Sepsis and Septic Shock: Sepsis Six, Source Control and NICE NG253

Sepsis in a surgical patient is life-threatening organ dysfunction caused by infection, and NICE NG253 replaced NG51 in November 2025 as the guideline that governs its early management. The answer the panel wants is structured: grade the risk with NEWS2, give antibiotics and a 250 ml fluid bolus within 1 hour if the risk is high, find and control the source, and escalate early. Everything else in a sepsis scenario hangs off those four moves.

Key takeaways

• NICE NG51 is withdrawn. NG253, published 19 November 2025, is the live sepsis guideline for people aged 16 or over.
• According to NICE NG253, a NEWS2 score of 7 or more suggests high risk of severe illness or death from sepsis, 5 or 6 suggests moderate risk, and a moderate-risk patient with a lactate over 2 mmol/L or acute kidney injury is treated as high risk.
• High-risk patients receive broad-spectrum intravenous antibiotics within 1 hour of the NEWS2 score being calculated, and a 250 ml crystalloid bolus over 10 to 15 minutes, repeated to 1,000 ml in total with reassessment after each bolus.
• The Sepsis Six is the UK Sepsis Trust's one-hour bundle for adults: inform a senior clinician, give oxygen if required, send bloods including cultures, give intravenous antibiotics and think source control, give intravenous fluids and consider vasopressors, and monitor.
• If a high-risk patient does not respond within 1 hour of any intervention, NG253 requires the senior clinical decision maker to attend in person, critical care to be consulted and the responsible consultant to be informed.
• Source control is the surgical contribution. A leak, a collection or an infected line does not resolve with antibiotics alone.

How do I recognise sepsis in a surgical patient?

Sepsis is recognised by asking 'could this be sepsis?' in any patient with a suspected infection and a change in physiology, then calculating NEWS2 to grade the risk. NG253 is explicit that the question comes first and the score second.

On a surgical ward the infection is usually in the chest, the urine, the wound, a collection, a cannula or central line, or an anastomosis that has leaked. Say the surgical sources out loud, because the panel is testing whether you think like a surgeon.

How does NICE NG253 grade the risk?

• NEWS2 of 7 or more: high risk of severe illness or death from sepsis
• NEWS2 of 5 or 6: moderate risk, reviewed with a venous lactate within 1 hour by a clinician at FY2 level or above
• Any single parameter scoring 3: a high-priority review by a clinician with acute-care competencies to decide the risk level
• Moderate risk plus a lactate over 2 mmol/L or acute kidney injury: manage as high risk
• Clinical judgement can raise the risk above the score, for example when the patient is deteriorating or a relative is worried

That said, NEWS2 can under-read a young, fit patient who compensates well. A surgical patient who looks unwell with a score of 4 still deserves the question and a lactate.

What is the immediate management from A to E?

Immediate management of suspected sepsis is ABCDE with the Sepsis Six delivered inside the first hour, started at the bedside while help is on the way. This is CCrISP stage one, and the panel expects you to say it in order.

• Airway: patent and protected; call an anaesthetist if the conscious level is falling
• Breathing: respiratory rate and saturations; oxygen to a target of 94 to 98%, or 88 to 92% if at risk of hypercapnic respiratory failure, as NG253 and the BTS guideline both state
• Circulation: wide-bore access, blood cultures and a blood gas with lactate and glucose, then a 250 ml crystalloid bolus over 10 to 15 minutes for high-risk patients
• Disability: AVPU or GCS, pupils and capillary glucose
• Exposure: temperature, the wound, every drain, every line, the calves and the abdomen

The Sepsis Six is the UK Sepsis Trust's bundle of six actions to complete within one hour: inform a senior clinician, give oxygen if required, send bloods including cultures, give intravenous antibiotics and think about source control, give intravenous fluids and consider vasopressors, and monitor with NEWS2, urine output and repeat lactate.

In practice the 2025 tool starts with informing a senior, which is a change from the older bundle. Candidates who recite the old six actions are describing a superseded version.

Which investigations change the decision in sepsis?

The investigations that change the decision are a venous or arterial blood gas with lactate and glucose, blood cultures taken before antibiotics without delaying them, and imaging aimed at the surgical source. NG253 asks for urine analysis and a chest X-ray in every patient with suspected sepsis.

Add a full blood count, urea and electrolytes, liver function, CRP and clotting, and culture anything that could be the source: urine, sputum, wound swabs, drain fluid and line tips. A CT of the abdomen and pelvis with contrast is the test for a suspected collection or anastomotic leak.

The UK Sepsis Trust tool asks for the lactate to be repeated at least hourly if the first value was raised. A lactate that is falling tells you the resuscitation is working; a lactate that is rising tells you to call.

What is the definitive management of surgical sepsis?

Definitive management of surgical sepsis is antibiotics that cover the likely source, fluid and vasopressors to restore perfusion, and physical control of the source. Antibiotics follow the local formulary and are reviewed once cultures return.

What do the fluid and blood pressure targets look like?

NG253 gives 250 ml boluses to a total of 1,000 ml with senior advice if the patient has not improved. Beyond that, the Surviving Sepsis Campaign 2026 guideline suggests at least 30 ml/kg of intravenous crystalloid in the first 3 hours for sepsis-induced hypoperfusion or septic shock, prefers balanced crystalloids to 0.9% saline, and recommends an initial mean arterial pressure target of 65 mmHg once vasopressors are needed.

Septic shock is sepsis in which the circulation fails despite fluid, so that vasopressors are needed to hold the blood pressure. That is a critical care decision, and NG253 asks for a shared decision about escalation before vasopressors are started.

What does source control mean on a surgical ward?

Source control means removing or draining the focus of infection: taking out an infected cannula or catheter, draining a collection under radiological guidance, washing out and defunctioning a leaking anastomosis, or debriding dead tissue. Antibiotics buy time; source control ends the sepsis.

When do I escalate, and who do I call?

Escalate at the moment of recognition, not after the bundle has failed. For a high-risk patient that means telling the registrar now, and involving the critical care outreach team or intensive care registrar in parallel.

• NEWS2 of 7 or more: registrar now, critical care outreach informed, consultant aware
• No response within 1 hour of any intervention in a high-risk patient: NG253 requires the senior clinical decision maker to attend in person, referral to or discussion with critical care, and the responsible consultant to be informed
• 1,000 ml of fluid given without improvement: senior advice under NG253; the UK Sepsis Trust tool says an ST3 or above should attend
• Any suspected surgical source: the operating consultant, because source control may mean theatre tonight

However senior the person you have called, keep reassessing. The patient's response to the first bolus, not the phone call, is what tells you whether the plan is working.

What does NICE NG253 change from NG51?

NG253 replaces the old red-flag and amber-flag lists with NEWS2 bands, ties the 1-hour antibiotic target to the moment the score is calculated, and reduces the initial bolus from 500 ml to 250 ml over 10 to 15 minutes. It also names the person who must come when the patient does not improve.

Interviewers know the guideline changed in November 2025. Naming NG253 and the 250 ml bolus shows your knowledge is current; naming NG51 suggests it is not.

How do I hand over a septic surgical patient?

Hand over in SBAR with numbers: the NEWS2 score and trend, the lactate and whether it is falling, what has been given and when, the suspected source, who has been told and what would trigger another call. One minute, and the plan is written before you leave.

What is the interviewer listening for?

• NG253 named, with the NEWS2 bands and the 1-hour targets stated as numbers
• The 250 ml bolus, reassessment after each, and the 1,000 ml point at which senior advice is mandatory
• A surgical differential for the source, and source control offered as a treatment rather than an afterthought
• Escalation that is early, named and persistent, including critical care
• Recognition that sepsis is a diagnosis you keep reviewing, with a repeat lactate and a repeat NEWS2

What are the common mistakes?

• Quoting NG51 or a 500 ml sepsis bolus, both of which are out of date
• Giving antibiotics without cultures, or delaying antibiotics to get cultures
• Fluid on repeat without reassessing, so that a patient in heart failure is overloaded
• Treating the score as the diagnosis, and missing the patient whose lactate is 4 with a NEWS2 of 4
• Forgetting the wound, drains and lines under the blanket

How this comes up at the CST interview

The CST management and clinical station scores a structured approach, clinical knowledge, prioritisation and escalation, and communication. A sepsis scenario tests all four: the CCrISP order, the NG253 numbers, the decision to call critical care, and a clear handover.

coresurgeryinterview has 299 questions across the portfolio, management and clinical stations with AI-marked spoken practice, and its scenario on the febrile post-operative patient is built on exactly this NG253 structure, so you can rehearse the answer aloud and hear whether the numbers come out in order.