Abstract:

AIM: To observe the Ropivacaine treatment with lumbar plexus block rat hind limbs pain of chronic ischemia.   METHODS: Lumbar plexus of Normal SD rats were separated to induce neural discharge. Effects of different concentrations of Ropivacaine (0.025%, 0.05%, 0.075%, 0.1% and 0.125%) on neural discharges were then observed to determine the best concentration. A total of 39 healthy SD healthy adult rats were randomly divided into the normal group, ischemic group and ischemia+block group（n=13）. Chronic skeletal muscle ischemia model were prepared with unilateral femoral artery cannula, block lumbar plexus. One week after ischemia, histamine and substance P of the rat peripheral blood were observed by ELISA, pain threshold was determined by hot plate method, gastrocnemius was observed in paraffin section through HE staining. RESULTS: 0.075% Ropivacaine was the best block concentration. The rat pain threshold was significant different between groups (P<0.05) except normal group vs. ischemia +block group; pain threshold of the ischemia+block group increased more significantly than the ischemia group. The rat serum histamine, substance P were significant different between groups (P<0.05); histamine and substance P of the ischemia+block group decreased more significantly than the ischemia group. CONCLUSION: Lumbar plexus block with Ropivacaine treatment can effectively alleviate ischemia pain in rats.

Key words: ropivacaine, lumbar plexus block, pain of chronic ischemia