01Principles and purposeThe professional or clinical skill and the decisions it supports.
Preventing a surgical site infection involves reducing microbial inoculation and maintaining the conditions in which the patient can resist infection and heal. Antibiotics, skin preparation, sterile practice, tissue handling and physiological care contribute at different points. A prophylactic dose cannot compensate for gross contamination, an unrecognised collection or poorly perfused tissue. Equally, careful skin preparation does not remove the need for an indicated antibiotic. The preoperative plan should make each relevant intervention explicit and avoid treating one completed task as evidence that the whole prevention strategy is adequate.
Wound classification helps explain the indication. Clean surgery does not enter a normally colonised hollow tract and has no encountered inflammation; placement of an implant increases the consequence of infection. Clean-contaminated surgery enters a relevant tract under controlled conditions. Contaminated surgery involves greater contamination or a major break in technique. Dirty or infected surgery already involves infection or comparable contamination requiring therapeutic management. The classification can change during an operation, so the postoperative antibiotic decision may differ from the preoperative plan.
National guidance establishes principles, while the local formulary selects regimens for particular operations and microbial risks. Local recommendations reflect likely organisms, resistance patterns, allergy alternatives and practical preparation. They should not be represented as a single national gold standard for every operation. Product information establishes licensed dosing and administration precautions, but does not replace operation-specific stewardship. Record whether an antibiotic is prophylactic or therapeutic, when it was administered and when it should stop or be reviewed. Ambiguous continuation is a common route from one useful dose to an unnecessary prolonged course.
Key points
- Antibiotic prophylaxis targets contamination at surgery; established infection needs its own treatment and source-control plan.
- NICE recommends prophylaxis for clean implant surgery, clean-contaminated surgery and contaminated surgery.
- Clean uncomplicated surgery without a prosthesis does not routinely require antibiotic prophylaxis.
- Choose the agent through the local operation-specific formulary, checking allergy, likely organisms and patient factors.
- Give prophylaxis at an effective time before contamination, considering infusion duration and any tourniquet.
- Allow alcohol-based skin preparations to dry and prevent pooling before draping or diathermy.
02Situations and prioritiesThe context, relevant information and actions that matter most.
A recorded antibiotic allergy needs clarification of the drug, reaction, timing and severity. Nausea and an immediate systemic hypersensitivity reaction do not imply the same risk. Do not remove a label casually or ignore a convincing severe reaction to meet the operating schedule; select an appropriate alternative with pharmacy or microbiology support.
Pus, perforation with infection or a suspected infected collection changes the task from prevention alone to treatment and source control. Assess physiology and obtain the appropriate surgical and antimicrobial plan. A single prophylactic dose is not a complete response to established intra-abdominal infection.
A prescription marked as given may have been administered long before a delayed operation or after incision. Check the actual time, agent and dose and discuss whether repeat administration is indicated. Repeating blindly can also cause harm if the first administration is merely poorly documented.
Visible pooling, wet drapes or incompletely dried preparation creates a hazard when an ignition source is used. Pause and correct the preparation safely according to the product and theatre protocol. Starting diathermy because the surgeon is ready does not make the solvent non-flammable.
03Assessment and interpretationHow to gather information, assess the situation and recognise uncertainty.
Consider the information, its meaning and its limitations before deciding what follows.
- 01
Identify the procedure-specific indication - Why
- Determine whether prevention is needed and which organisms must be covered.
- Interpretation and limitations
- Check the operation, wound class, implant and patient risks against the local formulary. A regimen suitable for skin flora may not cover organisms expected when bowel is opened. The need for anaerobic coverage should be an explicit part of the choice where relevant.
- 02
Reconcile allergies and recent antibiotics - Why
- Avoid serious hypersensitivity, unnecessary duplication and gaps in spectrum.
- Interpretation and limitations
- Review reaction details, cultures or colonisation information where relevant, and antibiotics already being administered. Existing therapeutic treatment does not automatically ensure appropriate prophylactic timing or coverage, but it may make an extra unrelated dose unnecessary.
- 03
Check dose, timing and repeat criteria - Why
- Ensure effective drug exposure when operative contamination can occur.
- Interpretation and limitations
- Account for the agent’s infusion time, half-life, operation duration and local redosing rules, with renal or body-size adjustments where indicated. A tourniquet can limit delivery to the operative field, so prophylaxis must be coordinated before inflation.
- 04
Select and apply the skin preparation safely - Why
- Match antisepsis to the anatomical site and product restrictions.
- Interpretation and limitations
- Check allergies, proximity to mucosa and the intended use of diathermy. Alcohol-based chlorhexidine is an option favoured by NICE when suitable, but alternatives are needed for contraindications or specific sites. Drying and prevention of pooling are part of correct application, not optional finishing steps.
04Worked approachesCases with ordered reasoning, an action and a check of the outcome.
01Worked caseVerify administration before redosingA 70-kg adult with normal renal function and no beta-lactam allergy is having a short clean orthopaedic implant procedure without a tourniquet. For this example, the approved local policy specifies cefuroxime 1.5 g IV at induction, with repeat dosing considered for prolonged surgery or major blood loss and no routine postoperative course. The prescription was entered at 07:00; incision is planned at 09:15, but the team initially cannot establish when the dose was given.+
- 1Pause and reconcile the administration record with the giving clinician. They confirm cefuroxime 1.5 g IV was administered from 09:00 to 09:03 at induction; 07:00 was the prescription time, not delivery. Record the verified timing and check allergy and cumulative exposure.
- 2Calculate that the planned incision is 12 minutes after completion. The operating team expects 45 minutes of surgery, finishing about 10:00, or 60 minutes after the dose began. The selected cefuroxime product describes a roughly 70-minute serum half-life with normal renal function; combine that with the supplied local policy rather than treating prescription age as drug exposure.
- 3The responsible clinician decides not to give a duplicate dose before incision: a full indicated dose has just been verified. Proceed with the agreed skin-preparation and drying checks. This clean procedure has no expected bowel contamination; do not generalise the selected regimen to bowel surgery needing anaerobic coverage.
- 4Track actual duration and blood loss. Unexpected prolongation or major loss triggers reassessment and policy-directed repeat dosing; NICE advises giving a repeat dose when an operation lasts longer than the half-life of the antibiotic given. The no-redose decision at 09:15 does not settle every later intraoperative decision.
- 5At sign-out verify wound classification, any unexpected infection, all actual doses and the agreed stop instruction. If the planned short clean course was unchanged, stop prophylaxis without routine postoperative doses under the supplied policy; a new treatment indication needs its own documented prescription.
02Established infectionA prophylaxis order in a septic surgical patientAn adult who is not pregnant or recently pregnant has a suspected perforated viscus with physiological deterioration and is booked for urgent surgery.+
- 1Assess and resuscitate promptly with senior surgical and anaesthetic input, using the applicable sepsis pathway. Identify the likely source and the need for operative source control; a normal temperature alone cannot exclude sepsis.
- 2Prescribe therapeutic antimicrobial treatment appropriate to the suspected source and local guidance, obtaining suitable cultures without delaying time-critical treatment. Coordinate any peri-incision prophylaxis requirement with the treatment already given.
- 3After source control, review cultures, clinical response and the operative findings to refine spectrum and duration. Do not use a generic prophylaxis label to justify either undertreating infection or continuing broad-spectrum treatment without review.
03Skin preparationPreventing a fire and protecting sensitive anatomyAn alcohol-based preparation has collected beneath the patient before abdominal surgery using diathermy.+
- 1Alert the team and prevent draping or ignition while the preparation remains pooled or wet. Remove soaked material and allow appropriate drying using the product and theatre safety process.
- 2Check that the preparation is suitable for the operative site and has not contacted a vulnerable area contrary to its instructions. Additional applications do not necessarily improve antisepsis and may increase exposure or delay drying.
- 3Confirm readiness again before proceeding and report the process issue if relevant. Prevention depends on noticing the physical state of the preparation, not solely recording which antiseptic was selected.
05Relevant medicines and safetySpecific regimens and precautions when the skill involves prescribing.
Cefuroxime: example component of surgical prophylaxis
For an adult where the local formulary selects cefuroxime for an appropriate gastrointestinal, gynaecological or orthopaedic procedure: 1.5 g intravenously at induction, administered over 3–5 minutes according to this SmPC. NICE supports considering a single prophylactic dose; any intraoperative repeat follows duration, pharmacokinetics and local policy. This product also licenses optional 750 mg intramuscular doses at 8 and 16 hours for these procedures, but they should not be added routinely without a procedure-specific indication.This is an example, not a universal bowel-surgery regimen. Avoid in cefuroxime or cephalosporin hypersensitivity and previous immediate or severe reactions to other beta-lactams as specified by the product. Review renal impairment, concurrent nephrotoxic medicines and C. difficile risk. Check whether existing antibiotic treatment supplies suitable spectrum and timing. Do not extrapolate this formulation for intracameral use.
06Feedback, follow-up and evidenceReview outcomes, seek feedback and identify what to improve.
- Record actual antibiotic administration and redosing times, the indication and any observed reaction. Precise timing allows later teams to assess exposure without reconstructing it from memory.
- Check that continuation orders distinguish prophylaxis from treatment and include a stop or review point. A drain remaining in place does not by itself establish a need for prolonged systemic antibiotics.
- Observe the wound and patient for evolving infection, recognising that deep or organ-space infection may have limited superficial changes. Escalate new pain, systemic deterioration, discharge or dehiscence according to the clinical picture.
- Give wound-care and contact advice before discharge and explain antibiotics actually received. Patients need to know which changes require review and who can assess them after they leave the surgical ward.
07Special situationsVariants, exceptions and circumstances that change the usual approach.
Hair removal can introduce injury
Do not remove hair solely as a routine infection-prevention ritual. If removal is required for the procedure, use an appropriate electric clipper with a single-use head on the day rather than a razor that can create skin microtrauma.
Decolonisation is locally selected
Nasal and skin decolonisation may be considered for procedures in which staphylococcal infection is an important risk. Selection should consider the operation, patient and consequences of infection. It is not automatically required for every person entering theatre.
Long operations require reassessment
An adequate initial dose can become insufficient during a prolonged procedure. The repeat decision depends on the specific drug and relevant pharmacokinetics, with the local policy providing operational detail. Write who will prompt the review instead of relying on someone remembering elapsed time.
Allergy clarification improves both safety and stewardship
A careful reaction history can prevent both accidental re-exposure and unnecessary use of broader alternatives. Formal reassessment or delabelling follows an appropriate pathway; the pressure of an operating list is not a setting for an improvised drug challenge.
08Common pitfallsFrequent interpretation and management errors.
- 01
Assuming every clean operation needs antibiotics while overlooking an implant or controlled bowel entry that changes the indication.
- 02
Using one prophylactic dose as the entire treatment for a dirty or infected operative field.
- 03
Copying a local antibiotic combination into teaching as a nationally preferred regimen for all patients and procedures.
- 04
Starting diathermy over wet alcohol-based preparation or leaving soaked material beneath the patient.