Methods: Eight databases, including MEDLINE, EMBASE, Science Direct, Scopus, Cochrane, CINAHL, Open Grey, and Dart-Europe, were systematically searched from the inception of the database up to August 21, 2020. Studies evaluating the effectiveness of thiamine on mortality rate in septic shock patients compared between thiamine and placebo were included. We used random-effects model to analyze the mortality with risk ratio (RR) and 95% confidence interval (95% CI). The subgroup and sensitivity analysis were performed to examine the influence of variables. Publication bias was considered using funnel plot, Begg's test, and Egger's test.

Results: A total of 3,658 studies were retrieved and reviewed. Five studies were included for meta-analysis. In random-effects meta-analysis of the randomized controlled trials, although not statistically significant, there was a trend which suggested that thiamine may reduce mortality rate in septic shock patients (RR, 0.96; 95% CI: 0.72-1.28, P = 0.774). The result of sensitivity and subgroup analyses also supported the suggestion that thiamine may decrease mortality in septic shock patients. The Begg's test (P = 0.624) and Egger's test (P = 0.777) revealed no publication bias.