Pleural Disease - Pleural Effusion Flashcards
What is a mesothelial layer?
Membranes formed by simple squamous epithelium
What is the pleura made of?
Single layer of mesothelial cells
What is the pressure in the pleural cavity?
-0.66kPa
What is the pleural cavity lubricated by?
2-3ml of pleural fluid
Fluid has high turnover
How does pleural fluid absorb into blood?
Due to plasma osmotic pressure
How does fluid move into the pleural cavity?
Via positive systemic and pulmonary arterial pressures pushing it into the negative pressure cavity
What are structures that can be damaged in a pleural procedure?
Subclavian vein/arteries
Liver
Kidney’s
Spleen
What is pleural effusion?
Abnormal collection of fluid in the pleural cavity
What are the two types of pleural effusion?
Transudates - fluid protein <30g/l
Exudates - fluid protein >30g/l
What causes transudates?
Imbalance of hydrostatic forces causes overproduction of fluid and over absorption normally due to altered capillary permeability
Are transudates bilateral or unilateral?
Usually bilateral
Name a cause of transudate pleural effusion?
LV failure
How do exudates make it into the pleural cavity?
Increased permeability of the pleural surface and/or local capillaries, often due to inflammation
Are exudates bilateral or unilateral?
Often unilateral
Causes of exudates?
Malignancy
Pneumonia or Lung Abscess
Pulmonary embolism
Symptoms of a pleural effusion?
Can be asymptomatic
Increasing dyspnoea
Pleuritic chest pain
Dry cough
What are the patterns of the pleuritic chest pain for inflammatory causes vs malignancy?
Inflammatory - early pain that may improve as fluid accumulates
Malignancy - pain the gradually keeps getting worse
What signs are seen on the affected side of chest during examination?
Reduced chest expansion, breath sounds and vocal resonance
Stony dullness to percussion
What other signs are there?
Signs of underlying disease - clubbing, lymphadenopathy, increased JVP
Trachea deviated away from a large effusion - if unchanged may indicate a collapse
What investigations can be done?
CxR
CT thorax
Pleural aspiration and biopsy
What can a CxR see?
Fluid build up - needs to be over 200ml before it shows
What can a CT thorax see?
Can differentiate between malignant and benign diseases
What can be noted of the liquid sample taken via aspiration before sending off to lab?
Foul smell - anaerobic empyema
Pus - empyema
Food particles - oesophageal rupture
Blood - malignancy, haemothorax, trauma
Treatment for a pleural effusion?
Pleurodhesis
- Fluid must be drained
- Patient at 45 degreed with arm above head
- Drain in 4th intercostal space in mid-axilliary line
Drain no faster than 500ml/hr and drain til dry - check with a CxR
Talc is inserted through a chest tube to cause inflammation then removed after a few hours.
This seals pleural space with scar tissue stopping fluid build up again
