1. Treat as urgent if dialysis cannot be delivered

• Both lumens completely non-aspirable/non-flushable
• Missed dialysis with breathlessness, pulmonary edema, severe hypertension, confusion, weakness, or ECG changes
• Suspected hyperkalemia: weakness, palpitations, bradycardia, syncope
• Fever, chills/rigors during dialysis, exit-site pus, tunnel pain/redness, or unexplained hypotension
• Neck/face/arm swelling on the catheter side, suggesting central venous obstruction
• Catheter is damaged, leaking, displaced, or the cuff is exposed

2. First bedside assessment by trained dialysis staff

A. Define the dysfunction

• Can blood be aspirated?
• Can it be flushed easily?
• Is there low blood flow during MHD, frequent arterial pressure alarms, venous pressure alarms, or recirculation?
• Is one lumen affected or both?

B. Look for simple mechanical or positional causes

1. Inspect external tubing and clamps.
   • Ensure clamps are open.
   • Check for tightly applied sutures/dressing, line compression, cracks, or visible kinking.
2. Confirm correct connection and that caps/connectors are not obstructed.
3. Reposition the patient.
   • Supine, then slight Trendelenburg if tolerated.
   • Turn head, ask patient to cough or take a deep breath.
   • Change arm/shoulder position.
   • In femoral catheters, straighten the hip and avoid thigh flexion.
4. Attempt gentle aspiration and normal-saline flush using sterile technique.
5. Reverse arterial and venous lines only as a temporary dialysis workaround, with close monitoring of adequacy and recirculation. It does not solve the cause.

3. If thrombotic occlusion is likely: thrombolytic lock

Typical approach

• Alteplase (tPA), commonly 1-2 mg per lumen, made up only to the catheter’s exact internal fill volume, or
• Urokinase where that is the locally available protocol.

Safety points

• First assess bleeding risk: active bleeding, very recent surgery/procedure, severe thrombocytopenia, recent intracranial bleeding, etc.
• Do not overfill beyond the labelled lumen volume because drug can enter the systemic circulation.
• Do not push the clot into the circulation by force.
• If function returns, deliver dialysis and lock the catheter correctly after treatment.
• Recurrent need for thrombolytic locks should trigger imaging and a plan for catheter intervention, not repeated indefinite rescue locks.

4. If thrombolytic treatment fails or blockage repeatedly recurs

Investigations

• Chest X-ray or fluoroscopy to check tip position, migration, pinch/kink, and catheter integrity.
• Catheter contrast study/venography to identify:
  • Fibrin sheath
  • Tip thrombus
  • Catheter malposition
  • Central venous stenosis or occlusion
• Doppler/venous imaging if arm, neck, breast, or facial swelling suggests venous thrombosis/stenosis.
• Blood cultures if infection is suspected.

Definitive procedural options

1. Guidewire catheter exchange
   • Replace the dysfunctional tunneled catheter while preserving the venous route where appropriate.
2. Fibrin sheath disruption/plasty
   • Balloon disruption of the fibrin sheath, often at catheter exchange.
   • Fibrin sheath is very common in malfunctioning catheters and may cause one-way-valve behavior: easy flush but poor aspiration.
3. Catheter repositioning or replacement at a new site
   • Needed for catheter migration, damage, persistent malposition, or unsuitable existing tract.
4. Central venoplasty/stenting in selected central venous stenosis
   • Performed when clinically significant stenosis is demonstrated, particularly with ipsilateral swelling or access dysfunction.
5. Temporary non-tunneled dialysis catheter
   • Used if urgent dialysis is required and the PermCath cannot be salvaged immediately, especially in severe hyperkalemia, pulmonary edema, or uremic emergency.

5. Always rule out catheter-related infection

• Fever or rigors, especially during/after dialysis
• Hypotension or sepsis
• Exit-site discharge, erythema, crusting, or tenderness
• Tunnel tenderness, induration, or redness
• Positive blood cultures

6. Prevent repeated PermCath blockage

• Use meticulous aseptic connection/disconnection and dressing care.
• Ensure correct lock solution and exact lumen fill volume after every dialysis session.
• Use the dialysis unit’s approved heparin or citrate lock protocol. A review notes that 4% citrate or heparin-based locks are commonly used for maintaining catheter patency. Catheter lock evidence review
• Avoid withdrawing blood or giving medicines through the PermCath unless specifically required and done by trained staff.
• Minimize line manipulation and prevent clamp damage.
• Evaluate recurrent dysfunction early rather than repeatedly using rescue locks.
• Plan permanent vascular access, preferably an AV fistula or graft when feasible, because a tunneled catheter carries continuing risks of thrombosis, bacteremia, and central venous stenosis.

Practical algorithm