Comparison of Intrathecal Clonidine and Fentanyl as Adjuvant to Hyperbaric Bupivacaine in Subarachnoid Block for Lower Limb Orthopedic Surgery

BACKGROUND: Many studies are there using adjuvants such as clonidine and fentanyl with bupivacaine in the subarachnoid block for prolonging postoperative analgesia. However, literature is divided regarding the dosage and efficacy of both intrathecal adjuvants. Furthermore, these adjuvants have their own side effects. Hence, search for ideal intrathecal adjuvant between clonidine and fentanyl to bupivacaine goes on. AIM: The aim of the present study was to compare the effect of intrathecal clonidine and fentanyl as adjuvant to bupivacaine in the subarachnoid block for lower limb orthopedic surgery. MATERIALS AND METHODS: It was a prospective randomized study in which eighty patients posted for lower limb orthopedic surgery were divided into two groups of forty each. Group C – Received intrathecal hyperbaric bupivacaine (2.5 ml) +50 μg clonidine (diluted to 0.5 ml). Group F – Received intrathecal hyperbaric bupivacaine (2.5 ml) + fentanyl 25 μg (diluted to 0.5 ml). Duration of postoperative analgesia, sensory and motor block characteristics, hemodynamic parameters, and side effects were recorded and analyzed. RESULTS: Time for first dose of rescue analgesic was delayed in Group C (510.84 ± 24.10 min) in comparison to Group F (434.95 ± 19.16 min) which was statistically significant (P < 0.001). Duration of sensory and motor block was significantly prolonged in Group C compared to Group F (P < 0.001). Sedation was more in Group C than Group F (P < 0.001). Other block characteristics, hemodynamic, and side effects were comparable in both groups. CONCLUSION: Intrathecal clonidine as adjuvant to hyperbaric bupivacaine provided prolonged postoperative analgesia with more sedation in comparison to intrathecal fentanyl.