A pleural effusion is fluid collecting between the lung and the chest wall. Fluid from heart failure is usually a transudate, while infection or cancer usually causes an exudate, and Light's criteria help tell them apart.
Key symptoms
- Shortness of breath
- Sharp chest pain on breathing in
- Dry cough
- Symptoms of the cause: leg swelling, fever, weight loss
What you find on exam
- Stony dullness to percussion
- Reduced breath sounds and tactile fremitus
- Trachea pushed away from a large effusion
- Signs of heart failure, liver disease or cancer
Tests
- Chest X-ray: blunted costophrenic angle; bedside ultrasound
- Thoracentesis guided by ultrasound
- Light's criteria: pleural fluid protein and LDH compared with blood
- Fluid cell count, glucose, pH, Gram stain, culture and cytology
Treatment basics
- Treat the cause: diuretics for heart failure, antibiotics for infection
- Therapeutic thoracentesis for breathlessness, usually no more than 1.5 L at a time
- Chest tube for empyema or a complicated effusion
- Pleurodesis or an indwelling pleural catheter for cancer effusions that come back
Red flags
- Severe breathlessness or low oxygen
- Fever with an effusion (possible empyema)
- Shifted trachea with low blood pressure
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Sources: NCCPA PANCE Content Blueprint; NBOME COMLEX-USA clinical presentations; AAMC Core Entrustable Professional Activities (Core EPAs). Written by Making Synapses. Making Synapses is not affiliated with these organizations.