Median Effective Volume of 0.2% Ropivacaine for Ultrasound-Guided Axillary Brachial Plexus Block in Children Aged 6-10 Years: A Prospective Dose-Finding Study Using Up-and-Down Sequential Allocation.

The initial volume of ropivacaine (0.2%) was 0.5 mL/kg, adjusted by 0.05 mL/kg based on the previous patient's response.

The study continued until seven inflection points were observed from failure to success.

Patient demographics, postoperative pain scores, and adverse events were monitored.

No adverse events were observed during the perioperative period.