Fospropofol Disodium ED95 for Elderly Spinal Anesthesia Sedation

95% Effective Dose (ED95) of Fospropofol Disodium for Adjunctive Sedation During Spinal Anesthesia in Elderly Patients Undergoing Lower Extremity Surgery

This study aims to determine the 95% effective dose (ED95) of fospropofol disodium, a new sedative drug, for adjuvant sedation during spinal anesthesia in elderly patients (aged 65 years and older) undergoing lower extremity surgery (e.g., hip/knee replacement, lower limb fracture fixation).

Fospropofol disodium, the only water-soluble propofol prodrug marketed in China, features mild effects on respiratory and circulatory systems, low injection pain, no lipid metabolism-related adverse reactions, and suitable duration of action-making it a promising sedative for elderly patients. However, clinical data on its use in adjuvant sedation during spinal anesthesia are lacking, with no reports on its effective dose in this specific scenario. This prospective sequential trial aims to determine the 95% effective dose (ED95) of fospropofol disodium for sedation induction and maintenance in elderly patients (≥65 years) undergoing lower extremity surgery with spinal anesthesia, providing evidence-based guidance for safe and rational clinical use.

Inclusion Criteria:

• Age ≥65 years, no gender restriction
• Scheduled for elective lower extremity surgery with spinal anesthesia
• ASA physical status classification Ⅰ-Ⅲ
• BMI 18.5-28.0
• Written informed consent obtained from patients or their guardians

Exclusion Criteria:

• Age <65 years；
• Non-lower extremity surgery or conversion to general anesthesia；
• ASA physical status classification Ⅳ or above；
• BMI <18.5 or >28.0；
• History of drug abuse or alcohol dependence；
• Preoperative use of sedative or analgesic drugs；
• Refusal to participate or inability to sign informed consent；
• Severe arrhythmia or myocardial infarction within 3 months；
• Severe liver or kidney dysfunction；
• Severe respiratory diseases；
• Coagulopathy；
• Uncorrected severe electrolyte disturbance；
• History of mental illness or cognitive impairment.