Sodium bicarbonate is a potential alternative to classic heparin as a lock solution for non-tunneled dialysis catheters: a result from the prospective randomized BicarbLock trial.

Objective: Temporary vascular access is mandatory for acute hemodialysis. Heparin lock solution is the standard of care worldwide. Many lock solutions were studied in terms of thrombosis and catheter-related infection prevention, but none replaced heparin as a standard measure. Our main aim is to investigate the effectiveness of sodium bicarbonate (NaHCO3), a ubiquitous and cheap option as a catheter lock solution, in comparison with traditionally used heparin in non-tunneled hemodialysis catheters.
Methods: We conducted our prospective study between March 2021 and March 2022. Our study included 441 patients > 18 years old who needed either femoral or jugular non-tunneled dialysis catheters. Patients were assigned to either heparin (5000 IU/ml) or 8.4% sodium bicarbonate on a consecutive basis. Basic characteristics and information regarding catheters, dialysis sessions, and complications were recorded. We divided patients according to the catheter insertion site as well as the lock solution.
Results: We analyzed 426 patients divided into four groups: jugular heparin (n = 113), jugular bicarbonate (n = 113), femoral heparin (n = 113), and femoral bicarbonate (n = 100). Basal characteristics were similar for all groups. The mean time to last effective dialysis in our institution was 10.7 ± 12.1 days for heparin vs 11.5 ± 10.8 days for the bicarbonate group. 25 (5.9%) patients had some kind of blood flow problems (13 in the heparin and 12 in the bicarbonate group). There was no significant difference in terms of catheter malfunction among groups (p = 0.50). Out of these 25 cases, only 12 (7 in heparin and 5 in the bicarbonate arm) had catheter dysfunction (p = 0.386). Sixty-four patients (28%) with jugular catheters were discharged with patent catheters and continued their dialysis in other facilities.
Conclusion: Sodium bicarbonate is as effective as classic unfractionated heparin in preventing catheter lumen thrombosis with a comparable incidence of catheter-related complications. Furthermore, it is a cost-effective option that can be used confidently, especially when heparin is contraindicated.
Trial Registration: ClinicalTrials.gov Identifier: NCT04772209 (26.02.2021).
(© 2023. The Author(s), under exclusive licence to Springer Nature B.V.)