Dialysis-access infection

01OverviewDefinition, clinical context and the essential points that orientate the chapter.

Repeated cannulation breaches the skin barrier, and haematoma, buttonhole tracts, ulceration or poor skin integrity can seed a native fistula. Prosthetic AV grafts add a surface on which organisms adhere and form biofilm, reducing antimicrobial penetration and host clearance. Infection may remain localised as erythema or drainage, extend to an abscess or infected pseudoaneurysm, or enter the bloodstream. Staphylococci are common, but Gram-negative organisms and polymicrobial infection occur, so appearance alone cannot select definitive therapy.

Management separates native from prosthetic access and superficial from deep disease. Stable superficial inflammation requires careful examination, cultures when discharge is present and close follow-up. Bacteraemia, deep collection, graft exposure, infected aneurysm, anastomotic involvement, thrombosis or bleeding demands urgent multidisciplinary care. ESVS includes dialysis access bridge graft infection within peripheral graft infection and recommends antimicrobial therapy for every infected graft, combined with debridement and removal of infected material where possible. The access life-plan matters, but preserving a circuit cannot take priority over controlling sepsis or preventing rupture.

Key points

In sepsis, obtain at least two sets of peripheral blood cultures if this does not delay treatment, start renal-adjusted intravenous antibiotics promptly, and resuscitate while arranging dialysis-safe ongoing care.
Purulence, sinus formation, deep collection or exposed prosthetic graft requires urgent vascular source-control planning; retained infected material carries persistent infection, disruption and bleeding risk.
Sentinel or active bleeding from an infected access is a surgical emergency: apply direct control, activate major-haemorrhage support and do not blindly clamp or probe the anastomosis.
Avoid needling through cellulitis, ulceration, purulence or exposed material; identify an uncontaminated alternative route for essential dialysis.
Collect multiple direct deep tissue, perigraft fluid or explanted graft samples when feasible; superficial swabs often identify colonisers rather than the biofilm pathogen.
Narrow antibiotics to culture and susceptibility results with infection and renal specialists, accounting for dialysis clearance, residual kidney function and the presence of prosthetic material.
A localised fistula needle-site infection may sometimes be treated while preserving access, but bacteraemia, abscess, infected aneurysm or anastomotic involvement demands escalation.
Treatment duration starts from adequate source control and bloodstream clearance, not merely the first antibiotic dose; retained or replaced prosthetic material usually lengthens therapy.

02AetiologyUnderlying causes, associations and risk factors, with why each one matters.

Cannulation inoculation

Repeated skin breach, buttonhole tracts, poor asepsis and cannulation through damaged skin permit organisms to enter native or prosthetic access.

Prosthetic biofilm

Bacteria adhere to graft material and form protected communities that resist host clearance and antimicrobial penetration, promoting relapse when material remains.

Haematogenous seeding

Bacteraemia from another site can seed prosthetic material, while infected access can disseminate to heart valves, spine, joints and distant organs.

03PathophysiologyThe causal sequence from the underlying abnormality to symptoms and harm.

1
Local tissue invasion
Cellulitis may extend into an abscess, graft tunnel, aneurysm or anastomosis, causing necrosis, thrombosis and loss of structural integrity.
2
Bloodstream dissemination
Organisms entering access flow produce bacteraemia and sepsis and may seed endocardium, bone, joints or other vascular structures.
3
Anastomotic destruction
Deep infection weakens arterial and venous walls, causing pseudoaneurysm, sentinel bleeding and sudden rupture with catastrophic haemorrhage.

04Clinical features and red flagsSymptoms, examination findings, patterns of presentation and time-critical warnings.

Local needle-site infection

Focal erythema, warmth, tenderness or discharge at a recent puncture may be superficial, but depth, fluctuance, access function and systemic symptoms must be checked.

Deep fistula infection

Abscess, infected thrombus, persistent bacteraemia, aneurysm tenderness, skin breakdown or purulent drainage suggests extension beyond uncomplicated cellulitis.

Prosthetic graft infection

Sinus, exposed graft, perigraft collection, recurrent bacteraemia, pseudoaneurysm or graft disincorporation strongly suggests biofilm infection requiring source-control assessment.

Bacteraemic sepsisRed flag

Rigors during or after dialysis, fever, hypotension, confusion, tachypnoea or rising lactate can occur even when local access signs are subtle.

Impending ruptureRed flag

Sentinel bleeding, rapidly thinning or necrotic skin, pulsatile mass, infected pseudoaneurysm or visible anastomosis requires immediate haemorrhage control and vascular surgery.

Red flags requiring action

Hypotension, confusion, rigors, rising lactate or rapidly progressive erythema indicates systemic infection requiring immediate resuscitation, cultures and intravenous antibiotics.
Sentinel bleeding, an exposed anastomosis, pseudoaneurysm, skin necrosis or a pulsatile infected mass risks sudden exsanguination and requires emergency vascular control.
Persistent Staphylococcus aureus bacteraemia, a new murmur, embolic signs, back pain or focal joint pain raises concern for endocarditis or metastatic infection.
Purulence, fluctuance, deep tenderness or graft exposure indicates deep infection in which antibiotics alone rarely eradicate prosthetic biofilm.
A painful inflamed access with absent thrill may be infected and thrombosed; do not proceed to routine declotting until infection has been assessed.

05InvestigationsWhat to request, why it matters and how to interpret it.

Investigation order

Read from the initial assessment onwards. Tests may run in parallel in urgent care; first-line, preferred, confirmatory, definitive and gold-standard labels appear only when the chapter explicitly states them.

01
Blood cultures before antibioticsFirst step
Why
Obtain at least two peripheral sets in systemic illness, ideally before therapy when this causes no harmful delay, and repeat to document clearance in significant bacteraemia.
Interpretation and limitations
Concordant growth supports bloodstream infection; persistent S. aureus or other virulent bacteraemia suggests uncontrolled source, endocarditis or metastatic seeding.
02
Direct deep sampling — preferred microbiologyPreferred
Why
Send multiple tissue, perigraft-fluid or explanted-material specimens during drainage or surgery, before antibiotics where safe, rather than relying on surface swabs.
Interpretation and limitations
Direct samples better represent the biofilm pathogen. Superficial or sinus swabs can contain colonising flora and should not override stronger deep or blood-culture evidence.
03
Duplex ultrasound
Why
Assess access patency, thrombus, pseudoaneurysm, depth and extent of a collection and guide aspiration when appropriate.
Interpretation and limitations
A collection, disincorporation, infected thrombus or pseudoaneurysm strengthens the need for source control; a negative scan does not exclude early or biofilm infection.
04
Cross-sectional or advanced imaging
Why
Use CT angiography to define deeper graft involvement, gas, fluid, anastomotic disruption or operative anatomy; consider specialist nuclear imaging when uncertainty persists.
Interpretation and limitations
Imaging supports extent and procedural planning but must not delay surgery for active bleeding, threatened rupture or rapidly progressive sepsis.
05
Metastatic infection assessment
Why
Use echocardiography and symptom-directed spine, joint or other imaging for persistent S. aureus bacteraemia, embolic signs, new murmur or focal pain.
Interpretation and limitations
Endocarditis, discitis, septic arthritis or embolic infection changes source control, antibiotic selection and duration.

06Differential diagnosisRealistic alternatives and the features that help distinguish them.

Sterile infiltration haematoma

Bruising after difficult needling may be tender without progressive erythema, purulence or systemic illness; infection can secondarily complicate it.

Thrombophlebitis or thrombosis

A painful firm access with lost thrill may be sterile thrombosis, but fever or inflammatory skin change requires cultures before routine declotting.

Contact dermatitis

Dressing or antiseptic reactions are pruritic and patterned to exposure, lacking deep tenderness, purulence, bacteraemia or a perigraft collection.

Post-operative inflammation

Early bruising and mild wound inflammation may resolve, whereas expanding erythema, discharge, fever or increasing pain suggests infection.

07ManagementImmediate care, first-line treatment, alternatives and escalation.

01Emergency pathwaySepsis or threatened access ruptureFirst stepUse for shock, altered mental state, rapidly progressive infection, purulence over an anastomosis, exposed graft, pseudoaneurysm or sentinel bleeding.

1Resuscitate, control external bleeding with direct pressure, obtain blood cultures if this causes no delay, begin renal-adjusted broad intravenous cover and involve vascular surgery, renal and infection teams immediately.
2AlternativeDo not cannulate or declot the infected segment; create a parallel plan for essential dialysis through the safest alternative site while preserving future veins where possible.
3Drain abscess, debride devitalised tissue and remove infected prosthetic material urgently when indicated; active anastomotic bleeding or rupture requires immediate operative control.
4Send multiple direct specimens, narrow therapy when results return, repeat blood cultures to clearance and investigate endocarditis or metastatic infection when the organism and clinical course warrant.

02Stable pathwayLocalised infection without systemic featuresUse for focal erythema or discharge with stable observations, preserved thrill and no abscess, graft exposure, bleeding or bacteraemia.

1Mark and photograph the involved area, assess depth and access function, culture purulent discharge and obtain blood cultures if fever, rigors or systemic symptoms are present.
2Avoid cannulation through affected skin, start appropriate renal-adjusted therapy after sampling and arrange early expert review because apparently local disease can track along prosthetic material.
3EscalationReview within 24–48 hours or sooner for progression; escalate to imaging and source control for persistent pain, fluctuance, bacteraemia, thrombosis, exposure or failure to improve.

03Definitive pathwayConfirmed deep graft infectionDefinitiveUse when direct sampling, imaging or operative findings show prosthetic involvement, sinus, collection or infected pseudoaneurysm.

1Define involvement of graft body and anastomosis, perfusion after removal and the need for immediate reconstruction using an access-lifecycle multidisciplinary decision.
2Remove infected material and debride thoroughly where feasible, reconstruct only when needed for limb or dialysis strategy, and cover viable structures with healthy tissue when appropriate.
3Continue culture-directed therapy: ESVS indicates at least 2 weeks intravenous then 2–4 weeks oral after complete removal and debridement, while replacement graft usually needs 4–6 weeks intensive therapy and retained material may require prolonged suppression.

Key medicines and prescribing safety2 treatments · regimens, roles and cautions

Narrow-spectrum definitive therapy when cultures confirm susceptible methicillin-sensitive staphylococci and the infection specialist judges an antistaphylococcal penicillin appropriate.

Flucloxacillin intravenous — susceptible MSSA

1 g IV every 8–12 hours in severe renal failure with creatinine clearance under 10 mL/min; the product is not significantly removed by haemodialysis, so no supplemental dialysis dose is required. Duration follows bloodstream clearance and source control: complete graft removal may allow 2 weeks IV then 2–4 weeks oral therapy; endocarditis, metastatic infection, replacement or retained material requires a longer specialist course.

Contraindicated with any history of hypersensitivity to penicillins or other beta-lactam agents, and with previous flucloxacillin-associated jaundice or hepatic dysfunction. Monitor liver and kidney function during prolonged treatment, sodium load, neutropenia and high-dose hypokalaemia. Severe renal impairment, sepsis, malnutrition and concomitant paracetamol increase high-anion-gap metabolic acidosis risk. In pregnancy use when benefit outweighs risk; limited human data have not established teratogenicity.

Empiric or definitive Gram-positive cover when MRSA is plausible or a serious immediate beta-lactam allergy precludes flucloxacillin; combine with locally selected Gram-negative cover when severe sepsis or local epidemiology requires it.

Vancomycin intravenous — MRSA or serious beta-lactam allergy cover

For adults receiving intermittent haemodialysis, give 15 mg/kg IV as the RRT starting dose and redose according to a pre-dialysis serum level, dialysis membrane and residual kidney function; a critically ill patient may need an unreduced 25–30 mg/kg loading dose. Infuse each dose over at least 60 minutes or at no faster than 10 mg/min, whichever gives the longer administration time. Continue only until cultures permit narrowing, then set total duration by source control, bacteraemia clearance and metastatic infection.

There is no safe fixed dialysis interval: high-flux haemodialysis increases clearance, so obtain levels before dialysis and usually replace after the session according to the result. Monitor ototoxicity, infusion reactions, blood counts and concurrent nephrotoxic or ototoxic drugs. In pregnancy use only if clearly needed and monitor levels carefully; increased doses may be required.

08ComplicationsImportant consequences, why they occur and why they matter clinically.

Septic shock

Access bacteraemia can progress rapidly to cardiovascular collapse and multi-organ dysfunction, with dialysis dependence complicating fluid and drug management.

Metastatic infection

S. aureus and other virulent pathogens can cause endocarditis, vertebral infection, septic arthritis, emboli or distant abscesses.

Haemorrhage

Infected aneurysm or anastomotic disruption may present with a sentinel bleed before life-threatening rupture and exsanguination.

Access and vein loss

Excision may be necessary for cure, leading to temporary catheter dependence and narrowing future access choices.

09Monitoring and follow-upTreatment response, safety checks and longer-term review.

Repeat observations, lactate and organ-perfusion assessment during sepsis, adjusting fluid and vasopressor treatment to dialysis dependence, cardiac reserve and pulmonary oedema risk.
Inspect and palpate the whole access daily for spread, fluctuance, sinus, skin thinning, bleeding, thrombosis and thrill, and document which segments must not be cannulated.
Repeat blood cultures until clearance in significant bacteraemia, especially S. aureus, and track organism, susceptibility and source-control date when setting treatment duration.
Monitor full blood count, CRP trend, liver function, electrolytes and residual kidney function, plus medicine-specific vancomycin levels or flucloxacillin toxicity during prolonged therapy.
After graft excision or salvage, review wound healing, recurrent drainage, access function, dialysis adequacy and the succession-access plan, with longer surveillance if prosthetic material remains.

10Special situationsVariants, exceptions and circumstances that change the usual approach.

Biofilm changes cure

Antibiotics may suppress planktonic bacteraemia while organisms persist on prosthetic material. Deep graft infection therefore often fails without removal and debridement.

Duration starts at control

Count the clinical course from adequate source control and bloodstream clearance. Prosthetic replacement, incomplete excision, endocarditis or metastatic seeding prevents a short fixed course.

Dialysis changes exposure

Drug clearance varies by membrane, session and residual function. Vancomycin therefore needs level-based redosing, while flucloxacillin is not significantly removed by dialysis.

Bleeding can be infective

A small sentinel bleed over an infected pseudoaneurysm or exposed anastomosis may precede catastrophic rupture and demands emergency vascular action.

Pregnancy needs joint prescribing

Severe infection still requires prompt treatment. Maternal sepsis risk, altered vancomycin exposure, fetal monitoring and dialysis prescription should be managed jointly with obstetric, renal and infection teams.

11Common pitfallsFrequent interpretation and management errors.

01
Treating a draining graft sinus with repeated oral antibiotics alone leaves infected prosthetic biofilm and risks recurrent sepsis or anastomotic disruption.
02
Waiting for culture results in septic shock delays life-saving therapy; take cultures promptly, then start empiric antibiotics and narrow later.
03
Letting a superficial swab override deep tissue or blood cultures can target colonisers and miss the true graft pathogen.
04
Using standard renal-function dosing in a haemodialysis patient without checking dialysis clearance creates underexposure or toxicity.
05
Cannulating through inflamed, ulcerated or exposed access tissue risks inoculation, haemorrhage and false reassurance from temporary dialysis flow.

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