From the Guidelines
Empyema is diagnosed when there is pus in the pleural space, characterized by specific criteria, including purulent pleural fluid, positive pleural fluid culture, or positive pleural fluid Gram stain, as well as biochemical parameters such as pleural fluid pH less than 7.2 1. The diagnosis of empyema requires a thorough evaluation of the pleural fluid, including its appearance, biochemical parameters, and microbiological analysis.
- The presence of frank pus in the pleural space is a definitive indicator of empyema.
- A positive pleural fluid culture or Gram stain also supports the diagnosis of empyema.
- Biochemical parameters, such as pleural fluid pH less than 7.2, can help identify patients who require chest tube drainage 1. The management of empyema involves a combination of antibiotics and drainage procedures, with the goal of preventing progression to the organizing phase and reducing morbidity and mortality.
- Antibiotics should be targeted towards the causative organism, which is commonly Streptococcus pneumoniae, Staphylococcus aureus, or anaerobes.
- Drainage options range from thoracentesis for simple cases to chest tube placement, intrapleural fibrinolytics, video-assisted thoracoscopic surgery (VATS), or open thoracotomy for more complex cases. Early diagnosis and intervention are crucial in the management of empyema, as delayed treatment can lead to increased morbidity and mortality 1.
- The use of biochemical tests, such as pleural fluid pH, can help guide decisions regarding the need for pleural fluid drainage.
- Molecular analysis, such as nucleic acid or antigen detection methods, can also be useful in identifying the causative organism and guiding antibiotic therapy 1.
From the Research
Criteria for Empyema
The criteria for empyema are as follows:
- Size of the pleural effusion: greater than or equal to 1/2 of the hemithorax 2
- Presence of loculations 2
- Pleural fluid pH: less than 7.20 2
- Pleural fluid glucose: less than 60 mg/dl 2
- Positive pleural fluid Gram stain or culture 2
- Purulent appearance of the pleural fluid 2
Diagnosis and Treatment
Diagnosis of empyema involves imaging studies such as chest radiograph, ultrasound, and computed tomography, as well as pleural fluid analysis 2. Treatment includes the use of appropriate antibiotics, nutritional support, and drainage of the pleural space through methods such as therapeutic thoracentesis, tube thoracostomy, intrapleural fibrinolytics, thoracoscopy, or thoracotomy with decortication 2.
Antibiotic Penetration
The penetration of antibiotics into empyemic pleural fluid can vary, with penicillin and metronidazole showing the most rapid equilibration 3. The choice of antibiotic should take into account the degree of penetration into the pleural space 3.
Note: The study from 1976 4 is not relevant to the topic of empyema.