A Randomized Controlled Trial of Comparative Efficacy between Sodium Bicarbonate and Heparin as A Locking Solution for Tunneled Central Venous Catheters Among Patients Requiring Maintenance Hemodialysis

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).

Sodium Bicarbonate Locks May Be a Safe and Effective Alternative in Pediatric Intestinal Failure: A Pilot Study

This was a retrospective study that compared outcomes in pediatric intestinal failure (IF) patients that were switched from ethanol lock therapy (ELT) to sodium bicarbonate lock therapy (SBLT). The primary outcome was rate of catheter-related blood stream infections (CRBSI). The secondary outcomes were number of hospitalizations, emergency room (ER) visits, central venous catheter (CVC)-related complications. In 4 patients, median rates of CRBSI were 2.77 (interquartile range [IQR] 0.6-5.6) on ELT versus 0 on SBLT per 1000 catheter days ( P = 0.17). The median rates of hospitalizations and ER visits for CVC-related complications were 6.1 (IQR 3.2-10.2) on ELT versus 0 on SBLT (IQR 0-0; P = 0.11) and 2.8 (IQR 2-3.6) on ELT versus 1.8 (IQR 0-3.7) on SBLT per 1000 catheter days ( P = 0.50), respectively. Rates of CVC-related complications were similar. No adverse events were reported. SBLT may be safe and effective for pediatric IF.

Heparin versus 0.9% sodium chloride locking for prevention of occlusion in central venous catheters in adults

BACKGROUND

Intermittent locking of central venous catheters (CVCs) is undertaken to help maintain their patency and performance. There are systematic variations in care: some practitioners use heparin (at different concentrations), whilst others use 0.9% sodium chloride (normal saline). This review looks at the effectiveness and safety of intermittent locking with heparin compared to normal saline, to see if the evidence establishes whether one is better than the other. This is an update of an earlier Cochrane Review.

OBJECTIVES

To evaluate the benefits and harms of intermittent locking of CVCs with heparin versus normal saline in adults to prevent occlusion.

SEARCH METHODS

We used standard, extensive Cochrane search methods. The latest search date was 20 October 2021.

SELECTION CRITERIA

We included randomised controlled trials in adults ≥ 18 years of age with a CVC that compared intermittent locking with heparin at any concentration versus normal saline. We excluded studies on infants and children from this review.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Our primary outcomes were occlusion of CVCs and duration of catheter patency. Our secondary outcomes were CVC-related bloodstream infections and CVC-related colonisation, mortality, haemorrhage, heparin-induced thrombocytopaenia, CVC-related thrombosis, number of additional CVC insertions, abnormality of coagulation profile and allergic reactions to heparin. We used GRADE to assess the certainty of evidence for each outcome.

MAIN RESULTS

We identified one new RCT with 30 participants for this update. We included a total of 12 RCTs with 2422 participants. Data for meta-analysis were available from all RCTs. We noted differences in methods used by the included studies and variation in heparin concentrations (10 to 5000 IU/mL), time to follow-up (1 to 251.8 days), and the unit of analysis used (participant, catheter, line access). Five studies included ICU (intensive care unit) patients, two studies included oncology patients, and the remaining studies included miscellaneous patients (chronic kidney disease, haemodialysis, home care patients, etc.). Primary outcomes Overall, combined results may show fewer occlusions with heparin compared to normal saline but this is uncertain (risk ratio (RR) 0.70, 95% confidence interval (CI) 0.51 to 0.95; 10 studies; 1672 participants; low-certainty evidence). We pooled studies that used participant or catheter as the unit of analysis. We carried out subgroup analysis by unit of analysis. No clear differences were detected after testing for subgroup differences (P = 0.23). We found no clear evidence of a difference in the duration of catheter patency with heparin compared to normal saline (mean difference (MD) 0.44 days, 95% CI -0.10 to 0.99; 6 studies; 1788 participants; low-certainty evidence). Secondary outcomes We found no clear evidence of a difference in the following outcomes: CVC-related bloodstream infections (RR 0.66, 95% CI 0.08 to 5.80; 3 studies; 1127 participants; very low-certainty evidence); mortality (RR 0.76, 95% CI 0.44 to 1.31; 3 studies; 1100 participants; very low-certainty evidence); haemorrhage (RR 1.54, 95% CI 0.41 to 5.74; 3 studies; 1197 participants; very low-certainty evidence); or heparin-induced thrombocytopaenia (RR 0.21, 95% CI 0.01 to 4.27; 3 studies; 443 participants; very low-certainty evidence). The main reasons for downgrading the certainty of evidence for the primary and secondary outcomes were unclear allocation concealment, suspicion of publication bias, imprecision and inconsistency.

AUTHORS' CONCLUSIONS

Given the low-certainty evidence, we are uncertain whether intermittent locking with heparin results in fewer central venous catheter occlusions than intermittent locking with normal saline in adults. Low-certainty evidence suggests that heparin may have little or no effect on catheter patency duration. Although we found no evidence of differences in safety (CVC-related bloodstream infections, mortality, or haemorrhage), the combined studies were not powered to detect rare adverse events such as heparin-induced thrombocytopaenia. Further research conducted over longer periods would reduce the current uncertainties.