What are the common side effects of hemodialysis via a fistula or subclavian (central venous catheter) and how are they managed in a patient undergoing hemodialysis?

Hemodialysis Vascular Access: Fistula vs Subclavian Catheter

Access Selection Priority

Arteriovenous fistulas should be the primary vascular access for hemodialysis, while subclavian catheters must be avoided in hemodialysis patients due to high risk of subclavian vein stenosis that can preclude future permanent access creation. 1

• The 2019 KDOQI guidelines shifted from "Fistula First" to a patient-centered "P-L-A-N" approach (Patient Life-Plan first, then Access Needs), but fistulas remain preferred due to superior patency and lower infection/thrombosis rates compared to catheters 1
• Less than 10% of chronic maintenance hemodialysis patients should be maintained on catheters as permanent access, defined as catheter use exceeding 3 months without a maturing permanent access 1
• Avoid subclavian site in hemodialysis patients and those with advanced kidney disease to prevent subclavian vein stenosis 1, 2

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Arteriovenous Fistula Complications

Thrombotic Flow-Related Complications

Stenosis from neointimal hyperplasia is the primary cause of fistula dysfunction and thrombosis, requiring surveillance and early intervention. 1

• Target thrombosis rate: After adjusting for initial failures (first 2 months), native AV fistula thrombosis should be less than 0.25 episodes per patient-year 1
• Stenosis increases intra-access pressure and decreases blood flow; if hemodynamically significant and untreated, it progresses to thrombosis 1
• Common stenosis locations: juxta-anastomotic region in fistulas, vein-graft anastomosis in grafts, but can occur anywhere in the access circuit including central veins and feeding arteries 1

Clinical indicators of dysfunction:

• Reduction in dialysis vascular access blood flow rate 1
• Abnormal kinetics during dialysis 1
• Absent pulse and thrill on physical examination indicates thrombosis 1

Management approach:

• Fluoroscopy fistulography or ultrasound duplex Doppler for suspected dysfunction (equivalent alternatives—order only one initially) 1
• Fluoroscopy fistulography with intervention is usually appropriate for treatment once dysfunction confirmed 1
• For suspected thrombosis (absent pulse/thrill): fluoroscopy fistulography guides interventional therapy or surgical consultation 1
• Endovascular interventions are first-line treatment when possible, with over two-thirds occurring outpatient 1

Nonthrombotic Flow-Related Complications

Vascular steal syndrome presents with cardiac failure or ischemic symptoms in the extremity with the access 1

Diagnostic approach:

• Both fluoroscopy fistulography AND ultrasound duplex Doppler are usually appropriate (complementary studies—order both) 1
• May require placement of new tunneled dialysis catheter as bridging therapy while undergoing evaluation 1

Cannulation site aneurysms may threaten access without necessarily affecting flow, but require monitoring for rupture risk 1

Maturation Failure

Failure to mature within 2 months after creation requires imaging evaluation. 1

• Fluoroscopy fistulography or ultrasound duplex Doppler (equivalent alternatives) guide interventional options 1
• Optimal hemodialysis access provides reliable blood flow ≥600 mL/min, is <0.6 cm below skin surface, and has minimal diameter of 0.6 cm (Rule of 6s) 1

Infectious Complications

Infections involving the vascular access (intraluminal or extraluminal) require prompt recognition and treatment. 1

• Fistulas have significantly lower infection rates than catheters 1
• Examine access site for warmth, erythema, purulent drainage, or systemic signs of infection 1

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Subclavian Catheter Complications

Mechanical Complications at Insertion

Immediate mechanical complications occur in approximately 1.7% of subclavian catheter insertions. 3

Specific risks include: 1

• Pneumothorax
• Subclavian artery puncture
• Subclavian vein laceration
• Hemothorax
• Air embolism
• Catheter misplacement

Life-threatening complications: 3

• Left subclavian catheters: Superior vena cava perforation causing right hemothorax or mediastinal hematoma
• Right subclavian catheters: Right atrial perforation causing pericardial tamponade
• Death occurred in 3 of 16 reported cases; emergency surgery required in 5 of 16 cases 3

Prevention strategies:

• Use ultrasound guidance to reduce cannulation attempts and mechanical complications 1, 2
• Apply maximal sterile barrier precautions: cap, mask, sterile gown, sterile gloves, sterile full body drape 1, 4
• Confirm tip position with post-insertion imaging 2

Subclavian Vein Stenosis

Subclavian vein stenosis is the most critical long-term complication, occurring in at least 50% of patients with subclavian catheters. 3

• Stenosis generally precludes use of the entire ipsilateral arm for future vascular access 1
• This is why subclavian site must be avoided in hemodialysis patients and those with advanced kidney disease 1, 2
• PICCs also carry 7% risk of central vein stenosis/occlusion and should not be used in CKD patients 1

Clinical presentation:

• Swelling (soft tissue edema) of extremity ipsilateral to access 1
• Development of venous collaterals 1

Diagnostic approach:

• Fluoroscopy fistulography for suspected central venous stenosis/occlusion 1

Infectious Complications

Catheter-related bloodstream infections occur in approximately 8.9% of patients with subclavian dialysis catheters. 3

Key infectious risks: 1

• Catheter colonization occurs in 10-55% of hemodialysis catheters 1
• S. aureus is the leading cause (33-80% of bloodstream infections) 1
• Deep-seated infections: bacterial endocarditis, septic pulmonary emboli, septic thrombosis 1
• One case of vertebral osteomyelitis reported as sepsis complication 3

Prevention protocol—Hub disinfection:

• Scrub catheter hub with chlorhexidine-based solution or 70% alcohol for at least 15 seconds before connecting to dialysis machine 4
• Repeat scrubbing at disconnection 4
• If chlorhexidine contraindicated, use povidone-iodine solution (preferably with alcohol) 4

Prevention protocol—Exit site care:

• Perform hand hygiene, then examine exit site for infection signs 4
• Disinfect exit site with alcohol-based chlorhexidine (>0.5% solution) for at least 60 seconds 4
• Acceptable alternatives: 10% povidone-iodine for 2-3 minutes or 70% alcohol 4
• Apply povidone-iodine or triple antibiotic ointment after each dialysis session (if compatible with catheter material) 4
• Alternative: chlorhexidine disk (Biopatch) with Tegaderm dressing, changed weekly 4

Prevention protocol—Hand hygiene:

• All staff must perform hand hygiene immediately before and after catheter manipulation 4
• Use alcohol-based hand rubs (superior to soap and water) 4
• Wear gloves and masks while handling catheter during connection/disconnection 4

Prevention protocol—Dressing management:

• Use sterile gauze or sterile transparent semi-permeable dressing 4
• Replace if damp, loosened, or visibly soiled 4
• Monitor site visually when changing dressing or by palpation through intact dressing 4
• Evaluate insertion site daily by palpation through dressing to discern tenderness 1

Management of catheter-related bloodstream infection:

Uncomplicated infection (coagulase-negative staphylococci):

• May retain catheter if no persistent or relapsing bacteremia 1
• Use systemic antibiotic for 7 days plus antibiotic lock therapy 1
• If salvaging catheter: systemic plus antibiotic lock therapy for 14 days 1

Uncomplicated infection (Gram-negative bacilli):

• Remove catheter and treat 10-14 days 1

Complicated infection (tunnel infection, port abscess):

• Remove catheter and treat with antibiotics for 7-10 days 1

Complicated infection (septic thrombosis, endocarditis):

• Remove catheter and antibiotic treatment for 4-6 weeks 1

Complicated infection (osteomyelitis):

• Remove catheter and antibiotic treatment for 6-8 weeks 1

Candida species:

• Remove device and antifungal therapy for 14 days after fungemia clears 1

Thrombotic Complications

Clinical subclavian vein thrombosis occurred in 5 of 148 patients (3.4%) in one series, but systematic investigation reveals at least 50% involvement. 3

• Catheter-related thrombosis ranges from 4-8% symptomatic cases to 27-66% asymptomatic (detected by venography) 2
• Major complications: pulmonary embolism, sepsis 2
• Minor complications: tip clots, lumen obstruction, fibrin sheath formation 2

Risk factors:

• Catheter tip malposition 2
• Prolonged indwelling time 2
• Hypercoagulable states 2

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Connection Procedure for Catheters

Step-by-step protocol: 4

1. Place catheter on nonsterile pad
2. Clamp catheter tubing before removing catheter cap
3. Perform hand hygiene
4. Don gloves and mask
5. Scrub hub with chlorhexidine or 70% alcohol for at least 15 seconds
6. Connect to dialysis machine using aseptic technique

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Critical Pitfalls to Avoid

Site selection errors: 1, 2

• Never use subclavian site in hemodialysis patients or advanced kidney disease patients
• Avoid femoral vein in adult patients (higher infection risk)
• Do not use PICCs in CKD patients (high risk of upper-extremity thrombosis and central stenosis)

Catheter management errors: 1, 4

• Do not routinely replace hemodialysis catheters to prevent infection
• Do not remove catheters based on fever alone without evidence of catheter infection
• Promptly remove any catheter no longer essential
• If placed during emergency without aseptic technique, replace within 48 hours

Access preservation errors: 1

• Avoid venipuncture in potential fistula sites
• Educate patients about vein preservation before dialysis initiation
• Ensure early nephrology referral for timely access planning

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Quality Monitoring

Implement catheter care protocols with regular auditing: 4

• Hand hygiene compliance monitoring
• Vascular access care observation
• Exit site disinfection technique verification
• Hub disinfection practice auditing
• These measures decrease bloodstream infection risk in dialysis patients 4

Access-specific monitoring: 1

• Track thrombosis rates as part of ongoing quality assurance
• Examine underlying causes of access failures
• Maintain center-specific access database to identify problems 1