Pleural effusion and empyema — branching viva

Opening

Examiner: A 4-year-old admitted with a right lower lobe pneumonia is still febrile after three days of intravenous antibiotics and now has pleuritic chest pain and stony dullness at the right base. What is going on and what do you do? [1]

Candidate: A pneumonia that fails to improve after two to three days of appropriate antibiotics has a complication until proven otherwise, and the commonest is a parapneumonic effusion, possibly an empyema. The new pleuritic pain, stony dullness and reduced breath sounds fit fluid at the base. I would reassess her septic state and oxygenation, continue intravenous antibiotics, give analgesia, and arrange an urgent chest ultrasound to confirm and stage the collection. [1] [2]

Branch 1 — imaging and staging

Examiner: Why an ultrasound rather than a chest X-ray or a CT? [1]

Candidate: The chest radiograph will show an opacity but cannot reliably tell simple fluid from loculated pus, and it can overcall consolidation as effusion. Ultrasound confirms the fluid, estimates its size, shows whether it is anechoic and free-flowing or septated and loculated, and marks a safe drainage site — exactly the information that guides whether and how to drain. CT is not routine; I would reserve it for atypical or non-resolving disease or a suspected underlying lesion. [1] [2]

Examiner (probe): If I aspirate fluid, what tests do I send and what does a low pH mean? [4]

Candidate: I would send Gram stain, culture and pneumococcal PCR, and on non-purulent fluid measure pH, glucose and LDH and apply Light's criteria. A low pH, below about 7.2, with a low glucose and a high LDH marks a complicated parapneumonic effusion — the fibrinopurulent stage — which will not settle on antibiotics alone and needs drainage. Frank pus is diagnostic of empyema and needs no biochemistry. [4] [1]

Branch 2 — the drainage decision

Examiner: The ultrasound shows a large loculated collection. How will you drain it? [3]

Candidate: For a loculated collection or empyema I would insert an ultrasound-guided intercostal chest drain and give intrapleural fibrinolytics, such as urokinase, to break down the fibrin septations. The alternative is primary VATS to break down the loculations under vision. Randomised trials show the two are clinically equivalent, and I would choose fibrinolytics first-line because they are less invasive and cheaper, keeping VATS for failure or where surgery is readily preferred. [3] [5]

Examiner (probe): What is the evidence that fibrinolytics and surgery are equivalent? [3]

Candidate: The Sonnappa 2006 randomised trial compared intrapleural urokinase with primary VATS and found similar clinical outcomes and length of stay, with urokinase substantially cheaper. The St Peter trial found no advantage of primary thoracoscopy over drainage with fibrinolysis, and the Cochrane review concluded surgical and non-surgical approaches give broadly comparable outcomes, so the choice can follow local expertise and resources. [3] [5]

Branch 3 — failure and prognosis

Examiner: After 72 hours with a drain and fibrinolytics she is still septic and the lung looks trapped. Next step? [2]

Candidate: That is treatment failure, so I would escalate to surgery — VATS to break down loculations and evacuate the pus, with decortication if there is an organised fibrous peel trapping the lung — while ensuring antibiotics are optimised and involving the intensive care team for her sepsis. I would also reconsider the microbiology, including aggressive organisms such as Staphylococcus aureus and the possibility of necrotising pneumonia. [2] [1]

Examiner (probe): Her parents ask about her lungs in the long run. What do you say? [2]

Candidate: I would reassure them that the prognosis is excellent: despite a long and demanding course, the great majority of children with empyema recover completely, and follow-up shows that long-term lung function and chest imaging return to normal in most. We will review her with a chest radiograph after a few weeks to confirm resolution. [2]

Close

Examiner: Summarise your safe approach to the child with a parapneumonic effusion in one line. [1]

Candidate: In any child whose pneumonia is not improving, image with ultrasound rather than waiting, give antibiotics to everyone, drain the loculated or purulent collection with fibrinolytics, escalate to surgery for failure, and reassure the family that the long-term outlook is excellent. [1] [3]