[Parapneumonic pleural effusions: Epidemiology, diagnosis, classification and management].

Parapneumonic pleural effusions represent the main cause of pleural infections. Their incidence is constantly increasing. Although by definition they are considered to be a "parapneumonic" phenomenon, the microbial epidemiology of these effusions differs from pneumonia with a higher prevalence of anaerobic bacteria. The first thoracentesis is the most important diagnostic stage because it allows for a distinction between complicated and non-complicated parapneumonic effusions. Only complicated parapneumonic effusions need to be drained. Therapeutic evacuation modalities include repeated therapeutic thoracentesis, chest tube drainage or thoracic surgery. The choice of the first-line evacuation treatment is still controversial and there are few prospective controlled studies. The effectiveness of fibrinolytic agents is not established except when they are combined with DNase. Antibiotics are mandatory; they should be initiated as quickly as possible and should be active against anaerobic bacteria except for in the context of pneumococcal infections. There are few data on the use of chest physiotherapy, which remains widely used. Mortality is still high and is influenced by underlying comorbidities.