Pleural diseases Flashcards
what colour is healthy pleural fluid
what is the normal volume of pleural fluid?
Straw coloured (resembles plasma) and zero odor
15-20 mls
how is a pleural fluid made?
where is this process?
(and inner) but due to balance forces, it’s parietal that does most
filtration which happens from the parietal pleura
how much protein is in the pleura?
1.5-2g of protein
what cells can you find within the pleura?
macrophages, lymphocytes filtered out from blood
mesothelial cells - shed from pleural space
what pressure is the pleural cavity at?
subatmospheric
-3=-5cm of water
the gradient is apex to base being more negativeive
name a few pleural problems
- pleural effusion - collection of fluid
- pneumothorax - a collection of air
- mesothelioma - pleural malignancy
what is blood in pleural area called?
haemothorax
what is pus in pleural space
empyema
describe pleural effision and how this occurs
a collection of fluid in the pleural space
caused by an imbalance between production and absorption (either excessive production or reduced absorption or a combination of both
when effusion collects in space there are 2 kinds (transudate; exudate)
protein contents of educate is 3/dl or more
what are the two kinds of pleural effusion
transudate - non-inflammatory
exudate - inflammatory
protein content of exudate is 3/dl or more
what is the protein content of exudate pleural effusion
3/dl or more/
whats is transudate pleural effision?
happens purely by the process of filtration = low protein content and is non-inflammatory
What is the lights criteria?
to differentiate transudate and exudate pleural effusion
protein: pleural fluid/serum fluid radio > 05
LDH pleural fluid /serium fluid ratio >0.6
pleural fluid LDH >2/3 ULN serum LDH
serum lactate dehydrogenase
what is serum lactate dehydrogenase?
an enzyme found in blood and bodily fluid
what does serum dehydrogenase compare?
pleural fluid to serum fluid levels
what usually causes transudates? pleura
Very Common causes - Left ventricular failure; liver cirrhosis
Less common causes: hypoalbuminaemia; peritoneal dialysis; hypothyroidism; nephrotic syndrome, mitral stenosis
rare causes: constrictive pericarditis urinothorax Meigs syndrome
Caused of pleural exudates
common causes - malignancy (pulmonary and non-pulmonary), Parapneumonic effusions empyema tuberculosis
less common causes: pulmonary embolism, connective tissue damage benign asbestos pleural effusion pancreatitis post-myocardial infarction post-coronary artery bypass graft haemothorax chylothorax
rare causes - Yellow nail syndrome (and other lymphatic disorders e.g. lymphangioleiomatosis) drugs fungal infections
investigations for pleural effusion
chest x-ray - accessible east to interpret (first one usually) (usually need 100-200ml to be seen)
Ultrasound: more sensitive than chest x-ray - mark site for aspiration bedside assessment
CT thorax - complex effusions visualising the pleura, vascular and mediastinal structure help also identify nodules.
what do you expect to see in xray pleural effusion
white out significant portion
concave upper margin

what do you expect to see ct image pleural effusion
grey crescent and dense white is squashed tissue between lung and fluid

how to analyse for pleural effusion
aspiration: simple and same, trained operation - ultrasound mark spot for aspiration (green needle) with or without anaesthetic.
inspect flood - if pus and blood obvious on inspection
ph (bedside ABG machine) biochemistry, microbiology and cytology
if ph less than 7.2 in prescence pneumonia - need for chest drain as likely this acidic fluid will eventially form pus
in aspiration of pleural fluid. what ph would need a chest drain and why?
if ph less than 7.2 in presence pneumonia - the need for chest drain as likely this acidic fluid will eventually form pus
what is good practice in aspirations for samples: where to send?
biology, microbiology and cytology
what does :
biochemistry
microbiology
cytology
do with aspiration samples
microbiology - sample will be cultured to find the presence of bacteria
biochemistry - process the protein levels: LDH, lactate dehydrogenase and glucose levels (narrow to find the cause)
cytologists - look for abnormal cells in the sample