Effect of Lidocaine Spray on the Sedative Dose of Remimazolam During Gastroscopy in Adults: A Prospective, Randomized Dose-Response Trial Using an Up-Down Sequential Allocation Method.

PURPOSE: To investigate the effect of oropharyngeal topical lidocaine spray on the sedative dose of remimazolam required for gastroscopy in adults. PATIENTS AND METHODS: Patients undergoing painless gastroscopy at our hospital were selected and randomly divided into a lidocaine spray group (Group L) and a control group (Group C) using a random number table method, with 25 patients enrolled in Group L and 24 patients enrolled in Group C. Patients in Group L received oropharyngeal spray containing lidocaine aerosol (approximately 16 mg of lidocaine per spray), with two sprays administered. Patients in Group C received oropharyngeal spray containing normal saline aerosol. At the start of sedation, alfentanil was intravenously injected at a dose of 3 μg/kg, followed by remimazolam administration using a sequential method. The initial intravenous dose of remimazolam was 0.2 mg/kg, with a dose adjustment gradient of 0.02 mg/kg. The median effective dose (ED50) of remimazolam for successful first-dose sedation during gastroscopy was calculated using probit regression analysis. RESULTS: The ED50 (95% confidence interval) of remimazolam in Group L was 0.149 (0.125-0.167) mg/kg, while that in Group C was 0.191 (0.147-0.217) mg/kg. The relative median potency between the two groups was 0.783 (95% CI: 0.381-0.959). In addition, no statistically significant differences were observed in hemodynamic changes or related adverse events between the two groups (P > 0.05). CONCLUSION: Lidocaine spray can be used in combination with remimazolam for gastroscopic examination to reduce the sedative dose of remimazolam during gastroscopy in adults.