Pleural disease Flashcards
Causes of pleural effusion
Raised hydrostatic pressure (CCF)
Low oncotic pressure (hypoalbuminaemia)
Low pleural pressure (atelectasis)
Increased endothelial permeability (inflammation -blood and proteins)
Low lymph drainage (malignancy, protein rich)
Cyclothorax (thoracic duct rupture)
Haemothorax (trauma)
Empyema (closed infection in pleural space)
How do you distinguish between empyema and a parapneumonic effusion?
Parapneumonic effusions are pleural effusions that occur secondary to pneumonia
Empyema is pus in the pleural cavity
Give 2 examples of changes which cause transudate formation
Increased hydrostatic pressure
Low oncotic pressure
Give 2 examples of changes which cause exudate formation
Neoplasms
Infection
Inflammation
What is a loculated effusion
A fluid collection with a high protein content that forms fibrous precipitates which walls off the fluid into separate compartments. Pleura normally stuck together in these regions
Pleurisy
Pleural inflammation. Produces a sharp pain on inspiration or movements of the chest wall (coughing, laughing).
Pleural rub heard on auscultation.
What is the function of pleural fluid
serous fluid that lubricates the pleura and prevents friction
Describe the structure of the pleura
The pleura is a serous membrane which folds back onto itself to form a two-layered membrane structure.
The thin space between the two pleural layers is known as the pleural cavity and normally contains a small amount of pleural fluid.
The outer pleura (parietal pleura) is attached to the chest wall. The inner pleura (visceral pleura) covers the lungs and adjoining structures, via blood vessels, bronchi and nerves.
Classification of exudate and transudate
Depends on protein content
For values in between use Light’s critera. Compares protein and LDH in the fluid with serum. Higher levels of protein in fluid =exudate
