Haemodialysis Catheter-Related Bloodstream Infection

Haemodialysis (HD) catheter-related bloodstream infection is a serious and potentially life-threatening complication among patients receiving haemodialysis. It occurs when microorganisms colonize the dialysis catheter and gain access to the bloodstream, leading to local catheter infection, bacteraemia, sepsis, and possible metastatic infections.

Prompt recognition, appropriate microbiological investigation, timely initiation of empirical antibiotics, and effective catheter management are essential to reduce morbidity, mortality, and loss of vascular access. Management should follow established dialysis infection prevention protocols and national dialysis service guidelines.

Epidemiology

Catheter-related bloodstream infection is one of the most common infectious complications associated with haemodialysis vascular access. The risk is significantly higher among patients using temporary or tunneled dialysis catheters compared with those using arteriovenous fistulas or grafts. Infection rates are influenced by catheter duration, catheter care practices, patient immune status, diabetes mellitus, and healthcare-associated exposure.

In Tanzania and other low- and middle-income countries, catheter-related infections remain an important challenge due to increasing numbers of patients requiring dialysis, limited access to permanent vascular access, and resource constraints affecting infection prevention practices.

Risk factors

Common risk factors include:

• Use of haemodialysis catheters.

• Prolonged catheter duration.

• Tunnelled or temporary catheter placement.

• Poor catheter care practices.

• Previous catheter-related infection.

• Diabetes mellitus.

• Immunosuppression.

• Malnutrition.

• Frequent hospitalization.

• Poor hygiene practices.

• Lack of permanent vascular access.

Pathophysiology

Catheter-related bloodstream infection develops when microorganisms colonize the external surface of the catheter, catheter hub, or surrounding skin and subsequently enter the bloodstream.

Bacterial biofilm formation on the catheter surface allows microorganisms to persist despite antibiotic therapy and host immune responses. Infection may remain localized at the catheter exit site or tunnel, or may progress to bloodstream infection causing systemic inflammatory response, sepsis, septic shock, and metastatic infection involving distant organs.

Common causative organisms include:

• Gram-positive organisms, particularly staphylococcal species.

• Gram-negative organisms.

Clinical presentation

Patients may present with:

• Fever (≥37.8°C)

• Chills

• Rigors

• General malaise

• Weakness

• Symptoms of sepsis

Local catheter-related findings may include:

• Exit site redness.

• Exit site tenderness.

• Purulent discharge from catheter exit site.

• Tunnel infection with pain, swelling, or inflammation along the catheter tract.

Clinical signs may include:

• Fever.

• Hypotension in severe infection.

• Tachycardia.

• Features of septic shock.

• Signs of metastatic infection where present.

Diagnostic criteria

Haemodialysis catheter-related bloodstream infection should be suspected in a patient with a dialysis catheter who develops:

• Fever or chills without another identified cause.

• Positive blood cultures.

• Evidence of catheter exit-site or tunnel infection.

Diagnosis is confirmed by microbiological evidence of bloodstream infection together with compatible clinical features.

Investigations

Recommended investigations include:

Microbiological investigations

• Blood cultures before initiation of antibiotics where possible.

Laboratory investigations

• Full blood picture (FBP).

• Serum inflammatory markers where available.

• Kidney function tests.

• Serum electrolytes.

Assessment for complications

Investigate for metastatic infection when clinically indicated, including:

• Echocardiography when infective endocarditis is suspected.

• Imaging of suspected sites of infection.

• Other targeted investigations according to clinical findings.

Management

Management aims to:

• Control infection rapidly.

• Prevent progression to sepsis.

• Preserve vascular access where possible.

• Remove infected catheter when indicated.

• Prevent recurrence.

Non-pharmacological treatment

General measures include:

• Follow principles of sepsis management in patients with shock.

• Obtain blood cultures before antibiotic administration where possible.

• Maintain strict catheter care and infection prevention practices.

• Remove the catheter when indicated, including:

  • Failure to respond to appropriate antimicrobial therapy.

  • Exit-site infection.

  • Tunnel infection.

  • Metastatic infection.

  • Haemodynamic instability.

Pharmacological treatment

The usual duration of antibiotic treatment is 14–21 days, depending on clinical response, organism identified, and presence of complications.

Empirical treatment

Empirical antibiotic therapy should provide coverage against both Gram-positive and Gram-negative organisms while awaiting microbiological results.

Adults

One of the following regimens may be used:

Flucloxacillin 1–6 g intravenously daily in three divided doses

AND

Ceftazidime 1 g intravenously immediately after haemodialysis and 1 g after subsequent haemodialysis sessions

OR

Vancomycin 20 mg/kg intravenously loading dose administered over the last hour of dialysis, followed by 1 g during the last hour of subsequent haemodialysis sessions

AND

Ceftazidime 1 g intravenously immediately after haemodialysis and 1 g after subsequent haemodialysis sessions

Children

Flucloxacillin 25–50 mg/kg/day intravenously in three divided doses

AND

Ceftazidime 50 mg/kg/dose intravenously every 48 hours, administered after dialysis or on dialysis days

OR

Vancomycin 10 mg/kg/dose intravenously (consider monitoring serum vancomycin levels)

AND

Ceftazidime 50 mg/kg/dose intravenously every 48 hours, administered after dialysis or on dialysis days

Tailored antibiotic therapy

Antibiotic therapy should be adjusted according to:

• Blood culture results.

• Antimicrobial susceptibility testing.

• Clinical response.

If cultures remain negative but the patient demonstrates clinical improvement, empirical treatment may be continued according to the clinical situation.

Where recommended antibiotics are unavailable, empirical therapy should cover both Gram-positive and Gram-negative organisms.

Catheter lock therapy

During treatment, catheter lock therapy may be used where appropriate:

• Gentamicin lock.

• Vancomycin lock.

Referral

Refer patients urgently to a nephrologist or higher-level dialysis facility when:

• Septic shock develops.

• There is failure to respond to antimicrobial therapy.

• Catheter removal or replacement is required.

• Metastatic infection is suspected.

• Complex antimicrobial management is needed.

Patients requiring ongoing dialysis should have alternative vascular access planning after resolution of infection.

Complications

Potential complications include:

• Septicaemia.

• Septic shock.

• Endocarditis.

• Metastatic infection.

• Loss of dialysis access.

• Catheter removal.

• Hospitalization.

• Death.

Prognosis

The prognosis depends on early recognition, severity of infection, causative organism, antimicrobial susceptibility, and presence of complications. Prompt initiation of appropriate antibiotics and timely catheter management improve outcomes. Delayed treatment may result in septic shock, organ dysfunction, prolonged hospitalization, and increased mortality.

Prevention

Preventive measures include:

• Strict hand hygiene before catheter handling.

• Proper catheter insertion technique.

• Regular catheter site assessment.

• Use of aseptic technique during dialysis access.

• Appropriate catheter dressing changes.

• Early creation of permanent vascular access where possible.

• Avoidance of unnecessary catheter use.

• Regular staff training on dialysis infection prevention.

• Patient education on catheter care and early reporting of symptoms.