Advances in Acute Normovolemic Hemodilution: A Narrative Review

• ANH efficacy is context-dependent, varying by patient and surgical procedure. • ANH exerts organ-specific physiological impacts; kidneys are most sensitive to its hemodilution. • ANH has dual coagulation effects: in-vivo dilution vs. preserved ex-vivo clot function. • ANH requires meticulous fluid management and alters anesthetic drug pharmacokinetics. • Integrate ANH into multimodal patient blood management for its safe and effective use. Acute normovolemic hemodilution (ANH) is a blood conservation method aimed at reducing allogeneic blood transfusion. While it may reduce transfusion-related risks, its overall clinical efficacy is supported by an inconsistent evidence base. Recent high-quality trials have contributed to an ongoing debate regarding its routine utility, highlighting heterogeneity in outcomes across different surgical settings and patient populations. To clarify its role, this review provides a critical appraisal of the ANH literature. This review delineates its physiological mechanisms, synthesize the variable evidence across surgical specialties, and discuss its implications for anesthetic management.The aim is to equip clinicians with a balanced and evidence-informed perspective to support individualized clinical decision-making within the framework of modern patient blood management.