Onset, duration, and intensity of nerve block
The onset time of nerve block shortened with increasing RODD dose, and the time of the 400 mg group was the fastest, with a median of 0.42 h in all test areas. The duration of the nerve block was dose-independent, and the median of the 400 mg RODD group was 35.7~47.7 h. When the scores of nerve block intensity were greater than 4 (>level 1), the analgesic rate of the 150~400 mg RODD groups were 100%. When the scores of nerve block intensity were greater than or equal to 5 (≥level 2). the analgesic rates of the 150, 230, 300, 350, and 400 mg RODD groups were 13.9%, 22.5%, 32.8%, 30.8%, and 42.9%, respectively, which was positively correlated with the dose of RODD. Finally, in the scores of nerve block intensity greater than and equal to 6 (level 3), the analgesic rate of the RODD groups ranged from 0.99% to 3.6%, a small percentage with no significant dose correlation. Therefore, the highest nerve block intensity was found in the 400 mg RODD group, and the distance between two injection sites on the circumference was 21.5±1.5 mm (