Is Heparin Present in a Deaccessed Port?
No, heparin is not automatically present in a deaccessed port—it depends entirely on what locking solution was used during the last maintenance flush before the port was deaccessed. 1
What Determines Heparin Presence
The presence of heparin in a deaccessed port is determined by institutional protocol and the specific locking solution used at the time of last access:
Current Standard Practice
- Most modern guidelines recommend normal saline as the standard locking solution for implantable ports, meaning many deaccessed ports contain only saline 1
- The American Society for Parenteral and Enteral Nutrition explicitly states that normal saline should be used for routine flushing and locking of port-a-caths, as it has equivalent efficacy to heparin with better safety 1
- The European Society for Clinical Nutrition and Metabolism (ESPEN) gives a Grade B recommendation (95.5% agreement) against routine heparin lock for home parenteral nutrition catheters 1
When Heparin May Be Present
If the port was locked with heparin solution, it would typically contain:
- 100 U/mL heparin concentration as the standard for implantable ports when locked for periods >8 hours 2, 3
- Volume equal to the internal catheter volume (typically 1-3 mL depending on catheter size) 3
Evidence Supporting Saline Over Heparin
The shift away from routine heparin use is supported by robust evidence:
- Multiple meta-analyses demonstrate no benefit of heparin over saline for maintaining port patency 1
- A large adult study of implantable ports found no differences in port malfunction or sepsis between saline versus 100 U/mL heparin flushes 2
- A 2012 retrospective study of 610 implanted ports showed no statistically significant differences in port survival free from occlusive events between heparinized solution and normal saline (P = 0.9 univariate, P = 0.7 multivariate) 4
- A 2022 randomized trial of 143 cancer patients demonstrated that saline locks every 2 months showed no differences in safety, infection, or thrombosis compared to heparin 5
Critical Safety Considerations
Heparin promotes intraluminal biofilm formation, potentially increasing catheter-related bloodstream infection risk 1, 6
This is a major reason why guidelines have moved toward saline-only protocols for routine port maintenance.
Clinical Algorithm for Port Access
When accessing a port of unknown locking solution status:
- Assume saline lock in modern practice (post-2017 guidelines) unless institutional protocol specifically mandates heparin 1
- Always aspirate for blood return first before flushing to confirm patency regardless of locking solution 1
- Flush with saline before any medication administration to clear the lock solution 1
- After completing therapy, flush with saline and lock according to institutional protocol—if the port will remain unused >8 hours and institutional protocol requires heparin, use 100 U/mL concentration 2, 3
Common Pitfall to Avoid
Never assume all ports contain heparin based on older practice patterns—the evidence-based shift to saline-only protocols means many contemporary ports contain no heparin whatsoever 1