Antibiotic management of complicated parapneumonic effusion or empyema complicating hospital-acquired or ventilator-associated pneumonia
Adults and children with hospital-acquired pneumonia (HAP) or ventilator-associated pneumonia (VAP) who develop a complicated pleural effusion (parapneumonic effusion) or empyema require:
- intravenous antibiotics
- pleural fluid sampling and drainage.
For the definitions of complicated parapneumonic effusion or empyema, and a summary of management, see Definitions and management of parapneumonic effusion and thoracic empyema.
The aetiology is similar to community-acquired parapneumonic effusion or empyema. However, Pseudomonas aeruginosa and other resistant gram-negative bacteria are important potential pathogens, and Staphylococcus aureus (including methicillin-resistant S. aureus [MRSA]) is more commonHassan, 2021.
Collect pleural fluid samples to analyse for:
- biochemistry (which may include pH, lactate dehydrogenase [LDH], protein and glucose)
- cytology
- culture.
Culturing pleural fluid in blood culture bottles, in addition to standard culture, can increase microbial yieldMenzies, 2011. Other investigations, such as nucleic acid amplification tests (NAAT) (eg polymerase chain reaction [PCR]), are sometimes performed on pleural fluid samples.
If available, use the results of microbiological investigations to guide antibiotic therapy, noting that in adults these infections are typically polymicrobial. In children, if an anaerobic pathogen is identified by culture, the infection is often polymicrobial – seek expert advice on adjusting therapy.
Culture results are often negative because of preceding antimicrobial therapy for pneumonia, but also because it is possible that most organisms reside in pleural tissue rather than pleural fluidLee, 2018Psallidas, 2018. The role of routine pleural biopsy remains unclear outside of tuberculosisShaw, 2018. If microbiological results are not available or are negative, use the empirical regimens below.