Access Complications and Infection

Access Complications and Infection

Quick Answer: AV fistulas are preferred long-term access because infection and hospitalization rates are lowest. Catheters carry the highest bacteremia risk. Purulent access drainage means do not cannulate—notify the physician. Steal syndrome, stenosis, and thrombosis each have distinct assessment findings and referral triggers.

Vascular access complications account for a large share of hemodialysis morbidity and are heavily weighted on the CDN exam. You must differentiate infection, stenosis, thrombosis, aneurysm, steal syndrome, and central venous stenosis—and know which findings allow dialysis to proceed versus which require immediate escalation.

Access Types and Baseline Risk

KDOQI "Fistula First" prioritizes native AVF creation and maturation (often 6–8 weeks for radiocephalic fistulas) before cannulation. Cannulation requires mature vessel diameter and flow—often confirmed with ultrasound or surgical evaluation.

Infection: Local vs Systemic

Local access infection may present with erythema, warmth, tenderness, or purulent drainage at cannulation sites or graft tunnels. Systemic access-related bacteremia presents with fever, chills, rigors, and hypotension—often within 30–60 minutes of starting dialysis when bacteremia is released from biofilm.

Priority actions for suspected bacteremia during dialysis:

1. Draw blood cultures (peripheral and from access if protocol allows).
2. Stop dialysis and disconnect circuit safely.
3. Notify physician; prepare for IV antibiotics.
4. Do not resume using the infected access until cleared.

The most common source of bacteremia in hemodialysis patients is the vascular catheter—infection rates are roughly 10–20 times higher than with AVF. Exam questions often pair fever/chills shortly after dialysis start with catheter access.

Pre-dialysis finding: purulent drainage at AVF site. Correct action: do not cannulate; notify physician for culture, antibiotics, and possible access salvage plan. Cleaning with alcohol and proceeding is unsafe.

Non-Infectious Complications

Steal syndrome (access-related ischemia): hand pain, numbness, cool fingers, weak pulse distally—especially during dialysis when flow through the access increases. Weak thrill plus hand pain during treatment should raise suspicion. Management is surgical evaluation; do not ignore symptoms as "normal."

Stenosis / outflow obstruction: rising venous pressures, prolonged bleeding after needle removal, arm swelling, decreased thrill, poor clearance. Recirculation should stay ≤10%; higher values suggest needle placement or stenosis. Ultrasound fistulogram and angioplasty may be needed.

Thrombosis / impending clot: sudden loss of thrill and bruit, swelling, pain. The access may be clotted and unusable—notify vascular access team urgently.

Aneurysm / pseudoaneurysm: focal outpouching at repeated cannulation sites; monitor for rupture risk and rotate cannulation sites (ladder or area technique per policy).

Central venous stenosis: ipsilateral arm, breast, and face swelling; prominent chest wall veins—often history of prior catheter. Requires imaging and possible angioplasty/stent.

Cannulation Technique Essentials

• Arterial and venous needles oriented with bevel up; arterial needle typically directed toward arterial inflow, venous toward heart—follow unit protocol and ROPE mapping.
• Initial cannulation of mature fistula often uses 17-gauge needles; technique must minimize vessel trauma.
• Buttonhole technique uses the same tract repeatedly; infection risk rises if asepsis fails—strict disinfection required.
• Maximum recirculation for well-functioning access: ≤10%.

Worked Scenario: Fever at Dialysis Start

A patient with a tunneled internal jugular catheter develops fever 38.9°C, rigors, and hypotension 30 minutes into treatment. No local drainage is visible.

Analysis: Time course suggests catheter-related bacteremia with endotoxin release during dialysis initiation—not pyrogenic dialyzer reaction (more common in first hour with back pain, often without rigors) and not simple UF-related hypotension without fever.

Priority: cultures, stop dialysis, antibiotics per order, plan catheter removal/replacement after cultures when clinically appropriate.

Surveillance Checklist (Each Treatment)

1. Inspect access skin and catheter exit site before cannulation.
2. Palpate thrill; auscultate bruit when trained.
3. Monitor venous pressures and arm swelling intradialytically.
4. Assess hemostasis time post-needles.
5. Teach patient daily thrill check between sessions.

CDN Exam Traps

• Trap: Cannulate alternate arm when access has purulent drainage. Correct: Do not use infected access; notify physician.
• Trap: AVF has lowest infection risk so fever is never access-related. Correct: AVF infections occur but catheters remain the leading bacteremia source.
• Trap: Weak thrill always means clot. Correct: Also consider steal, hypotension, or needle malposition—correlate with exam and timing.

Prolonged Bleeding and Hemostasis

Prolonged bleeding after needle removal may indicate outflow stenosis, excess anticoagulation, or uremic platelet dysfunction. Apply direct pressure, elevate the arm, and notify the physician if hemostasis exceeds protocol limits. Do not resume cannulation at the same site if a hematoma is expanding.

Referral Triggers Summary

Access surveillance is continuous nursing work: pre-treatment inspection, intradialytic monitoring of pressures and symptoms, and post-treatment hemostasis assessment protect patients and preserve lifelines.