Abstract:Esketamine ，the S-enantiomer of ketamine ，demonstrates significant advantages in the perioperative management of elderly patients owing to its unique N-methyl-D-aspartate receptor antagonism and multi-target pharmacological effects. This article systematically reviews the current application status of subanesthetic dose of esketamine（clinically usually referring to a single intravenous bolus dose of <0.5 mg/kg）in the elderly population，covering key areas such as optimization of perioperative analgesia and sedation，maintenance of cardiovascular and respiratory functions，prevention of perioperative neurocognitive disorders，antidepressant effects，and sleep improvement. Future research directions are also discussed，including individualized dosing regimens and long - term safety assessments，to advance the development of precision anesthesia practices.