Pleural empyema

Pleural empyema is a collection of pus in the pleural cavity. It is caused by microorganisms, usually bacteria. It often happens in the context of a pneumonia, injury, or chest surgery. It is one of the various kinds of pleural effusion. Pleural empyema contains three stages: exudative: when there is an increase in pleural fluid with or without the presence of pus; fibrinopurulent: when fibrous septa form localized pus pockets, and the final organizing stage: when there is scarring of the pleura membranes with possible inability of the lung to expand. Simple pleural effusions occur in up to 40% of bacterial pneumonias. They are usually small and resolve with appropriate antibiotic therapy. However, if an empyema develops additional intervention is required.