Synopsis
Use pleural-fluid appearance, immediate pH and imaging to identify infected pleural collections that need drainage, then integrate antibiotics, drain care, intrapleural therapy and timely surgery under current BTS guidance and the local pleural-service protocol.
- Frank pleural pus establishes empyema and should prompt intercostal drainage when a safe ultrasound window exists.
- For non-purulent fluid, measure pH immediately on a blood-gas analyser: pH 7.20 or below indicates high risk and usually warrants drainage.
- At pH 7.21 to 7.39, LDH 900 IU/L or above plus large volume, glucose 4.0 mmol/L or below, septations or CT pleural enhancement supports drainage.
Key red flags
Reduced breath sounds and expansion, mediastinal displacement or ultrasound septations suggest substantial burden. Respiratory compromise or haemodynamic effect requires urgent respiratory and procedural review.
Investigation priorities
Confirm fluid, estimate depth and volume, identify septations and mark a safe aspiration or drain site in real time.
Management branches
Pneumonia with an accessible pleural effusion requiring diagnostic sampling.
- Perform ultrasound-guided aspiration, identify frank pus and send appropriate microbiology; for non-purulent fluid obtain immediate uncontaminated pH.
- Insert an image-guided intercostal drain for pus or pH 7.20 or below, assuming a safe accessible volume; at pH 7.21 to 7.39 integrate LDH, glucose, size, septations, CT enhancement and clinical course.
Key medicines
Co-amoxiclavUse the locally approved intravenous or oral adult regimen, adjusted for renal function and severity; verify current BNF and pleural-infection policy.
Piperacillin with tazobactamLocal intravenous regimen with renal adjustment and any approved extended-infusion approach; confirm current BNF.