Pleural Disease Flashcards
What is the normal volume of fluid in the pleura?
10-20ml
What is pleural effusion?
When the pleural fluid increases
Does fluid always sink to the bottom in the pleura?
Mostly, but not always
What does TVF stand for?
Vocal fremitus
What does VR stand for?
Vocal resonance
What does TVF and VR show?
Presence of fluid → sound waves are poorly conducted through fluid
What are symptoms of pleural effusion?
- Productive cough
- Fever
- Crackles
- Percussion is stony (bc fluid) and dull
- Tracheal deviation (if large)
- Reduced breath sounds (can get bronchial breath sounds at level of effusion)
What are signs on a CXR of pleural effusion?
1) Can’t see hemidiaphragm
2) Dense white shadowing
3) Shadowing creeps up side of chest wall
What scan would you do after a CXR?
Ultrasound (black = fluid)
What is a thoracocentesis?
A pleural tap to get a sample of the fluid in the effusion
Where do you do the thoracocentesis and why?
Above the rib to avoid the neuromuscular bundle below the rib
What are the different types of samples from a thoracocentesis sent off?
- AFB (TB cultures), MCS (normal cultures, microscopy culture sensitivity)
- Protein, LDH
- Cytology
- Glucose
What are the two types of effusion fluid?
Transudate and exudate
How do you define a transudate?
< 25 g/L of protein
How do you define an exudate?
> 35 g/L (thick fluid with lots of protein and LDH)
What do you do if the pleural fluid has between 25-35 g/L of protein?
You use Light’s criteria
What is Light’s criteria?
Exudate if one or more is true:
1) Pleural protein divided by serum protein is >0.5
2) Pleural LDH divided by serum LDH is <0.6
3) Pleural LDH > ⅔ upper limit of lab normal LDH
What are transudates generally caused by?
Systemic problems i.e. failures - heart, liver, renal
What are v common causes of transudates?
- LV failure (most common)
- Liver cirrhosis/failure
What are less common causes of transudates?
- Hypoalbuminaemia
- Peritoneal dialysis
- Hypothyroidism
- Nephrotic syndrome
- Mitral stenosis
What are rare causes of transudates?
- Constrictive pericarditis
- Urinothorax
- Meigs’ syndrome
- Superior vena cava obstruction
What are exudates generally caused by?
Local problems e.g. infection, lung cancer
What are common causes of exudates?
- Infection
- Malignancy
- Parapneumonic effusions
- TB
What are less common causes of exudates?
- Pulmonary
- Rheumatoid arthritis
- Other autoimmune pleuritic
- Benign asbestos effusion
- Pancreatitis
- MI
- Post-coronary artery bypass graft