Maintenance of Intravenous Line Patency

Introduction to Intravenous Line Patency

• For maintaining intravenous line patency, use heparin flush 10 units/mL, 1-3 mL every 8-24 hours when the catheter is not in use, or after each use for intermittent access, as recommended by the American College of Clinical Nutrition (Grade A) 1
• The American College of Clinical Nutrition recommends using normal saline (0.9% sodium chloride) flush only for standard peripheral IV lines and frequently used central lines (Grade A) 1

Standard Peripheral IV Lines and Central Lines

• For standard peripheral IV lines and frequently used central lines, use normal saline flush only, with a volume of 5-10 mL before and after medication administration (Grade A) 1
• No heparin is needed for catheters in frequent use 1

Open-Ended Central Venous Catheters

• For open-ended central venous catheters, when not in use for more than 8 hours, use heparin concentration of 10-100 units/mL, volume of 3-5 mL, and frequency of every 8-24 hours when not in use 1

Implanted Ports

• For implanted ports, use heparin concentration of 100 units/mL, volume of 5 mL, and frequency of every 4 weeks when not in use, as per manufacturer recommendations 1

Flushing Techniques

• Always flush with normal saline first, before heparin administration, after blood draws or medication administration, using 5-10 mL normal saline 1
• Mandatory saline flush between lipid solutions and heparin is recommended when used with lipid-containing parenteral nutrition (Grade B) 1
• Saline flushing is mandatory during parenteral nutrition with lipids before any flushing with heparin (Grade B), as recommended by the ESPEN guidelines 1
• A saline flush should always be interposed between lipid-containing PN admixtures and heparin, according to the ESPEN guidelines 1

Manufacturer-Specific Guidance

• Follow manufacturer instructions for implanted ports and specialized catheters 1
• Close-ended valve catheters should be flushed with saline only 1

Meta-Analyses and Concentration of Heparin

• Meta-analyses suggest intermittent flushing with heparin may be no more beneficial than flushing with normal saline alone for many catheter types 1
• The concentration of heparin (50-500 units/mL) is less important than proper saline flushing technique before heparinization 1
• For catheter locking, a concentration between 50 and 500 units per mL of heparin in normal saline solution is suggested (Grade C), as recommended by the ESPEN guidelines 1

Flushing Frequency

• For small caliber devices (≤5 Fr), weekly flushing is typically sufficient; for larger caliber devices (≥6 Fr), flushing every 3-4 weeks is recommended 1

Occlusion Management

• If occlusion occurs, consider thrombolytic agents (urokinase 5000 U/mL) for established occlusions 2
• Never forcefully flush an occluded catheter 2
• Normal saline flushing is not inferior to heparin flushing regarding catheter occlusion and has a lower risk of biofilm formation in the catheter lumen, as reported in Clinical Nutrition 3
• The 2023 ESPEN practical guideline for home parenteral nutrition recommends using sodium chloride 0.9% instead of heparin to lock long-term CVAD (Grade B) 3
• Potential complications of heparin use include bleeding, thrombocytopenia, allergic reactions, and osteoporosis, as reported in Clinical Nutrition 2
• In premature newborns, there may be an increased risk of intraventricular hemorrhage associated with heparin use, as reported in Clinical Nutrition 2