The effect of magnesium sulfate on surgical field during endoscopic sinus surgery: A meta-analysis of randomized controlled trials Introduction: The benefits of magnesium sulfate for surgical field during endoscopic sinus surgery remain controversial. We conduct a systematic review and meta-analysis to explore the influence of magnesium sulfate versus placebo on surgical field during endoscopic sinus surgery. Methods: We search PubMed, EMbase, Web of science, EBSCO, and Cochrane library databases through November 2018 for randomized controlled trials (RCTs) assessing the effect of magnesium sulfate versus placebo on surgical field during endoscopic sinus surgery. This meta-analysis is performed using the random-effect model. Results: Four RCTs and 404 patients are included in the meta-analysis. Overall, compared with control group endoscopic sinus surgery, magnesium sulfate has remarkably positive impact on surgical field scores (MD = −1.76; 95% CI = −2.33 to −1.18; P < .00001), and intraoperative blood loss (MD = −89.09; 95% CI = −163.20 to −14.97; P = .02), but shows no markedly effect on surgery duration (MD = −7.08; 95% CI = −21.38 to 7.22; P = .33), fentanyl (MD = −0.64; 95% CI = −1.97 to 0.70; P = .35), and vecuronium (MD = −3.64; 95% CI = −10.99 to 3.70; P = .33). Conclusions: Magnesium sulfate exerts positive impact on surgical field and blood loss reduction for endoscopic sinus surgery.