Intra-Arterial Heparin Flushing Guidelines

Primary Recommendation: Use Normal Saline

The American College of Cardiology recommends using sterile 0.9% sodium chloride (normal saline) as the standard flush solution for arterial catheters, with continuous infusion at 3 mL/hour providing equivalent patency compared to heparinized solutions, based on high-quality evidence from multiple meta-analyses 1
Multiple meta-analyses demonstrate that intermittent flushing with heparin provides no additional benefit over normal saline alone for maintaining arterial line patency, with a moderate strength of evidence 1

For arterial catheters accessed intermittently, flushing with 5-10 U/mL heparinized saline 1-2 times weekly can be considered, though evidence supporting this is extrapolated from adult venous catheter studies, with a low strength of evidence 2, 1
When heparin is deemed necessary, use concentrations between 1-10 U/mL for arterial lines, significantly lower than the 50-500 U/mL range used for central venous catheters, based on expert opinion from the American Society of Health-System Pharmacists 1

Heparin promotes intraluminal biofilm formation, potentially increasing catheter-related bloodstream infection risk, with a high strength of evidence from the Centers for Disease Control and Prevention 1

Maintain strict aseptic technique during any manipulation of the arterial catheter system to reduce infection risk, based on high-quality evidence from the World Health Organization 1
Use 10 mL or larger syringes for flushing to prevent excessive pressure that could damage the catheter, with a moderate strength of evidence from the American Society for Healthcare Engineering 1
Employ turbulent push-pause technique when flushing to create turbulence that helps clear the catheter lumen, based on expert opinion from the Society of Critical Care Medicine 1
If occlusion occurs, attempt forceful irrigation with saline first; if this fails, use fibrinolytic drugs (urokinase or alteplase) for thrombotic occlusions, with a high strength of evidence from the American College of Chest Physicians 1

Avoid using heparin immediately before or after lipid-containing infusions through the same catheter, as heparin may facilitate lipid precipitation, based on expert opinion from the American Society of Health-System Pharmacists 1
Do not use heparin concentrations higher than 10 U/mL for arterial line flushing, as this provides no additional benefit and increases risk, with a moderate strength of evidence from the American College of Cardiology 1
Never use syringes smaller than 10 mL for flushing, as excessive pressure can damage the catheter integrity, based on high-quality evidence from the Association for the Advancement of Medical Instrumentation 1