Intravenous Dexmedetomidine in adult cardiac surgery: a protocol of an umbrella review

Introduction Dexmedetomidine has been widely used in cardiac surgery due to its unique effects such as anti - sympathetic, sedation, and analgesia. However, recent studies and meta-analyses have been shown mixed results on its safety and effectiveness, with some studies indicating possible risks. This study seeks to assess the quality, biases, and effectiveness of all existing systematic reviews on dexmedetomidine in adult cardiac surgery to offer clearer evidence-based insights. Methods A quantitative umbrella review will assess the impact of intravenous dexmedetomidine on outcomes in adult cardiac surgery, focusing on major adverse cardiovascular events, postoperative atrial fibrillation, acute kidney injury, delirium, and ICU stay duration. Relevant literature up to August 1, 2025, will be sourced from PubMed, Embase, Cochrane Database of Systematic Reviews, and Web of Science using a comprehensive search strategy. Two independent reviewers (XTJ and MY) initially screened study titles and abstracts, resolving any disagreements with a third reviewer (GYY). Full texts of studies passing this stage were evaluated by two other reviewers (YL and SJ) using set criteria. Data extraction, methodology quality assessment, and evidence level assessment were independently completed by two people (XHB and WW). The meta-analysis was grouped according to the patients' outcomes. Data conflicts and overlaps will be used updated methods like concordance correlation analysis (CCA). Evidence synthesis involved corrected overlap analysis and meta-analysis of original studies. Discussion This umbrella review expects to systematically assess the impact of perioperative intravenous Dexmedetomidine administration on the prognosis of adult cardiac surgery. Specific approaches were developed to address key challenges in conducting an umbrella review, including assessment tools of methodology and evidence quality of meta-analyses, methods to manage overlap between meta-analyses, clarified the beneficial or adverse effects of dexmedetomidine on adult cardiac surgery. Trail registration CRD420251128632