What should I do if I can flush a Peripherally Inserted Central Catheter (PICC) line but there's no blood backflow?

Management of PICC Line with Absent Blood Return but Intact Flush Ability

If you can flush a PICC line but cannot obtain blood return, the catheter may still be functional and should not be immediately removed—first assess for partial occlusion, fibrin sheath formation, or catheter malposition, then attempt pharmacological clearance with thrombolytic agents if clinically indicated. 1

Understanding the Problem

Absent blood return with intact flush ability is a common PICC complication that does not necessarily indicate complete catheter failure. This scenario typically suggests:

• Partial intraluminal obstruction from fibrin sheath formation, blood clots, or precipitate buildup 1
• Catheter tip malposition or migration from the optimal cavoatrial junction position 2
• One-way valve effect from fibrin sheath allowing fluid out but preventing blood aspiration 1

Immediate Assessment Steps

Clinical Evaluation

• Check for signs of infection or thrombosis: Look for arm pain, swelling, redness at the insertion site, or systemic symptoms (fever, chills) 2
• Assess catheter external integrity: Examine for kinking, damage, or dislodgement of the external portion 1
• Verify proper flushing technique: Use a 10 mL or larger syringe to avoid excessive pressure that could damage the catheter 1

Functional Testing

• Attempt gentle aspiration using proper technique with a 10 mL syringe 2
• Flush with 10 mL normal saline using turbulent push-pause technique to confirm patency 2
• Document the ease of flushing: Resistance during flushing suggests more significant occlusion 2

Management Algorithm

If Catheter Flushes Easily Without Resistance

1. Continue using the PICC for infusions if clinically necessary, as the catheter remains functional for medication delivery 1
2. Avoid using the line for blood draws until blood return is restored 1
3. Consider radiographic verification of tip position if the problem persists, as malposition increases complication risk 2

If Attempting to Restore Blood Return

Pharmacological clearance is the appropriate first-line intervention for PICCs and long-term venous access devices rather than immediate removal or exchange. 1

Thrombolytic Therapy Protocol

• Use recombinant tissue plasminogen activator (alteplase/Cathflo Activase) or urokinase as first-line agents 1, 3
• Dosing for alteplase:
  • Patients ≥30 kg: 2 mg in 2 mL instilled into the catheter 3
  • Patients <30 kg: 110% of internal lumen volume, not exceeding 2 mg in 2 mL 3
• Dwell time: Assess catheter function after 30 minutes; if unsuccessful, reassess at 120 minutes 3
• Second dose: If function not restored after 120 minutes, a second equal dose may be instilled 3
• Always use ≥10 mL syringe to avoid excessive pressure during instillation 1

Alternative Clearance Solutions (Based on Suspected Cause)

• Ethanol for lipid aggregate obstruction 1
• NaOH or HCl for drug precipitates 1
• NaHCO₃ for contrast medium 1

When to Consider Catheter Exchange or Removal

Exchange Over Guidewire is Appropriate When:

• Pharmacological clearance fails and the PICC remains clinically necessary 1
• Changes to catheter characteristics are needed (e.g., number of lumens, power-injection compatibility) 1
• No signs of local or systemic infection are present 1

Immediate Removal is Indicated When:

• Signs of catheter-related bloodstream infection with positive blood cultures 1
• Symptomatic venous thrombosis persisting despite 72+ hours of therapeutic anticoagulation 1
• The PICC is no longer clinically necessary 1
• Catheter damage or rupture is identified 1

Maintenance to Prevent Future Occlusion

• Flush with normal saline (not heparin) after each use for catheters in frequent use 1
• For intermittently accessed PICCs: Flush weekly with 5-10 U/mL heparinized saline 1
• Use proper flushing technique: 10 mL or larger syringe with turbulent push-pause method 2
• Avoid blood product infusions through the PICC when possible to reduce clot formation 1

Critical Pitfalls to Avoid

• Never use syringes smaller than 10 mL for flushing or clearance attempts, as excessive pressure can rupture the catheter 1
• Do not advance a migrated PICC regardless of how far it has dislodged; guidewire exchange is the appropriate intervention 1
• Avoid immediate removal of a functional PICC solely due to absent blood return if the catheter remains clinically necessary 1
• Do not ignore persistent symptoms: If arm swelling, pain, or systemic symptoms develop, evaluate for thrombosis or infection immediately 2