Parapneumonic effusions are effusions that occur in the pleural space adjacent to bacterial pneumonia.
- Uncomplicated: exudative, normal pH/glucose and negative gram stain/culture
- Complicated: exudative, low pH (<7.20), a low glucose and and often loculated
- Empyema: pus and organism visible on gram stain, although cultures maybe negative
Indications for Thoracentesis
- free flowing, layers > 25mm on a lateral decubitus film or CT
- associated with thickened parietal pleura on CT scan, a finding suggestive of empyema
- clearly delineated by US
Pleural Fluid Studies
- See here for our previous review of pleural fluid studies
- Large loculated or complicated parapneumonic effusion: chest tube
- Empyema: chest tube and VATS with debridement +/- decortication
- Same bugs that cause pneumonia: strep pneumo most common. Others include Strep milleri, Staph aureus and Enterobacteriaceae
- Anaerobic bacteria have been cultured in 36 to 76% of empyema; Fusobacterium, Prevotella, Peptosteptococcus , Bacteroides.
- Always cover for anaerobes (hard to culture so treat empirically)
UTSW Internal Medicine