Pleural Disorders (Harrisons 263) Flashcards
Transudative pleural effusion occurs when…
…SYSTEMIC factors influencing pleural fluid are altered.
Exudative pleural effusion occurs when…
…LOCAL factors influencing pleural fluid are altered.
Most common cause of pleural effusion
Left ventricular failure
Why does left ventricular failure cause pleural effusion?
Increased amounts of fluid in the interstitial spaces of lungs exit across the visceral pleura, overwhelming the lymphatic system’s capacity to remove fluid
How can we determine that a pleural effusion is secondary to heart failure?
A pleural fluid BNP of > 1500 is “virtually diagnostic”
Hepatic hydrothorax
Direct movement of peritoneal fluid through small openings in the diaphragm into the pleural space
Parapneumonic effusions
Associated with bacterial pneumonia, lung abscess, or bronchiectasis
Most common cause of EXUDATIVE pleural effusion in the US
If the fluid in a parapneumonic effusion separates the lung from chest wall by > 10mm…
…a therapeutic thoracentesis should be performed
Factors that indicate the need for a procedure more invasive than thoracentesis, in order of increasing importance:
1) Loculated pleural fluid
2) Pleural fluid pH < 7.2
3) Pleural fluid glucose < 60 mg/dL
4) Positive Gram stain or culture of pleural fluid
5) Presence of gross pus in the pleural space
How is a malignant effusion diagnosed?
Cytology of the pleural fluid
Mesotheliomas are…
primary tumors of the mesothelial cells that line the pleural cavities.
What’s the most common factor in mesothelioma?
Asbestos exposure
The most commonly overlooked diagnosis of a patient with a pleural effusion:
pulmonary embolism
Jeopardy!
A very common cause of pleural effusion in many parts of the world, but relatively uncommon in the US.
What is tuberculosis?
How do we diagnose a tuberculous pleuritis?
high levels of TB markers in the pleural fluid
