Abstract
Parapneumonic effusion and empyema are rising in incidence worldwide, particularly
in association with comorbidities in an aging population. Also driving this change
is the widespread uptake of pneumococcal vaccines, leading to the emergence of nonvaccine-type
pneumococci and other bacteria. Early treatment with systemic antibiotics is essential
but should be guided by local microbial guidelines and antimicrobial resistance patterns
due to significant geographical variation. Thoracic ultrasound has emerged as a leading
imaging technique in parapneumonic effusion, enabling physicians to characterize effusions,
assess the underlying parenchyma, and safely guide pleural procedures. Drainage decisions
remain based on longstanding criteria including the size of the effusion and fluid
gram stain and biochemistry results. Small-bore chest drains appear to be as effective
as large bore and are adequate for the delivery of intrapleural enzyme therapy (IET),
which is now supported by a large body of evidence. The IET dosing regimen used in
the UK Multicenter Sepsis Trial -2 has the most evidence available but data surrounding
alternative dosing, concurrent and once-daily instillations, and novel fibrinolytic
agents are promising. Prognostic scores used in pneumonia (e.g., CURB-65) tend to
underestimate mortality in parapneumonic effusion/empyema. Scores specifically based
on pleural infection have been developed but require validation in prospective cohorts.
Keywords
parapneumonic effusion - pleural infection - empyema - intrapleural enzyme therapy
