Low-dose versus high-dose heparin locks for hemodialysis catheters: a systematic review and meta-analysis

Background: Low-dose heparin lock has been suggested as an effective and safe catheter lock in hemodialysis. However, whether a low-dose lock is superior to a high-dose heparin lock in preventing catheter-related infections and maintaining catheter patency is inconclusive. Study design: A systematic review and meta-analysis was performed by searching in NGC (National Guideline Clearinghouse), Cochrane Library, Joanna Briggs Institute Library, MEDLINE, EMbase, RNAO (Registered Nurses' Association of Ontario), Nursing Consult, PubMed, OVID, China Biology Medicine disc (CBMdisc), China National Knowledge Infrastructure (CNKI), Chongqing VIP (CQVIP), Wanfang Data Knowledge Service Platform, and major nephrology journals. Setting and population: Patients receiving hemodialysis with central venous catheters. Selection criteria for studies: Randomized controlled trials (RCT), controlled clinical trials (CCT), and cohort studies comparing low-dose heparin lock with high-dose heparin lock in hemodialysis patients with central venous catheters. Intervention (exposure): Locking central venous catheters with low-dose heparin lock. Outcomes: Primary outcomes include bleeding-related complications and catheter-related infections. Secondary outcomes include catheter retention time, catheter thrombosis/occlusion incidence, and catheter dysfunction. Results: Five RCTs and three CCTs were eventually identified for the meta-analysis, with 916 patients in total. Meta-analysis showed that, compared with the high-dose heparin group (>= 5,000 U/mL), the low-dose (< 5,000 U/mL) heparin lock could significantly reduce the incidences of bleeding-related complications RR = 3.29, 95% CI (2.19, 4.94), p < 0.00001) and catheterrelated infections (RR = 1.66, 95% CI (1.01, 2.73), p = 0.04). However, no significant differences were observed in the catheter retention time MD = 9.32, 95% CI (-6.70, 25.35), p = 0.25), catheter thrombosis/occlusion incidence (RR = 0.68, 95% CI (0.28, 1.65), p = 0.39), or catheter dysfunction (RR = 1.07, 95% CI (0.75, 1.53), p = 0.71) between the high-and low-dose heparin groups. Conclusion: Low-dose heparin lock could decrease the incidences of catheter-related infections and bleeding-related complications without influencing the catheter retention time or the incidence of catheter thrombosis/occlusion or catheter dysfunction. Low-dose heparin lock solution should be recommended for the hemodialysis patients using central venous catheter in clinic.