In recent years, there has been a growing demand for reducing discomfort during gastrointestinal endoscopy. In Japan, remimazolam, a new ultra-short-acting benzodiazepine sedative, has been approved for insurance coverage, and its usefulness in promoting earlier awakening compared to conventional midazolam has been reported. The purpose of this study was to retrospectively compare the sedative effects, awakening and recovery times, and safety of midazolam (M group), remimazolam (R group), and propofol (P group) during lower gastrointestinal endoscopy at a single local private clinic. Additionally, we aimed to investigate whether early awakening facilitated by these sedatives contributed to a reduction in staff overtime hours.

This was a single-center, retrospective study. A total of 121 cases of lower gastrointestinal endoscopy performed at our clinic between September 19, 2025, and November 7, 2025, were included. Patients were categorized into three groups based on the sedative used: M group, R group, and P group. We compared the sedative effect, the time from the end of the endoscopy to discharge from the recovery room, and the incidence of complications. Furthermore, we compared staff overtime hours during the two-month periods of September-October 2022 (when midazolam was primarily used) and September-October 2025 (when remimazolam was increasingly utilized).

 A total of 121 cases were included, with examinations performed by three endoscopists. The M group consisted of 76 cases (mean age 65.0 years, 44.7% male), the R group 27 cases (mean age 56.4 years, 44.7% male), and the P group 18 cases (mean age 49.7 years, 33.3% male). The mean examination times were 12.5 minutes for the M group, 11.9 minutes for the R group, and 13.7 minutes for the P group, with no significant difference observed among the three groups.

Regarding sedative effect, the proportion of patients who reported "no memory at all" was 100% in the M group, 66.7% in the R group, and 72.2% in the P group. Those who reported "some memory" were 0%, 33.3%, and 27.8%, respectively. The M group showed a significantly stronger sedative effect compared to both the R group and the P group (p < 0.05). No significant difference was found between the R group and the P group.

The mean time to discharge from the recovery room was 143.1 minutes for the M group, 18.0 minutes for the R group, and 12.7 minutes for the P group. The M group had a significantly longer recovery time compared to both the R group and the P group (p < 0.05). Furthermore, the R group also had a significantly longer recovery time compared to the P group (p < 0.05).

Regarding complications, one case of hypotension and vomiting was observed in the M group, and one case of hypotension in the P group. No complications were observed in the R group.

The average overtime hours for six staff members at our clinic were 541.5 minutes in September-October 2022 and 438.5 minutes in September-October 2025. Although there was a trend towards decreased overtime hours, no statistically significant difference was observed (ｐ＝0.18).

 The propofol group exhibited the shortest time to discharge from the recovery room. The remimazolam group demonstrated a significantly shorter recovery time than the midazolam group and could be used without complications. In terms of sedative effect, the midazolam group was superior. In the initial cases of remimazolam use in this study, some cases showed insufficient sedative effect, possibly due to initial unfamiliarity or dosage setting. However, its usefulness in promoting earlier awakening was suggested. Future challenges include increasing the number of cases, extending the period of use, and establishing optimal dosing for remimazolam. Although staff overtime hours showed a decreasing trend, a statistically significant difference was not observed, potentially due to factors such as an annual increase in the number of examinations.