From the Guidelines
Pneumonia can lead to empyema when bacteria from a lung infection spread to the pleural space, causing a collection of pus between the lung and chest wall, and this progression can be prevented with early recognition and management of pneumonia. The process of developing empyema from pneumonia typically begins with the production of excess pleural fluid due to inflammation caused by the lung infection. Initially, this fluid may be sterile, known as a parapneumonic effusion, but if bacteria invade this space, the fluid becomes infected and transforms into pus, defining empyema 1.
Key Factors in Empyema Development
- The presence of organisms identified by Gram stain or culture from non-purulent pleural fluid samples indicates that pleural infection is established and should lead to prompt chest tube drainage 1.
- Pleural fluid pH should be assessed in all non-purulent, possibly infected effusions, and a pH <7.2 indicates chest tube drainage is required 1.
- Risk factors for developing empyema from pneumonia include delayed or inadequate antibiotic treatment, immunocompromised states, and underlying lung diseases.
- Common causative organisms include Streptococcus pneumoniae, Staphylococcus aureus, and anaerobic bacteria.
Treatment and Management
- Treatment requires both appropriate antibiotics (often broad-spectrum initially, then targeted based on culture results) and drainage procedures ranging from thoracentesis to surgical interventions, depending on the empyema's stage and complexity 1.
- All patients should receive antibiotic therapy as soon as pleural infection is identified, and where possible, antibiotics should be chosen based on the results of pleural fluid culture and sensitivities 1.
- The choice of antibiotics should cover community-acquired bacterial pathogens and anaerobic organisms, with broader spectrum cover for hospital-acquired empyema 1.
Prevention and Early Intervention
- Early recognition and management of pneumonia can prevent the serious complication of empyema.
- Prompt treatment with appropriate antibiotics and drainage procedures can significantly improve outcomes in patients with empyema.
- It is crucial to monitor patients with pneumonia closely for signs of pleural infection and to intervene early if complications arise.
From the Research
Pneumonia and Empyema
- Pneumonia can lead to empyema, which is a complication of pneumonia or lung abscess, as stated in 2 and 3.
- The development of empyema from pneumonia can be attributed to the diffusion of bacteria from the lungs into the pleural space, leading to infection and inflammation, as mentioned in 4.
- Parapneumonic effusions, which are associated with pneumonia, can progress to empyema through a series of stages, including exudative, fibrinopurulent, and organizing stages, as described in 4.
- The bacteriology of empyemas that occur in association with lung infections is often polymicrobial and mixed, containing multiple species of both aerobic and anaerobic bacteria, as noted in 2.
Pathophysiology
- The pathophysiology of parapneumonic effusion development involves direct invasion of bacteria, cascade of inflammatory events, and bacteriologic virulence features, as well as patient factors and comorbidities, as discussed in 4.
- The evolution of parapneumonic effusion can be divided into three progressive stages, which can help categorize effusions into groups in order to evaluate the risk of a complicated course requiring intervention, as mentioned in 4.
Relationship between Pneumonia and Empyema
- Pneumonia is a significant risk factor for the development of empyema, with an incidence of 52% in patients with post-pneumonia syndrome, as reported in 3.
- Empyema has traditionally been considered a surgical disease, but with advances in minimally invasive procedures, medical management is now preferred over surgery for many cases of empyema, as stated in 3.