Antithrombin for severe burn injury: a protocol for systematic review and meta-analysis Yuki Itagaki1), Mineji Hayakawa1),　Yuki Takahashi1) 1 Department of Emergency Medicine, Hokkaido University Hospital, Sapporo, Japan *Correspondence: Yuki Itagaki, Department of Emergency Medicine, Hokkaido University Hospital, Sapporo, Japan, 060-8638, Japan (e-mail: koaraninaritaizo@gmail.com). ORCID: 0000-0003-2133-2787 Introduction: Burn injury is one of the leading causes of death globally. Patients with severe burns are at high risk of activation of the coagulation system, which may lead to coagulopathy, organ dysfunction, and worsening of the burn site. Several previous studies reported that antithrombin might improve the mortality of severe burn injury. However, lack of high-quality randomized controlled trials as robust evidence, and clinical recommendations are lacking. Methods and analysis: We will conduct a systematic review and meta-analysis of administration of antithromibin for severe burn patients. We will include randomized controlled trials and observational studies. The intervention will be the supplementation of anticoagulation factors. The control group will be administered with ordinal therapy or a placebo. The primary outcome of the study is in-hospital mortality. We will search electronic databases such as MEDLINE (PubMed), Web of Science, and the Cochrane Central Register of Controlled Trials. We will apply uniform criteria for evaluating the risk of bias associated with individual RCTs and non-randomized trials based on the Cochrane risk of bias tool. We will assess the strength of evidence using the Grading of Recommendations Assessment, Development and Evaluation approach. Results: We will summarize the selection of the eligible studies using a PRISMA flowchart. The results will be presented in a table of summary of the evidence. The results of the meta-analysis will be depicted using figures and forest plots Conclusions: This systematic review will provide updated information on the efficacy of antithrombin therapy for severe burn injuries. To our knowledge, this is the first systematic review and meta-analysis that specifically focuses on treatments for coagulopathy of severe burn injuries.