Pleural diseases Flashcards
What is the structure of normal pleura
Glistening, smooth, thin membrane covers thoracic cavity & lung
Outer layer : Parietal Pleura
Inner Layer : Visceral Pleura
In between : Pleural fluid
What is pleural fluid
Straw coloured
0.26ml/kg/cavity
Used for filtration
Protein - 1.5-2g/dl
Few cells : macrophages, lymphocytes, mesothelial cells
What are the differerent pleural problems
Collection of fluid: Pleural effusion
Collection of Air : Pneumothorax
Pleural malignancy : Mesothelioma
What is the pathogenesis of pleural effusion
Collection of fluid in the pleural space
Imbalance between production and absorption
Absorption : Pleural lymphatics in the parietal pleura
What are the different types of effusion
Transudate- Non- inflammatory
Exudate- Inflamatory
Protein content of exudate- 3g/dl
What is LIGHTS criteria for pleural effusion
Protein : Pleural fluid /serum fluid ratio > 0.5
LDH : Pleural fluid /serum fluid ratio > 0.6
Pleural fluid LDH > 2/3 rd ULN serum LDH
What are some common causes of transudates
Left ventricular failure
Livercirrhosis
What are the less common causes of tansudates
Hypoalbuminaemia
Peritoneal dialysis
Hypothyroidism
Nephrotic syndrome
Mitral stenosis
What are the rare causes of transudate
Constrictive pericarditis
Urinothorax
Meigs’ syndrome
What are the comon causes of exudate
Malignancy
Parapneumonic effusions
Empyema
Tb
What are the less common causes of exudates
Pulmonary embolism
Connective tissue disease
Benign asbestos pleural effusion
Pancreatitis
Post-myocardial infarction
Post-coronary artery bypass graft
Haemothorax, chylothorax
What are the rare causes of exudate
Yellow nail syndrome (and other lymphatic disorders eg, lymphangioleiomyomatosis)
Drugs (see table 2)
Fungal infections
What are the investigations for pleural effusion
US : more sensitive than CXR , mark site for aspiration, assess pleura, bedside
CXR : accessible , easy to interpret
CT Thorax : Complex effusions , visualising the pleura , vascular and mediastinal structures
How would you analyse pleural fluid
Aspiration : simple and safe, trained operator
Inspect the fluid
PH ( bedside ABG machine ), biochemistry, microbiology and cytology
What are the management options for pleural effusion
PH < 7.2 with pneumonia, pus or blood -> chest drain
Transudate: treat underlying cause, may not need CT imaging
Exudate : Unless cause identified will need further investigation for eg further imaging , and or pleural biopsy