2014. To study the efficacy of ropivacaine (0.75%) with or without butorphanol as an adjuvant in single shot epidural anaesthesia in lower limb orthopedic surgeries. International Journal of Biomedical Research. 5, 12 (Dec. 2014), 725–730. DOI:https://doi.org/10.7439/ijbr.v5i12.847.