Effect of Combined Administration of Sevoflurane and Remimazolam on Emergence

• Laparoscopic oophorectomy or hysterectomy is a commonly performed gynecological surgery, and rapid recovery, pain management, prevention of postoperative nausea and vomiting are important factors determining early discharge and patient satisfaction. With the recent emergence of enhanced recovery after surgery (ERAS), various clinical studies are being conducted to improve the quality of patient recovery through decisions regarding anesthesia methods and agents, fluid administration, prevention of nausea and vomiting, and pain management during surgery.
• The method of inducing anesthesia with intravenous injection of anesthetic agents such as propofol followed by maintenance of anesthesia using inhalation anesthetics is generally performed as a method of general anesthesia. Inhalation anesthetics commonly used for maintenance of anesthesia can be easily administered and removed via ventilation, and they have the advantage of maintaining anesthesia depth relatively easily by monitoring parameters such as bispectral Index (BIS) and end-tidal gas concentration. However, it has the disadvantage of delaying recovery and increasing hospital stay due to postoperative nausea and vomiting, and it decreases average arterial pressure proportionally to the dose due to systemic vasodilation.
• Remimazolam (Byfavo Inj., Hana Pharm Col, Ltd., Seoul, Korea) is a benzodiazepine-class drug used for induction and maintenance of general anesthesia and for sedation during procedures. When remimazolam is used as a general anesthetic, it is rapidly metabolized by enzymes in the liver compared to propofol, resulting in a short context-sensitive half-life of 7.5 minutes and allowing for reversal with flumazenil. Additionally, it is known to induce fewer hemodynamic changes.
• There is research indicating that combining sevoflurane and propofol (target plasma concentration 1.2 mcg/mL) for general anesthesia in adult patients reduces arousal excitement and provides rapid recovery. However, in general anesthesia using desflurane or remimazolam, the time to tracheal extubation was longer in the remimazolam group. Furthermore, there is research suggesting that combining remimazolam with inhalation anesthesia during general anesthesia in pediatric patients can reduce the occurrence of emergence agitation after surgery, but the time to emergence is longer. However, there is currently no research on the effects of combining sevoflurane and remimazolam for general anesthesia in adult patients on postoperative arousal and recovery.

The objective of this study is to investigate whether there is a difference in the time to emergence from anesthesia and time to tracheal extubation in patients undergoing gynecologic and laparoscopic surgery under general anesthesia, comparing the concurrent administration of sevoflurane and remimazolam with the maintenance of anesthesia using sevoflurane alone.

Inclusion criteria

• Adult patients aged 19 to 70 undergoing gynecologic and laparoscopic surgery under general anesthesia
• Patients classified as American Society of Anesthesiologists (ASA) physical status classification I or II

• According to the American Society of Anesthesiologists (ASA) physical status classification:

Class I - Healthy patients without systemic disease Class II - Patients with mild systemic disease without functional limitation Class III - Patients with severe systemic disease that limits activity but is not incapacitating Class IV - Patients with incapacitating systemic disease that is a constant threat to life Class V - Moribund patients who are not expected to survive without the operation Class VI - Brain-dead patients for organ donation

Exclusion criteria

• Patients classified as ASA physical status classification III or above
• Pregnant women
• Patients with hypersensitivity to sevoflurane or other halogenated anesthetics, malignant hyperthermia, or a history of it in the patient or family
• Patients with preoperative impairment of consciousness or coma
• Patients undergoing emergency surgery or those who are hemodynamically unstable preoperatively
• Patients with a history of neuromuscular disorders or medication affecting neuromuscular function
• Patients who have taken sedatives (anxiolytics, hypnotics, antipsychotics, antidepressants, or sleeping pills) within 24 hours
• Patients receiving long-term benzodiazepine therapy
• Patients with alcohol or substance dependence
• Patients with allergy history to benzodiazepines or flumazenil
• Patients with genetic disorders such as galactose intolerance, Lapp lactase deficiency, or glucose-galactose malabsorption
• Patients with severe hypersensitivity reactions to dextran 40
• Patients with chronic renal failure requiring hemodialysis
• Patients with a history of acute angle-closure glaucoma