Effective Doses of Oliceridine Combined with Propofol for Painless Hysteroscopy: A Prospective Dose-Finding Study.

Background: The combination of oliceridine with propofol represents a new option for complete intravenous anesthesia in painless hysteroscopy. The purpose of this study was to determine the 95% effective dose (ED95) and the median effective dose (ED50) of oliceridine when combined with propofol for painless hysteroscopy. Methods: A total of 29 patients, aged between 18 and 60 years and classified as American Society of Anesthesiologists (ASA) I-II, were initially recruited for hysteroscopy. Subsequently, 26 of these patients were included in the final analysis. Before surgery, an intravenous dose of 0.02 mg/kg oliceridine, with a dose gradient of 0.002 mg/kg, was administered using Dixon's up-and-down method. Two minutes later, 2 mg/kg of propofol was administered. The oliceridine dosage for the following patient was increased by 0.002 mg/kg if the hysteroscopy failed (defined as poor cervical dilatation, problematic hysteroscopic placement, or a Ramsay Sedation Scale (RSS) score < 5 or any movement and frowning by the patient within 5 minutes). In contrast, the dosage was decreased by 0.002 mg/kg. At least seven crossovers had to occur before the test was stopped. The ED50 and ED95 of oliceridine in combination with propofol for hysteroscopy were determined using the probit analysis method. Results: The ED50 and ED95 of oliceridine with 95% CI were 0.0192 (0.0183-0.0216) mg/kg and 0.0237 (0.0214-0.0415) mg/kg, respectively. No patients experienced significant adverse effects. Conclusion: The study determined that the ED50 and ED95 of oliceridine in combination with propofol for painless hysteroscopy are 0.0192 mg/kg and 0.0237 mg/kg, respectively. Oliceridine at 0.0237 mg/kg provides safe and effective anesthesia when combined with propofol.