Heparin Lock vs Saline Lock for IV Access

Introduction to Lock Solution Selection

The European Society for Clinical Nutrition and Metabolism (ESPEN) explicitly recommends against routine heparin lock with Grade B recommendation and 95.5% agreement, stating saline should be the standard 4

For central venous catheters accessed daily or frequently, routine heparin cannot be recommended over saline due to lack of proven benefit 1, 2, 3
For intermittently accessed central venous catheters, flushing with 5-10 U/mL heparinized saline 1-2 times weekly helps maintain patency 1, 2, 3, 4
For implanted ports closed >8 hours, heparinized solutions should be used as a lock after proper saline flushing 4
For open-ended catheter lumens remaining closed >8 hours, heparin lock is recommended 4
For manufacturer-specific recommendations, follow device-specific instructions 4

When using saline locks, flush with volume at least twice the catheter volume 5
When using saline locks, use ≥10 mL syringes to prevent excessive pressure that could damage the catheter 5, 6
When using saline locks, employ turbulent push-pause technique to create turbulence that clears the catheter lumen 5, 6
When heparin is indicated, use 5-10 U/mL concentration for intermittent flushing 1, 2, 3, 4

Heparin promotes intraluminal biofilm formation, potentially increasing catheter-related bloodstream infection risk 4, 5
Never use heparin immediately before or after lipid-containing parenteral nutrition, as heparin facilitates lipid precipitation 4, 5
Potential systemic effects of heparin include thrombocytopenia and bone disease, which outweigh thrombosis risk in most cases 5

For newborns with PICCs, heparin has shown effectiveness in preventing occlusion, but potential risks have not been defined, so routine use cannot be recommended 1, 2, 3
For children receiving home parenteral nutrition, insufficient evidence exists to advocate prophylactic anticoagulants for reducing catheter-related thrombosis, occlusion, and infection 1, 2, 3