Diseases of the Pleura Flashcards
will excess fluid in the pleural space tend to move into the lungs or across the parietal pleura in to the chest wall? why?
into the lungs.
as the pulmonary arterial pressure is smaller than the systemic arterial pressure so fluid will tend to move into arteries in the lungs
why is the fact that the pleura extends down over the liver and up over the first rib important clinically?
because a liver biopsy may puncture the pleura at the base of the lung or a when putting a cannula into a subclavicular vein.
what is a pleural effusion?
a collection of fluid in the pleural space
when might a pleural effusion be asymptomatic?
is it is small and accumulates slowly
what are some symptoms of a pleural effusion?
increasing breathlessness pleuritic chest pain dull ache dry cough weight loss, malaise, fevers, night sweats
what are the different causes of pleuritic chest pain from a pleural effusion?
inflammatory- occurs early on and may improve with fluid accumulating
malignant- will get progressively worse
what are the signs of a pleural effusion?
- decreased chest expansion
- stony dullness to percussion
- decreased breath sounds
- band of bronchial breathing above the collection of fluid
- decreased vocal resonance
what is are some other signs that might go along with a pleural effusion?
clubbing tar staining of fingers increased JVP trachea away from large effusion peripheral oedema (heart failure) cervical lymphadenopathy (malignancy)
what are the two types of pleural effusion?
transudates
exudates
what causes a transudate PE?
An imbalance of hydostatic forces influencing the formation and absorption of pleural fluid.
what causes an exudate PE?
an increased permeability of pleural surfaces and/or local capillaries
are transudate usually unilateral or bilateral?
bilateral
are exudates usually unilateral or bilateral?
unilateral
is capillary permeability affected in transudate PE?
no
what is the protein content of a transudate?
<30g/l
what is the protein content of an exudate?
> 30g/l
what are the very common causes of transudates?
left ventricular failure
liver cirrhosis
hypoalbuminaemia
peritoneal dialysis
what is peritoneal dialysis?
a form of dialysis in which fluid the filtration of the blood is done through the peritoneum
what are the less common causes of transudates?
- Hypothyroidism
- Nephrotic syndrome
- Mitral stenosis
- Pulmonary embolism (2/3rds exudates)
what is mitral stenosis?
a narrowing of the mitral valve between the left atrium and ventricle, decreases blood flow through the valve
what are the common causes of exudate?
-malignancy (lung, breast, mesothelioma, mets)
what are the less common causes of exudates?
- Pulmonary embolism/infarction
- Rheumatoid arthritis
- Autoimmune diseases (SLE, polyarteritis)
- Benign asbestos effusion
- Pancreatitis
- Post-myocardial infarction/cardiotomy syndrome
what is cardiotomy syndrome?
an immune response following an operation with an incision in the pericardium
what are the rare causes of exudates?
yellow nail syndrome
certain drugs eg. nitrofurantoin, penicillamine
what are the rare causes of transudate?
constrictive pericarditis
ovarian hyperstimulation syndrome
Meig’s syndrome
are investigations usually required for transudates?
no
why are investigations not usually needed for transudates?
because clinical picture is usually characteristic
when are transudates investigated?
when there are unusual features or a failure to respond to treatment
what investigation is carried out to confirm the presence of a PE?
CXR
what volume of fluid is required before a PE is detectable?
200ml
what is a contrast enhanced CT used for when investigating a PE?
differentiation between malignant and benign disease
what signs of a contrast CT are indicative of a malignant cause of PE?
- nodular pleural thickening -mediastinal pleural thickening
- parietal pleural thickening >1cm -circumferential pleural thickening
- other malignant manifestations in lung/liver
what are the investigations carried out for a PE?
CXR
contrast enhanced CT
aspiration
biopsy
what are the potential complications of a pleural aspiration?
Pneumothorax (if air gets in through) needle
Empyema (if needle is dirty)
Pulmonary oedema (if fluid id drained too fast)
Vagal reflex (if pleura not adequately anaesthatised)
Air embolism
Tumour cell seeding
Haemothorax (if blood clotting is compromised)
if the fluid from a pleural aspiration is foul smelling what is it indicative of?
anaerobic empyema
if the fluid from a pleural aspiration contains pus what is it indicative of?
empyema
if the fluid from a pleural aspiration contains food particles what is it indicative of?
oesophageal rupture
if the fluid from a pleural aspiration is milky what is it indicative of?
chylothorax (usually lymphoma)
if the fluid from a pleural aspiration is blood stained what is it indicative of?
possible malignancy
if the fluid from a pleural aspiration blood what is it indicative of?
haemothorax (maybe from trauma)
what are the tests done on fluid from pleural aspiration in the ward?
look and smell
blood gas analyser (not if pus though)