Efficacy and safety of terlipressin infusion during liver surgery: a protocol for systematic review and meta-analysis

Introduction Liver disease causes 2 million deaths annually, accounting for 4% of all deaths worldwide. Liver surgery is one of the effective therapeutic options. Bleeding is a major complication during liver surgery. Perioperative bleeding and allogeneic blood transfusion may deteriorate the prognosis. Terlipressin (TP), a synthetic analogue of the antidiuretic hormone, may reduceblood loss during abdominal surgery. Several clinical centres have attempted to use TP during liver surgery, but the evidence for its effectiveness in reducing blood loss and the need for allogeneic blood transfusion, as well as its safety during the perioperative period, remains unclear. The aim of this systematic review and meta-analysis is to evaluate the efficacy and safety of TP in reducing blood loss and allogeneic blood transfusion needs during liver surgery. Methods and analysis We will search PubMed, EMBASE, the Cochrane Library and Web of Science for studies on perioperative use of TP during liver surgery from inception to July 2023. We will limit the language to English, and two reviewers will independently screen and select articles. The primary study outcomes are estimated blood loss and the need for allogeneic blood transfusion. Secondary outcomes include operating time, intensive care unit stay, length of stay, intraoperative urine output, acute kidney injury rate, postoperative complications, hepatic and renal function during follow-up, and TP-related adverse effects. We will include studies that met the following criteria: (1) randomised controlled trials (RCTs), cohort studies or case-control studies; (2) the publication time was till July 2023; (3) adult patients (>= 18 years old) undergoing elective liver surgery; (4) comparison of TP with other treatments and (5) the study includes at least one outcome. We will exclude animal studies, case reports, case series, non-original articles, reviews, paediatric articles, non-controlled trials, unpublished articles, non-English articles and other studies that are duplicates. We will use Review Manager V.5.3 software for meta-analysis and perform stratification analysis for the study quality of RCTs based on the Jadad score. For cohort or case-control studies, the study quality will be analysed based on Newcastle-Ottawa Scale scores. Grading of Recommendations, Assessment, Development and Evaluation will be used to assess confidence in the cumulative evidence. For primary outcomes, we will conduct subgroup analyses based on meta-regression. We will also perform leave-one-out sensitivity analyses to evaluate the effect of each individual study on the combined results by removing the individual studies one by one for outcomes with significant heterogeneity. The protocol follows the Cochrane Handbook for Preferred Reporting Items for Systematic Reviews and Meta-Analysis Protocols guidelines. Ethics and dissemination This study is a secondary analysis of existing data; therefore, it does not require ethical approval. We will disseminate the results through peer-reviewed publications.