From the Research
Pleural effusions of small to moderate size, typically less than 300-500 mL in volume, can often resolve on their own without intervention. The body's natural mechanisms can reabsorb this fluid through the pleural lymphatics, which normally clear 0.1-0.2 mL/kg/hour of fluid 1. Resolution typically depends on treating the underlying cause rather than the effusion itself. For example, effusions due to heart failure often resolve with diuretics like furosemide 20-40 mg daily, while parapneumonic effusions may clear with appropriate antibiotics for the pneumonia. Some key points to consider in the management of pleural effusions include:
- Observation is reasonable for asymptomatic patients with small effusions (occupying less than one-third of the hemithorax on imaging) 1.
- Larger effusions (>1000 mL), those causing significant symptoms like dyspnea, or effusions that persist beyond 2-4 weeks generally require therapeutic intervention such as thoracentesis 1.
- The use of point-of-care ultrasound can help guide thoracentesis and reduce complications 1.
- The body's ability to reabsorb pleural fluid diminishes when the rate of fluid accumulation exceeds the lymphatic drainage capacity or when the underlying condition continues to drive fluid production. It is essential to note that the management of pleural effusion should be guided by the underlying cause and the patient's symptoms, rather than the size of the effusion alone 2, 1.