Study 2: Multiple-needle subcutaneous injection
nerve block
Forty-one subjects were selected to receive the multineedle subcutaneous injection and were randomly divided into the 150, 230, 300, 350 and 400 mg RODD groups (n = 6~8) and the ropivacaine hydrochloride injection (RHI) 150 mg group (n = 3). Each subject received a subcutaneous injection of RODD or RHI. The abdomen was divided into four areas by drawing horizontal and vertical lines through the navel, as shown in One area was randomly selected and marked as 1, while the other areas were marked clockwise as 2~4. Areas 1~3 were administered with RODD, and area 4 was the blank control for the nerve block test. A point in each region was selected as the center of the circle (the distance between the two centers was more than 8 cm), and the optimal block range and dose were obtained via the single-needle subcutaneous injection in Number of needles in the group = total dose of the group/optimal dose.Number of needles on circle 1 or 2 = the number of needles on each group/3.The remaining needles were allocated to the third circle. The needles on the circumference were evenly distributed. The intensity of the nerve block in the abdominal injecting area was measured in all subjects at different times after administration. The subjects were hospitalized for 72 h and followed up for 7 days after discharge.As shown in 