1. Introduction
ADVERSE EVENTS, NEUROLOGICAL COMPLICATION
Delayed emergence from general anesthesia interferes with operating room (OR) management and increases adverse events such as delayed recovery of airway reflexes.Spinal surgery, which often involves older patients, requires intraoperative motor-evoked potential (MEP) monitoring to reduce perioperative neurological complications, which limits the use of inhaled anesthetics and muscle relaxants that interfere with MEP monitoring. Therefore, total intravenous anesthesia using propofol is recommended for anesthesia maintenance, and sufficient anesthesia depth must be maintained to achieve immobility without muscle relaxants during spinal surgery.Propofol is primarily metabolized and excreted by the liver and kidneys. Therefore, older patients are likely to have delayed emergence and require smaller doses than younger patients.Remimazolam is a new benzodiazepine that can be administered continuously and antagonized by flumazenil. This new intravenous anesthetic is an ultra-short-acting agent that enables more rapid induction and emergence than the conventional benzodiazepine midazolam. It has a similar structure to midazolam; however, it is rapidly metabolized by tissue esterases, primarily in the liver, and its metabolites are inactive.The purpose of this study was to compare the state of emergence in older patients who underwent spinal surgery under general anesthesia using remimazolam and propofol and to determine whether remimazolam-based anesthesia provides a more rapid emergence than propofol-based anesthesia. Since remimazolam is approved for general anesthesia only in Japan and Korea, and studies on the state of emergence from general anesthesia using this drug are still few, especially limited to older patients undergoing spinal surgery, we believe it is significant to report the results of this study using remimazolam.