What is the management for a clotted central line (central venous catheter) during dialysis?

Management of Clotted Central Line During Dialysis

For a clotted hemodialysis catheter, immediately attempt thrombolytic lock therapy with alteplase (2 mg in 2 mL for patients ≥30 kg) instilled into the catheter lumen with a dwell time of 30-120 minutes, and if unsuccessful after two doses, refer for radiological evaluation to assess for catheter malposition, fibrin sheath, or central vein stenosis. 1, 2

Immediate In-Unit Management

First-line treatment should be intraluminal thrombolytic lock therapy administered between dialysis sessions (35-69 hours interdialytic dwell time). 1 The National Kidney Foundation guidelines specify that catheter dysfunction—defined as inability to achieve blood flow of 300 mL/min in a catheter previously delivering >350 mL/min—warrants treatment after 2 consecutive sessions. 1

Thrombolytic Protocol

• Alteplase (Cathflo Activase) is the preferred agent: 2 mg in 2 mL for patients ≥30 kg, or 110% of internal lumen volume (not exceeding 2 mg) for patients <30 kg 2
• Instill into the occluded catheter lumen and assess function at 30 minutes, then again at 120 minutes if needed 2
• A second dose may be administered if function is not restored after the first dose 2
• Success rates are high: 67% restoration after one dose at 120 minutes, and 88% after up to two doses in clinical trials 2
• Tissue plasminogen activator is non-allergenic and can be given repeatedly without side effects 3

Assessment of Catheter Function

Function is restored when you can successfully aspirate 3 mL of blood (or 1 mL in patients <10 kg) and infuse 5 mL of saline (or 3 mL in patients <10 kg) through the catheter. 2 After successful restoration, aspirate 4-5 mL of blood to remove residual clot and thrombolytic agent, then gently irrigate with normal saline. 2

When In-Unit Management Fails

Any dysfunction that cannot be managed in the dialysis unit should be referred for radiographic evaluation. 1 This is critical because the problem may not be simple intraluminal thrombosis.

Radiological Assessment Should Identify:

• Catheter tip malposition (may require repositioning or replacement over guidewire) 1
• External fibrin sheath formation (may require higher-dose lytic infusion or mechanical disruption) 1
• Residual lumen thrombus (may require additional thrombolytic therapy) 1
• Central vein stenosis or occlusion (may require angioplasty, though recurrence is common) 1, 4
• Right atrial thrombus (requires higher-dose systemic thrombolysis) 1

Special Considerations for Hemodialysis Catheters

The duration of thrombosis matters—successful declotting decreases with longer duration of occlusion. 1 This is why patient education is critical: teach all dialysis patients to palpate for thrill/pulse daily at home and report absence immediately. 1

Prevention Strategies

• Antimicrobial lock solutions between dialysis sessions significantly reduce catheter-related bloodstream infections and may reduce thrombotic complications 5
• Proper flushing technique is essential: use heparinized saline locks between treatments 1
• Avoid subclavian vein catheters in hemodialysis patients due to high risk of central vein stenosis that can compromise future ipsilateral access 1, 4

Common Pitfalls to Avoid

Do not attempt to forcefully flush a clotted catheter—this can cause catheter rupture or embolization of thrombus. 1 The evidence shows that gentle thrombolytic instillation with adequate dwell time is far more effective and safer than aggressive mechanical manipulation.

Do not delay radiological referral if two doses of thrombolytic therapy fail—the problem is likely mechanical (malposition, fibrin sheath, or central vein stenosis) rather than simple intraluminal clot. 1

Do not remove the catheter prematurely—even with dysfunction, the catheter may be salvageable with appropriate intervention, and catheter removal in a dialysis patient creates an urgent access crisis. 1 However, if central vein stenosis is refractory and causing symptomatic ipsilateral extremity edema, access ligation may ultimately be necessary. 4

When Systemic Thrombolysis May Be Considered

Systemic thrombolytic therapy is generally NOT recommended for routine catheter thrombosis due to bleeding risk. 1 However, in cancer patients (where much of the evidence originates), systemic thrombolytics may be considered only in specific high-risk circumstances: superior vena cava syndrome with recent, poorly tolerated symptoms, or when catheter maintenance is imperative and local therapy has failed. 1 This same principle would apply to dialysis patients with life-threatening central vein thrombosis, though this is rare.

In patients with severe renal impairment (which includes dialysis patients), if systemic anticoagulation is needed for extensive thrombosis, use unfractionated heparin rather than low molecular weight heparin. 1