonary oedema
due to lung interstitial damage plus hydrostatic imbalance that occur following rapid expansion of the underlying collapsed lung
When should re-expansion pulmonary oedema be suspected?
Onset of cough +/- SOB
Describe management of suspected re-expansion pulmonary oedema
Clamp chest drain
Urgent CXR
How can re-expansion pulmonary oedema be avoided?
Drain tubing should be clamped regularly in the event of rapid fluid output
i.e. drain output should not exceed 1L of fluid over a short period of time (<6h).
