Frequency and characteristics of patients with bispectral index values of 60 or higher during the induction and maintenance of general anesthesia with remimazolam

Abstract

In Korea, the approved anesthetic regimen of remimazolam starts with 6 mg/kg/h or 12 mg/kg/h until loss of consciousness, followed by maintenance at 1–2 mg/kg/h. Some patients receiving remimazolam for general anesthesia experience occasional difficulty maintaining bispectral index (BIS) value ˂ 60. This retrospective study aimed to analyze the data from patients undergoing elective surgery under remimazolam based-general anesthesia to determine the frequency and physical characteristics of patients with BIS values ˂ 60. The criterion was established for patients with a poorly maintained BIS value < 60. The frequency and physical characteristics of patients who satisfied this criterion were investigated through their medical records. The modified Brice interview was conducted within 24 h after surgery. Among the 1500 patients included in the analysis, 61 (4.1%) met the criteria for BIS ˂ 60. Based on the modified Brice interview, none of the patients with poorly maintained BIS ˂ 60 complained of intraoperative awareness based on the modified Brice interview or exhibit specific physical characteristics. These patients accounted for less than 5% of the total population studied. Notably, physical characteristics alone are insufficient to predict such patients before surgery.

Target-controlled infusion of remimazolam effect-site concentration for total intravenous anesthesia in patients undergoing minimal invasive surgeries

“…Notably, their study reported no signs of intraoperative awakening or postoperative recall, despite elevated BIS values ( 18 ). Similarly, a study on a Korean cohort ( n = 1500) found that in approximately 4.1% of patients, the BIS did not fall below 60, even when remimazolam was administered at the maximum recommended dose for the induction or maintenance of anesthesia ( 20 ). These findings underscore the need for further research in diverse clinical settings to determine the optimal BIS range for remimazolam-induced general anesthesia.…”

Remimazolam and Remifentanil Anesthetics for an Adolescent Patient with Stiff-Person Syndrome: A Case Report

“…11 Although a few studies have reported on BIS in remimazolam anesthesia, several previous findings indicate that most patients have no memory formation during general anesthesia with remimazolam at the level associated with a BIS of >60. 13,14 Kim et al 15 also demonstrated that neither explicit nor implicit memory formation occurs in patients under general anesthesia with remimzolam at BIS levels between 60 and 80. Therefore, this patient's anesthetic depth with remimazolam was most likely sufficient based on the electroencephalographic signature and her lack of complaint of any intraoperative awareness, suggesting that remimazolam could be useful as an anesthetic for patients with SPS.…”