Misc
Identify symptoms of pl. effusion
Dyspnoea
pleuritic chest pain
cough
What mechanism causes transudate effusion?
Increased hydrostatic pressure OR
Decreased oncotic pressure
RESULT - fluid leaks into pl. space
What mechanism causes exudate effusion?
Increased capillary permeability OR
Impaired lymphatic drainage
RESULT - protein rich fluid accumulates in pl. space
identify 3 features of pl. effusion on an X-ray
- opacity where fluid is - normally at bases if standing position
- lost costophrenic angle
- lung collapse
- deviated trachea
Define a pleural effusion.
Where excess fluid accumulates in the pleural cavity
How much fluid is in the pl. cavity normally?
Normal - 10-20ml
Seen on Xray ~ 500ml
What types of fluid can be seen in pl. effusion?
- exudate - protein rich
- transudate - low protein content
- chylous effusion - contents of lymphatics
- blood effusion - haemothorax
GENERALLY, how would you manage a pl. effusion.
2 ways
- Thoracentesis - Drain it to relieve symptoms
- Treat the underlying cause
- CHF - diuretics, reduce Na+ consumption
- pneumonia/TB - surgery
List 3 complications of pl. effusion
- ATELECTASIS - lung collapse
- Fibrosis / scarring
- Infection (empyema)
What 4 forces cause the increased fluid in the pl. space?
- Increased hydrostatic pressure
- decreased oncotic pressure
- increased capillary permeability
- Lymphatic obstruction
How can pl. effusion lead to atelectasis
By mechanical Compression:
As the effusion increases, the fluid exerts pressure on the adjacent lung, compressing it >> reduced lung expansion. This can lead to the collapse of part or all of a lung aka atelectasis
Clinical distinguishing factors of Exudate vs Transudate (light criteria)
[fluid protein] : [serum protein] > 0.5 = exudate, < 0.5 = transudate
[fluid LDH] : [serum LDH] > 0.6 = exudate, < 0.6 = transudate
or
[fluid LDH] > [2/3 Normal upper limit of serum LDH]
Identify 3 key physical exam findings in pl. effusion
- stony dullness on percussion - there's fluid
- decreased breath sounds
- decreased tactile fremitus/vocal resonance
What conditions can lead to transudate pl. effusion? How?
- CHF - blood backup causes increased hydrostatic pressure = fluid flows out of capilaries
- liver cirrhosis - causes decreased protein content = decreased oncotic pressure
- Nephrotic syndrome = causes loss of protein content in urine = decreased oncotic pressure
What conditions cause exudate pl. effusion?
- malignancy >> inflamation or lymphatic obstruction
- inflammatory conditions eg - pneumonia
What investigations would you do following discovery of pl. effusion?
- sputum culture - gram stain
- biochemistry on pl fluid vs serum ratio - assess proteins, glucose, amylase, lipids
- cytology - neutrophillia (inf.), lymphocytosis (TB/Conn.T dissorders), eryhrocytes, atypical mesothelial or epithelial cells (cancer)