Etomidate and Ciprofol for Induction in CABG Under Cardiopulmonary Bypass: Mechanistic Rationale, Evidence Gaps, and...

Patients undergoing coronary artery bypass grafting (CABG) with cardiopulmonary bypass (CPB) are exposed to substantial perioperative stress, inflammation, and perfusion vulnerability, which may increase the risk of postoperative acute kidney injury (AKI) and postoperative delirium (POD). Although anesthesia induction is brief, it can influence blood pressure, vascular responsiveness, vasopressor exposure, cerebral oxygenation, and tissue perfusion. Etomidate is widely used in high-risk patients because of its hemodynamic stability, but it inhibits adrenal 11β-hydroxylase and attenuates the cortisol stress response. Ciprofol, a newer intravenous anesthetic, has shown favorable induction hemodynamics and less injection pain in some studies; however, current evidence largely comes from propofol comparisons, non-CABG populations, or process outcomes. No randomized evidence directly compares ciprofol with etomidate in adults undergoing CABG with CPB using AKI or POD as core outcomes. Thus, the superiority of either agent for organ outcomes is unproven. This narrative review summarizes the mechanistic rationale and evidence gaps and proposes standardized design considerations for future high-quality clinical trials. Future studies should use standardized Kidney Disease: Improving Global Outcomes AKI criteria and Confusion Assessment Method (CAM) or CAM‒intensive care unit delirium assessment while controlling CPB management, transfusion, vasopressor use, sedation, analgesia, and perioperative steroid exposure. This review aims to construct testable clinical hypotheses and provide a rationale for future trials, rather than to determine the absolute clinical superiority of either agent.