Modified Dixon sequential method to determine the effective dose of alfentanil compounded with propofol for day-case hysteroscopy

Abstract

Background: Propofol combined with alfentanil is suitable for intravenous anesthesia for day-case hysteroscopy. Objective: To investigate the median effective dose (ED50) and 95% effective dose (ED95) of alfentanil compounded with propofol for day-case hysteroscopy. Design: In all, 29 patients who volunteered for painless hysteroscopy in 2022 were recruited. 1.5 mg/kg propofol was given as a sedative to all patients. The trial was conducted using the modified Dixon sequential method, with an initial dose of 10 μg/kg of alfentanil, and the subject’s alfentanil dose depended on whether the prior hysteroscopy had failed, which was defined as inadequate cervical dilatation and hysteroscope placement with the patient exhibiting body movement, frowning, or a MOAA/S score >1. If the hysteroscopy failed (i.e. a positive response), the subsequent subject’s alfentanil dosage was raised, and conversely (i.e. a negative response), the dose was decreased, with the adjacent dose ratio always being 1:1.2. The formal test begins with the first crossover wave and lasts until seven crossover waves materialize. Methods: The probit method was used to calculate the ED50, ED95, and corresponding 95% confidence intervals (CIs) of alfentanil compounded with propofol for hysteroscopy. Results: The ED50 and ED95 of alfentanil combined with propofol for day-case hysteroscopy were 5.701 (95% CI: 3.841–7.069) μg/kg and 8.817 (95% CI: 7.307–20.868) μg/kg, respectively. Conclusion: Alfentanil at 8.817 μg/kg in conjunction with propofol is a successful and safe approach for day-case painless hysteroscopy. Trial registration: The trial registry name: Modified sequential method to determine the half-effective dose of alfentanil compounded with propofol for ambulatory hysteroscopy. The URL of registration is https://www.chictr.org.cn/showproj.html?proj=171786 , where the full trial protocol can be accessed. Registration number: ChiCTR2200061619.

Median Effective Dose of Ciprofol Combined With Sufentanil for Inhibiting the Upper Gastrointestinal Endoscopic Placement Reaction in Elderly Patients

“…In this study, an equal difference increment/ decrement method was used to determine the dose for the next patient based on the dose used in the previous patient. There are two methods of increasing or decreasing the dose gradient of the test drug that are more commonly used in sequential testing, one is the equal proportional increase or decrease method 17 and the other is the equal difference increase or decrease method. 18,19 Equivariate increases and decreases make it easier to control the dose increases and decreases, facilitate the calculation and dosing of the next patient, save trial time and reduce the difficulty of dosing, and also shorten the study period.…”