Necrotising Fasciitis in the ST3 Plastics Interview
How to answer a necrotising fasciitis scenario in the ST3 Plastic Surgery interview: clinical diagnosis, LRINEC as an adjunct, Sepsis Six, and the debridement plan.
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Necrotising fasciitis is the archetypal ST3 plastics emergency station: a life-threatening diagnosis you must make clinically, resuscitate for, and take to theatre — while talking through the operation like someone who has actually stood at the table.
How the scenario tends to open
A typical stem: a diabetic inpatient develops a rash spreading rapidly over hours, and you are asked to review. Uncontrolled diabetes plus rapid progression is the combination doing the work: the examiner wants necrotising fasciitis named early, framed as a clinical diagnosis and a surgical emergency.
The approach that scores
Anchor the answer on urgency: this is a clinical diagnosis, and no score or scan should delay surgery. Then structure it the way the station flows — assessment, resuscitation, definitive surgery, post-operative plan — keeping each stage concrete.
- Assess with A–E, looking for rapid spread beyond previous markings, pain out of proportion, systemic toxicity; blistering signals advanced disease.
- Investigations support but never gate: bloods including lactate, group and save; the LRINEC score is an adjunct only (6–8 intermediate risk, above 8 high risk), and HbA1c matters in this patient.
- Resuscitate with the Sepsis Six inside the hour, and give broad-spectrum antibiotics per trust guidelines — classically a triple regimen along the lines of benzylpenicillin, clindamycin, and a broad-spectrum agent, refined with microbiology.
- Mobilise theatre in parallel: consultant plastic surgeon on call, anaesthetist, CEPOD, microbiology for urgent Gram stains; consent (or consent form 4 if the patient lacks capacity) and speak to the next of kin.
- Describe the operation like a surgeon: radical debridement of all unhealthy tissue back to bleeding, viable margins — the classic dishwater fluid confirming the diagnosis — with tissue for microbiology and histology, thorough washout, and dressings or negative-pressure therapy.
- Plan the aftercare: intensive care post-operatively, ongoing antibiotics tailored to results, and a planned second look within 48 hours — earlier if the patient deteriorates.
Where candidates lose marks
Waiting for imaging or an LRINEC threshold before calling theatre inverts the logic of the disease. At ST3 level the surgical detail is also part of the test: a candidate who cannot outline the debridement, the second look, and the intensive-care plan sounds like an observer rather than the registrar who will hold the retractor. If the examiner adds a deterioration twist — rising vasopressors, dusky wound edges hours after surgery — the answer is a return to theatre, not more monitoring.
Rehearse it
Reading about necrotising fasciitis is the easy half. Rehearse this exact scenario out loud, on the clock, with an AI examiner — this scenario is in Reviva’s library, with feedback marked the way the panel marks. Or start with the wider format in the st3 plastics clinical station guide.
Frequently asked questions
- Is the LRINEC score required to diagnose necrotising fasciitis?
- No — necrotising fasciitis is a clinical diagnosis and LRINEC is an adjunct only (6–8 intermediate risk, above 8 high). No score or scan should delay surgical debridement.
- What antibiotics are used for necrotising fasciitis?
- Broad-spectrum cover per your trust guidelines — classically described as triple therapy such as benzylpenicillin, clindamycin, and a broad-spectrum agent — narrowed once Gram stains and cultures return.
- Why is a second-look operation planned within 48 hours?
- Because residual infected foci are common after the first debridement. A planned return within 48 hours — earlier if the patient deteriorates — is part of the standard of care and belongs in your answer.
Sources. Grounded in the standard emergency management of necrotising soft-tissue infection (clinical diagnosis, LRINEC as adjunct, Sepsis Six, staged debridement) as rehearsed in Reviva’s ST3 plastics scenario. Educational only — follow your local policies.