ED90 of Tegileridine Combined With Propofol for LMA Insertion

90% Effective Dose of Tegileridine Combined With Propofol for Inhibiting Laryngeal Mask Airway Insertion Responses in Patients of Different Ages: A Biased-Coin Sequential Allocation Dose-Finding Study

This is a prospective two-group dose-finding trial using biased-coin sequential up-and-down design. We plan to enroll 108 patients who need general anesthesia with laryngeal mask airway placement, divided into young group (18-64 years old) and elderly group (65 years old and older). All patients will receive tegileridine combined with fixed-dose propofol for anesthesia induction. The main goal is to find the 90% effective dose (ED90) of tegileridine that can fully block body movement, cough, tearing and unstable blood pressure/heart rate during laryngeal mask insertion. We will also record cough rate, hemodynamic changes, sedation depth and all perioperative adverse reactions to provide safe dosing reference for different age patients in clinical anesthesia.

Inclusion Criteria:

• Elective surgery requiring general anesthesia with laryngeal mask airway insertion
• Age ≥ 18 years
• American Society of Anesthesiologists (ASA) physical status I-III

Exclusion Criteria:

• At rest in the operating room, systolic blood pressure ≥ 160 mmHg or - diastolic blood pressure ≥ 110 mmHg or heart rate ≥ 110 bpm
• Continuous opioid medication for more than 2 weeks within half a year before surgery
• Known allergy or hypersensitivity to tegileridine or any study medication components
• History of psychiatric illness or inability to communicate effectively