Comparison of clonidine versus fentanyl as an adjuvant to intrathecal ropivacaine for major lower limb surgeries: A randomized double-blind prospective study

Background: Ropivacaine is a newer local anesthetic, proven to have a better safety margin than bupivacaine and lignocaine. While maintaining this advantage and improving the intraoperative quality of anesthesia, the use of analgesic adjuvants has been proven to be valuable. Aim: To compare the efficacy of clonidine and fentanyl as adjuvants to intrathecal isobaric ropivacaine for major lower limb surgeries. Settings and Designs: Randomized double-blind control trial. Materials and Methods: Seventy patients were randomly divided in two groups. Ropivacaine-Clonidine group (RC) received 60 mcg of clonidine with 15 mg of 0.5% isobaric ropivacaine, Ropivacaine Fentanyl group (RF) received 25 mcg of fentanyl with 15 mg of 0.5% isobaric ropivacaine intrathecally. The onset and duration of sensory-motor block were recorded. The total analgesia time, sedation score, hemodynamic parameters, and side-effects were noted. Statistical Analysis: SPSS statistical package was used for statistical analysis. Paired and unpaired t-test, analysis of variance and chi-square test were used for statistical calculation. Result: The duration of sensory block in RC (329.42 ± 33.86), RF (226 ± 46.98), and motor block in RC (248.51 ± 55), RF (212.60 ± 43.52) out lasted the duration of surgery (125.61 + 64.46). In clonidine group, there was significant prolongation of sensory block (P < 0.001), motor block (P < 0.01) and the total analgesia time (P < 0.001). Hypotension and bradycardia occurred in 8.6% patients in clonidine group, whereas pruritus was experienced by 8.6% patients in fentanyl group. Conclusion: Ropivacaine when combined with clonidine or fentanyl provided adequate subarachnoid block for major surgeries, wherein clonidine has advantage over fentanyl as it increased the duration of subarachnoid block and prolonged the postoperative analgesia