Objective: Multiple in vitro and in vivo studies indicate that there is a significant amount of dialysis catheter lock leak with tunneled and nontunneled dual lumen hemodialysis (HD) catheters. The impact of heparin 1000 unit/mL HD catheter lock on outcomes in patients on therapeutic heparin has not been previously reported.

Methods: Twenty-nine patients with 42 patient events on HD or continuous renal replacement therapy (CRRT) via double lumen catheters were retrospectively analyzed. Study patients received heparin 1000 unit/mL HD catheter lock while on therapeutic intravenous heparin. All patients had stable activated partial thromboplastin times (PTT) prior to catheter locking and had a PTT drawn within 6 h after administration of the heparin HD catheter lock.

Results: The average prelock PTT was 56 s and postlock PTTs increased on average to 85 s (p < 0.0001). PTTs were significantly higher when drawn closer to the administration time of the heparin catheter lock. Major bleeding occurred in many surgical patients after heparin HD catheter lock administration.

Conclusion: Citrate or saline HD catheter lock may be preferable to heparin HD catheter lock in patients on intravenous heparin infusions, especially in high-bleed-risk surgical patients.

Tuggle TS, Noureddine L, Hobbs RA. Impact of Heparin Hemodialysis Catheter Lock on Partial Thromboplastin Time Assays in Inpatients on Therapeutic Intravenous Heparin. Semin Dial. 2025 Jun 5. doi: 10.1111/sdi.13260. Epub ahead of print. PMID: 40473907.