EC

Purpose: Regarding anesthesia management for high-intensity focused ultrasound (HIFU) treatment of uterine adenomyosis, existing research is limited. While considered non-invasive, HIFU ablation carries risks such as thermal injury to adjacent structures like nerves if the focused energy deviates from the target. Therefore, the procedure requires that patients remain perfectly still while retaining sufficient consciousness to immediately report warning sensations like cutaneous burning or radiating leg pain. This unique requirement renders conventional anesthetic approaches inadequate. General or neuraxial anesthesia impair sensory feedback, while traditional intravenous sedation presents challenges in balancing analgesia with respiratory safety and patient communication. Epidural analgesia with low-concentration ropivacaine offers a potential solution due to its favorable sensory-motor dissociation, which can maintain analgesia and immobility while preserving the patient's ability to communicate. Previous studies support the efficacy of this approach, but the optimal drug concentration remains undefined. This study aimed to determine the median effective concentration (EC Patients and Methods: This prospective study ultimately included 29 patients with adenomyosis undergoing HIFU with intraoperative epidural analgesia. The epidural solution contained ropivacaine (concentrations determined through an up-and-down sequential method, starting at 0.06% for the first patient) and sufentanil 0.5 µg/mL. After a 5 mL test dose, a 15 mL bolus was administered, followed by 10 mL maintenance doses every 40 minutes. Successful analgesia was defined as an intraoperative visual analog scale (VAS) score < 4. Results: The EC Conclusion: These findings provide critical dose references for optimizing intraoperative analgesia during HIFU for adenomyosis.