Dialysis complications and access emergencies

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

Dialysis access complications threaten both life and future kidney-replacement therapy. Fistulae and grafts can bleed, thrombose, stenose, become infected, develop aneurysms, reduce distal perfusion or impose a high cardiac flow burden. Central venous catheters add bloodstream infection, tunnel infection, thrombosis, malposition, fibrin sheath and air-entry risks. The first action is dictated by immediate physiology—control haemorrhage, support ABCDE and treat sepsis—while preserving the access whenever that remains safe.

Extracorporeal treatment introduces a separate set of hazards. A displaced venous needle can pump a large blood volume outside the body without a reliable machine alarm. Kinked tubing, access recirculation and clotting reduce delivered dialysis. Contaminated dialysate, excessive temperature, mechanical red-cell damage, air entry or membrane hypersensitivity are uncommon but can affect more than one patient, so an event may require unit-level quarantine and reporting as well as individual care.

Peritoneal access problems range from exit-site infection and flow failure to leaks, hernia and peritonitis. Cloudiness is the key patient-visible alarm. Across modalities, clinicians outside the renal unit should resist improvised access manipulation: stabilise, document the access findings and engage dialysis, interventional radiology, vascular surgery, microbiology or critical care through the local pathway.

Key points

Major haemorrhage from a fistula, graft, needle or disconnected circuit is immediately life-threatening: summon emergency help, stop the pump when relevant and apply firm direct pressure to the exact bleeding point.
A previously functioning fistula with an absent or abruptly changed thrill may be thrombosed; protect the limb and contact the renal access team urgently because salvage becomes more difficult with delay.
Fever, rigors or hypotension in a person with a dialysis catheter is catheter-related bloodstream infection until assessed, but chest, urine, skin, fistula and peritoneal sources must also be sought.
Cold fingers, paraesthesia, hand weakness, rest pain or tissue loss distal to an access suggests steal syndrome; neurological deficit or threatened tissue requires urgent vascular review.
Marked arm, neck or facial swelling on the access side suggests venous outflow obstruction or central venous stenosis rather than simple fluid overload.
Aneurysmal access with shiny thinning skin, ulceration, scab, infection or rapid expansion has rupture potential and needs urgent specialist assessment; never cannulate through compromised skin.
During haemodialysis, acute dyspnoea, chest or back pain, collapse or abnormal circuit blood may indicate air embolism, haemolysis, dialyser reaction, blood loss or acute coronary disease; secure the circuit and use ABCDE.
Cloudy peritoneal dialysate warrants immediate PD-team contact, effluent sampling and prompt protocol treatment even without fever; fungal or refractory episodes may require catheter removal.
Do not use a fistula or dialysis catheter for routine ward access, blood sampling or infusion without the renal team's authorisation and trained aseptic technique.

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

Access bleeding or occlusion

Needle displacement, circuit disconnection, aneurysmal skin breakdown, fistula or graft thrombosis and central venous obstruction can abruptly threaten circulation, access viability or the limb.

Dialysis-associated infection

Tunnelled catheters, cannulation sites and peritoneal catheters provide routes for bloodstream, access, exit-site or peritoneal infection in physiologically vulnerable patients.

Treatment and circuit events

Rapid ultrafiltration, dialyser reactions, air entry, haemolysis, anticoagulation and blood loss can produce sudden hypotension, dyspnoea, pain or collapse during haemodialysis.

Peritoneal access failure

Peritoneal access problems include flow failure, leaks and hernias; pain or cloudy effluent must also prompt urgent assessment for peritonitis.

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

1
Rapid circulatory loss
High-flow vascular access or an open extracorporeal circuit can lose blood quickly, reducing venous return and tissue perfusion before a haemoglobin change is measurable.
2
Access flow interruption
Thrombus, stenosis or steal alters the low-resistance access circuit, causing loss of dialysis flow, venous hypertension or inadequate distal arterial perfusion.
3
Acute intravascular events
Bloodstream infection, dialyser reaction and haemolysis can each cause acute cardiopulmonary instability during dialysis and require distinct immediate safety actions.
4
Peritoneal infection
Catheter-related infection can inflame the peritoneum, causing cloudy effluent and requiring immediate peritoneal-dialysis-team sampling and protocol treatment.

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

Access haemorrhage

Pulsatile or persistent bleeding, a blood-soaked dressing, falling pressure or circuit disconnection can represent rapid external blood loss.

Thrombosed fistula

The normal continuous thrill and bruit disappear or become markedly altered, often after preceding low flow, stenosis, hypotension or difficult cannulation.

Access infection

Erythema, warmth, purulence, tenderness, pseudoaneurysm change, fever or rigors may involve a fistula, graft, catheter exit site, tunnel or bloodstream.

Distal ischaemia

A cool pale hand, delayed capillary refill, sensory change, weakness, rest pain or ulceration downstream from access suggests dialysis-associated steal.

Venous hypertension

Unilateral access-arm oedema, collateral veins, prolonged bleeding and sometimes face or breast swelling point to outflow stenosis.

High-flow burden

A large pulsatile access with worsening heart failure, wide pulse pressure or pulmonary hypertension may be contributing excessive cardiac shunt flow.

Dialysis disequilibrium

Headache, nausea, agitation, confusion or seizure during early aggressive dialysis can reflect cerebral oedema after rapid osmotic change, once other emergencies are excluded.

Red flags requiring action

Uncontrolled access bleeding with shock requires emergency medical services, focused compression and resuscitation; do not release pressure repeatedly to inspect the wound.
Sudden absent fistula flow is a same-day renal access emergency, particularly when potassium or fluid control depends on imminent haemodialysis.
Fever with rigors, hypotension, altered consciousness or a dialysis catheter requires the sepsis pathway and urgent source-control discussion.
Severe hand rest pain, motor deficit or digital ulceration indicates threatened limb tissue and needs urgent vascular assessment.
Dark red or port-wine circuit blood with chest pain, dyspnoea or hyperkalaemia suggests haemolysis; stop treatment and do not retransfuse circuit contents.
Acute respiratory or neurological symptoms after suspected air entry require immediate circuit clamping and emergency resuscitation support.
Abdominal rigidity, shock or faeculent or fungal PD culture raises surgical or complex peritonitis and catheter-source-control concerns beyond routine outpatient therapy.

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
Focused access examinationFirst step
Why
Distinguish bleeding, loss of flow, infection, aneurysm, outflow obstruction and distal ischaemia.
Interpretation and limitations
Inspect the whole access and skin, palpate thrill, auscultate bruit, compare limb perfusion and avoid compressing an already low-flow fistula.
02
Duplex ultrasound
Why
Assess access patency, stenosis, thrombus, pseudoaneurysm, flow and selected steal physiology.
Interpretation and limitations
The access team interprets anatomical and flow findings with clinical urgency; imaging must not delay haemorrhage control or septic source management.
03
Blood cultures
Why
Identify access-related bacteraemia and guide antimicrobial narrowing and catheter decisions.
Interpretation and limitations
Collect the locally specified peripheral and catheter or circuit sets before antibiotics when safe, including time and source labels; prior therapy reduces yield.
04
Full blood count, clotting and group sample
Why
Quantify anaemia and coagulopathy and prepare for transfusion during significant access bleeding.
Interpretation and limitations
Early haemoglobin can underestimate acute loss, so resuscitation follows physiology and ongoing haemorrhage rather than waiting for a low number.
05
ECG, renal profile and blood gas
Why
Detect potassium disturbance, acidosis, hypoglycaemia, haemolysis consequences and shock during an acute event.
Interpretation and limitations
Sampling timing relative to dialysis changes interpretation; plasma-free haemoglobin, LDH and haptoglobin may support haemolysis after immediate safety actions.
06
Circuit and machine review
Why
Identify needle displacement, line separation, pressure change, air, temperature, conductivity or membrane events.
Interpretation and limitations
Preserve logs, consumables and samples according to governance procedure; similar symptoms in several patients increase concern for a shared technical cause.
07
PD effluent studies
Why
Confirm peritonitis and define bacterial, fungal or polymicrobial infection.
Interpretation and limitations
Send cell count with differential and correctly inoculated culture before empirical intraperitoneal antibiotics whenever delay is avoidable.

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

Acute coronary syndrome or pulmonary embolism

Chest pain, dyspnoea or collapse during dialysis may be unrelated to the circuit; ECG, biomarkers and appropriate imaging proceed alongside immediate dialysis safety measures.

Non-access sepsis

Pneumonia, urinary, skin and abdominal infection can cause rigors or hypotension; cultures and examination should not anchor solely on a dialysis catheter.

Generalised fluid overload

Bilateral oedema and pulmonary congestion favour systemic volume excess, whereas marked unilateral access-side arm, neck or facial swelling suggests venous outflow obstruction.

Complex abdominal infection

Abdominal rigidity, shock or faeculent effluent suggests complex or surgical peritonitis rather than routine outpatient disease and requires urgent specialist assessment.

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

01BLEEDMajor access haemorrhageFirst stepA fistula, graft, needle site or dialysis circuit is bleeding heavily or the patient is haemodynamically unstable.

1Call emergency help, lie the patient safely, expose only what is needed and apply continuous firm direct pressure with a gloved hand and gauze to the precise bleeding point.
2If dialysis is running, trained staff stop the blood pump and clamp affected lines while maintaining pressure and preventing further air entry or blood loss.
3Follow major-haemorrhage ABCDE care with large-bore access away from the fistula limb, blood sampling and transfusion activation according to physiology.
4Obtain urgent renal and vascular surgical control; use any tourniquet or haemostatic adjunct only within emergency-service or local protocol because access and limb can be sacrificed.

02NOFLOWAbsent fistula thrillA patient or clinician can no longer feel the usual access vibration or dialysis flow fails abruptly.

1Re-examine gently for bruit, pulse, swelling, pain and distal perfusion, and establish when normal flow was last definitely present.
2Avoid cannulation, venepuncture, pressure cuffs, tight dressings and repeated compression on the affected limb while contacting the access service urgently.
3Check current potassium, volume and next dialysis requirement so the renal team can plan both thrombectomy or radiological salvage and temporary clearance if needed.
4Arrange duplex, fistulography or intervention through the access pathway; do not give unsupervised systemic thrombolysis or anticoagulation as a substitute for mechanical assessment.

03SEPSISSuspected access infectionFever, rigors, purulence, tunnel pain, inflamed access or unexplained hypotension occurs in a dialysis patient.

1AlternativeApply the sepsis assessment, inspect every access component and look for alternative sources without delaying antimicrobials in an unstable patient.
2Take source-labelled blood cultures and relevant wound or effluent samples according to renal and microbiology guidance.
3Give renal-adjusted empirical cover for likely organisms under the local pathway, accounting for dialysis timing, allergies and previous resistant isolates.
4Coordinate source control: graft infection, tunnel infection, persistent bacteraemia or particular organisms may require catheter removal or surgical treatment rather than repeated antibiotics alone.

04CIRCUITAcute extracorporeal eventCollapse, acute dyspnoea, chest or back pain, neurological change or abnormal circuit blood develops during haemodialysis.

1Stop the relevant machine process, clamp lines as trained and call resuscitation and senior dialysis staff while beginning ABCDE assessment.
2Look immediately for external blood loss, air, haemolysis, dialyser reaction, arrhythmia, acute coronary syndrome, sepsis and hypoglycaemia.
3Do not return circuit blood when haemolysis, contamination or incompatible dialysate is suspected; preserve equipment and machine records for investigation.
4EscalationTreat the defined emergency, assess whether other patients are exposed and complete renal-unit incident escalation and device reporting.

Key medicines and prescribing safety4 treatments · regimens, roles and cautions

Cover likely Gram-positive and Gram-negative bloodstream pathogens while microbiology and source-control decisions are pending.

Empirical therapy for catheter-related infection

Administer the local dialysis-adjusted intravenous regimen after cultures, timed around haemodialysis and modified for allergy and prior isolates.

Doses and levels differ profoundly in dialysis; antibiotic lock is not enough for sepsis, and persistent bacteraemia or high-risk organisms may mandate catheter removal.

Restore flow when fibrin or thrombus within a haemodialysis catheter is the likely mechanical cause.

Thrombolytic catheter lock

Instil only the product-specific lumen volume and dwell prescribed by trained renal staff for suspected intraluminal catheter occlusion.

Never inject a lock systemically or use it for a thrombosed fistula; exclude clamps, kinks, malposition and bleeding risk and follow aspiration instructions exactly.

Partially or fully reverse unfractionated heparin when clinically significant ongoing anticoagulant effect contributes to life-threatening bleeding.

Protamine after heparin-related bleeding

Use only a calculated emergency dose based on heparin type, amount and elapsed time with renal, haematology or anaesthetic input.

Hypotension, anaphylactoid reaction and pulmonary vasoconstriction can occur; it does not replace direct haemorrhage control, and low-molecular-weight heparin reversal is incomplete.

Protect the myocardium while potassium shifting and definitive dialysis access or alternative removal are urgently arranged.

Intravenous calcium for hyperkalaemic toxicity

Follow the UKKA setting-specific adult calcium regimen when severe hyperkalaemia produces ECG toxicity during access failure.

Calcium does not remove potassium; monitor ECG and give insulin-glucose surveillance and other treatment under the hyperkalaemia algorithm.

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

Haemorrhagic shock

Uncontrolled fistula, graft or circuit bleeding can cause rapid exsanguination, cardiovascular collapse and secondary cerebral or myocardial ischaemia.

Permanent access loss

Delayed treatment of thrombosis, infected aneurysm or central stenosis can prevent salvage, forcing temporary catheter use and reducing future vascular options.

Sepsis and metastatic infection

Access-related bacteraemia may progress to shock, endocarditis or other deep infection, while muted inflammatory signs can delay recognition.

Limb or neurological injury

Severe steal, embolic events or air entry can cause tissue ischaemia, weakness, altered consciousness or permanent loss of function.

Peritoneal catheter loss

Fungal or refractory peritonitis may require catheter removal, interrupting peritoneal dialysis and requiring a revised kidney-replacement plan.

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

Teach patients to check the fistula thrill daily and to report change, prolonged bleeding, skin breakdown, swelling, cold fingers or rest pain without waiting for the next session.
Before cannulation, document access skin, thrill, bruit, aneurysmal segments and distal perfusion; trend machine pressures and achieved flow during treatment.
After a bleeding event, monitor haemodynamics, repeated haemoglobin where useful, coagulation, wound stability and distal circulation while maintaining specialist follow-up.
For access bacteraemia, track cultures to clearance, fever, inflammatory response and metastatic infection signs, and document the catheter retention or removal decision.
Reassess the hand and neurological function after any intervention for steal, thrombosis or compression, not merely the technical access flow.
Record repeated intradialytic events by machine, dialyser lot and shift so a shared water, equipment or consumable problem can be detected early.
After PD infection, confirm effluent clearing, organism-specific response, technique review and whether recurrent disease meets catheter-removal criteria.

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

The thrill is surveillance

A patient's daily comparison may detect access thrombosis earlier than a scheduled clinic examination.

Tiny wound, major blood flow

A small defect over a high-flow fistula can cause catastrophic haemorrhage, especially through thin aneurysmal skin.

Pressure must be focused

Firm compression at the source controls bleeding while indiscriminate circumferential force risks thrombosing the entire access.

Catheter fever needs source control

Antibiotics can temporarily suppress bacteraemia while an infected tunnel or biofilm continues to seed the circulation.

An access affects the heart

Very high shunt flow can worsen heart failure even when the fistula itself delivers excellent dialysis.

Clusters reveal machine hazards

Similar acute symptoms across stations should trigger immediate unit-level technical and water-quality investigation.

11Common pitfallsFrequent interpretation and management errors.

01
Do not remove a blood-soaked dressing repeatedly; reinforce focused pressure while urgent help and definitive control are arranged.
02
Do not delay referral for an absent thrill until the next routine dialysis appointment.
03
Do not place a cannula, pressure cuff or constrictive dressing on a threatened fistula arm.
04
Do not treat catheter-related bacteraemia with antibiotic lock alone when there is systemic infection.
05
Do not cannulate through ulcerated, infected or markedly thinned aneurysmal access skin.
06
Do not return circuit blood when mechanical haemolysis, chemical contamination or excessive dialysate temperature is possible.
07
Do not label a cold painful hand as ordinary neuropathy before assessing access-related ischaemia.