Heparin locks with low and high concentration in haemodialysis patients: A systematic review and meta-analysis.

AIM There is no evidence-based consensus on the optimal concentration for heparin locks; several randomized controlled trials (RCTs) have evaluated the concentration of heparin locks, yet the results remain inconsistent. We aimed to assess heparin locks with low and high concentration in haemodialysis patients. METHODS We performed a systematic review and meta-analysis of RCTs focusing on the concentration in heparin locks. Studies were identified by searching PUBMED, EMBASE, Science Direct, Cochrane Central Register of Controlled Trials, China National Knowledge Infrastructure (CNKI) and Wanfang databases (from inception to 15 March 2020). Summary risk ratios or mean differences with 95% confidence interval were calculated. RESULTS A total of 370 patients with four RCTs were included. Heparin locks with 1000 U/ml could significantly reduce the activated partial thromboplastin time (APTT) compared with 5000 U/ml. No significant differences were seen in the occurrence of catheter-related thrombosis, the length of catheter stay, the rates of bleeding and catheter occlusions between the two groups. CONCLUSIONS Lower concentrations in heparin lock are optimal for shortening APTT in haemodialysis patients; further studies are needed to elucidate the role of heparin concentration in the lock practice.