Efficacy of antimicrobial lock solutions in preventing catheter-related blood stream infection in haemodialysis patients: a systematic review and meta-analysis of prospective randomised controlled trials

Background: Catheter-related blood stream infection (CRBSI) contributes to morbidity and mortality among patients on haemodialysis (HD). We carried out a systematic review and meta-analysis to assess the efficacy of antimicrobial lock solutions (ALS) in preventing CRBSI. Method: Electronic search of randomised controlled trials (RCTs) comparing ALS with other agents was performed up to January 2013. DerSimonian and Laird meta-analysis was performed to obtain pooled relative risk (RR) from which efficacy of ALS and numbers needed to treat (NNT) were calculated. In a restricted analysis, pooled RRs where compared using a test of interaction to calculate ratio of relative risks (RRR). Meta-regression analysis was employed to explore sources of heterogeneity. Results: Sixteen RCTs involving 2016 individuals met the inclusion criteria. The efficacy of ALS in preventing CRBSI was 80% with NNT of 3 patients to prevent one CRBSI. The RR of CRBSI was significantly lower with ALS compared with heparin-only lock solution [RR {95% confidence interval (CI)} = 0.20 (0.13-0.31)]. With low dose (≤ 5 mg/ml) and high dose (40 mg/ ml) gentamicin-containing ALS, the RR (95% CI) of developing CRBSI was 0.03 (0.01-0.13) and 0.18 (0.03-0.98), respectively, with no significant difference [RRR (95% CI) = 0.2 (0.02-1.61), p = 0.126]. Heterogeneity was explained by a statistically significant association between rate of CRBSI and catheter days (p = 0.037). Conclusion: ALS are effective in preventing CRBSI. Low dose gentamicin should be preferred over high dose gentamicin as an ALS because it offers similar benefit in preventing CRBSI with lesser risk of toxicity from systemic leakage and subsequent development of drug resistance.