Parapneumonic effusion and empyema.

Parapneumonic effusions account for about one third of all pleural effusions. Approximately 40% of patients with pneumonia develop a concomitant effusion, which is associated with an increased morbidity and mortality. In order to select the most appropriate therapy for the individual patient, the effusion should be categorized as being in the exudative, fibropurulent, or organizational stage, and all necessary information should be compiled to decide whether the effusion is likely to take an uncomplicated or a complicated course. There is a considerable variation in the aggressiveness and course of parapneumonic effusions, and, therefore, the spectrum of the appropriate therapy may vary from a conservative approach in uncomplicated effusions to aggressive surgical intervention in advanced multiloculated empyemas. This review discusses current diagnostic and therapeutic options and offers guidelines for treating the various stages of parapneumonic effusions and empyemas.