Effects of Remimazolam on Intraoperative Frontal Alpha Band Power Spectrum Density and Postoperative Cognitive Function in Older Adults Undergoing Lower Extremity Fractures Surgeries: A Randomized Controlled Trial.

Purpose: Low density of electroencephalogram alpha band power was reported to be associated with perioperative cognitive dysfunction. Few studies have conducted to explore the effects of remimazolam on intraoperative frontal alpha band power spectrum density in older adults. Here, we aimed to explore the impact of remimazolam on intraoperative frontal brain wave alpha band activity and postoperative cognitive function in older adults undergoing lower extremity fractures surgeries.

Methods: Patients undergoing elective general anesthesia for lower extremity fracture surgery were randomly allocated to remimazolam group (Group R) and midazolam group (Group M). Group R was induced with remimazolam bolus 0.1 mg/kg followed by a maintenance dose of 0.1 mg·kg^-1·h^-1 for general anesthesia. Group M was induced with midazolam 0.05 mg/kg followed by normal saline maintenance of 0.1 mL·kg^-1·h^-1. The rest anesthesia protocol was the same for both groups. Electroencephalogram data was recorded before anesthesia induction till the end of surgery. Cognitive function was assessed preoperatively, and at the first, third, fifth, and seventh day postoperatively.

Results: Compared with Group M, Group R had significantly higher intraoperative power spectral density of the frontal alpha band (P < 0.001), and significantly lower incidence of postoperative cognitive dysfunction at T₈ and T₉ (P = 0.031 and P = 0.017, respectively).

Conclusion: Remimazolam can increase frontal brain wave alpha band power spectrum density and improve postoperative cognitive function in older adults undergoing lower extremity fractures surgeries.