Abstract: Objective To investigate the anesthetic therapeutic effect of ciprofol combined with remimazolam in painless gastroscopy and to explore its approperiate dose. Methods This study selected 800 patients who received painless gastroscopy in our hospital from February 2024 to December 2024. They were randomly divided into a control group and groups A1, A2, and A3, with 200 patients in each group. The control group patients were induced with remimazolam anesthesia （0.3 mg/kg）, Groups A1, A2, and A3 were induced with 0.20, 0.25, and 0.30 mg/kg ciprofol combined with 0.15 mg/kg remimazolam anethesia. Comparisons were conducted on the anesthesia induction time, gastrointestinal endoscopy duration, awakening time, directional force recovery time, heart rate, blood pressure, blood oxygen saturation, and incidence of adverse reactions. Results The success rate of sedation in Group A2 was significantly higher than that in the control group and Group A1 （P<0.05）, and there was no significant difference compared to Group A3 （P>0.05）. The duration of gastrointestinal endoscopy in Group A2 was significantly shorter than that in the control group and Group A1 （P<0.05）, and there was no significant difference compared to Group A3 （P>0.05）. The awakening time and directional force recovery time in Group A2 were significantly shorter than those in the control group and Group A3 （P<0.05）, and there was no significant difference compared to Group A1 （P<0.05）. The heart rates at loss of ciliary reflex after induction of anesthesia （T1） and at the begining of gastrointestinal endoscopy （T2） of the four groups of patients were all significantly reduced compared to 5 min before pre-anethesia （T0） （P<0.05）, and the decrease in heart rate in Group A2 was significantly lower than those in the control group, Group A1, and Group A3 （P<0.05）. The heart rate in Group A3 at the end of surgery （T3） was significantly lower than those in the control group, Group A1, and Group A2 （P<0.05）, while there was no significant difference between the control group, Group A1, and Group A2 （P>0.05）. The blood pressure values at T1 and T2 of the four groups of patients were significantly lower than those at T0 （P<0.05）, and the decrease in blood pressure in Group A2 was significantly lower than those in Groups A1 and A3 （P<0.05）. The blood pressure in Group A3 at T3 was significantly lower than those in the control group, Group A1, and Group A2 （P<0.05）, and there was no significant difference between the control group, Group A1, and Group A2 （P>0.05）. The blood oxygen saturation levels at T1 and T2 of the four groups of patients were significantly reduced compared to T0 （P<0.05）. The decrease in blood oxygen saturation level in Group A3 was significantly higher than those in the control group, Group A1, and Group A2 （P<0.05）. The blood oxygen saturation level at T3 in Group A3 was significantly lower than those in the control group, Group A1, and Group A2 （P<0.05）, while there was no significant difference between the control group, Group A1, and Group A2 （P>0.05）. The incidence of adverse reactions in Group A2 （10.00%） was significantly lower than those in the control group （21.00%）, Group A1 （12.00%）, and Group A3 （13.00%） （χ²=11.408, P<0.05）. Conclusion The combination of 0.25 mg/kg ciprofol and 0.15 mg/kg remimazolam in painless gastroscopy can exert the same sedative effect of ciprofol at high doses, which is beneficial for maintaining stable vital signs of patients without causing significant impact on their breathing, while reducing the occurrence of adverse reactions.

Key words: Ciprofol, Remimazolam, Painless gastroscopy, Painless colonoscopy, Adverse reactions