Please confirm that an ethics committee approval has been applied for or granted: Yes: I’m uploading the Ethics Committee Approval as a PDF file with this abstract submission

Background and Aims We aim to investigate the safety and feasibility of remimazolam-based monitored anesthesia care (MAC) in patients undergoing transurethral resection of bladder tumor (TURBT) guided by analgesia nociception index (ANI) monitoring, while comparing the net anesthesia time (anesthesia time excluding procedure time) between MAC and inhalation general anesthesia.

Methods In the remimazolam group, remimazolam was administered at a rate of 6 mg/kg/h until the loss of consciousness, followed by at a maintenance dose of 1 mg/kg/h, and adjusted. In the sevoflurane group, general anesthesia was induced with propofol 1-2 mg/kg and maintained with 1-2 minimum alveolar concentration sevoflurane. Following the loss of consciousness, laryngeal mask airway (LMA) insertion or endotracheal intubation was performed after administration of intravenous 0.3-0.6 mg/kg rocuronium. Remifentanil was administered using a target-controlled infusion (TCI) at effect-site concentration [Ce] of 3.0 ng/ml and adjusted to maintain the ANI scores in the range of 50-70 in both groups. The primary outcome was net anesthesia time, calculated by excluding the procedure time from the total anesthesia time.

Results Till now, 11 patients were enrolled. The net anesthesia time was significantly shorter in the remimazolam group than in the sevoflurane group (14±7 vs. 25±4 min, p=0.023). The operating room occupancy time was also significantly shorter in the remimazolam group than in the sevoflurane group (32 ± 10 vs. 49 ±11 min, p=0.039). The procedure time, time to loss of consciousness and regaining consciousness, admission day were similar between the groups.

Conclusions Remimazolam-based MAC proves to be a safer alternative for general anesthesia during TURBT.