Abstract:Objective To compare the anesthetic effect of different doses of esketamine combined with propofol in elderly patients underwent endoscopic retrograde cholangiopancreatography (ERCP), and explore the appropriate dose.Methods 105 elderly patients were selected for ERCP. The patients were divided into 3 groups with 35 cases in each group by random number table method. E1 group, E2 group and E3 group were given esketamine 0.15, 0.35 and 0.50 mg/kg, respectively, and were given propofol 1.00 mg/kg intravenous injection 15 s later. Heart rate (HR), mean arterial pressure (MAP), and percutaneous arterial oxygen saturation (SpO2) were recorded after left lateral position (T0), at successful induction (T1), endoscope through larynx (T2), sphincter insertion or incision (T3), and at recovery (T4). Operation duration, intraoperative propofol dosage, anesthesia recovery time ,visual analogue scale (VAS) score 15 min after anesthesia recovery and occurrence of adverse reactions were recorded.Results Compared with T0, HR and MAP decreased at T1, T2, T3 and T4 time point in E1 group, HR and MAP increased at T1, T2, T3 and T4 time point in E3 group, the differences were statistically significant (P < 0.05); HR and MAP had no significant changes at T1, T2,T3 and T4 time point in E2 group (P > 0.05); Compared with group E3, HR and MAP decreased at T1, T2, T3 and T4 time point in E1 group and E2 group, and E1 group was lower than E2 group, the differences were statistically significant (P < 0.05); There were no significant difference in SpO2 at different time points between the three groups (P > 0.05); Compared with E1 group, the dosage of propofol in E2 group and E3 group was decreased, and E3 group was significantly less than E2 group, with statistical significance (P < 0.05). Compared with E3 group, the recovery time of E1 group and E2 group was shorter, and E2 group was shorter than E1 group, the differences were statistically significant (P < 0.05). Compared with E1 group, pain VAS score 15 min after recovery in E2 group and E3 group was lower, and E3 group was lower than E2 group, the differences were statistically significant (P < 0.05). There was no significant difference in operation time among 3 groups (P > 0.05). The incidence of hypoxemia, respiratory depression and hypotension in E1 group were higher than that in E2 group and E3 group, the difference was statistically significant (P < 0.05). The incidence of psychomimetic symptoms and visual disturbance in E3 group was higher than that in E1 group and E2 group, the difference was statistically significant (P < 0.05). There were no significant differences in the incidence of dizziness and nausea vomiting among the 3 groups (P > 0.05).Conclusion 0.35 mg/kg esketamine combined with propofol in the operation of ERCP in elderly patients, respiratory circulation is more stable, and adverse reactions do not increase.