Comparison of Intrathecal Bupivacaine with Clonidine Versus Intrathecal Bupivacaine with Fentanyl for Post-operative Pain Treatment in Lower Limb Procedures

Background: One of the anaesthesiologist's key goals during spinal anaesthesia is to keep the body physiology as close to normal as feasible. As we all know, subarachnoid block causes significant hemodynamic changes, especially in trauma and elderly individuals. Sympathetic nervous system denervation, skeletal muscle weakness, or loss of proprioception are not linked to neuraxial opioids. They primarily operate on the receptors found in the substantia gelatinosa of the spinal cord to exert their synergistic analgesic impact on visceral pain. Opioids and local anaesthetics delivered intrathecally have a powerful synergistic analgesic effect. A 2 adrenergic agonist, Clonidine is sometimes used as a local anaesthetic adjuvant with mixed effects. The effects of intrathecal Clonidine vs Fentanyl with 0.5 percent hyperbaric bupivacaine on postoperative analgesic duration and adverse effects were compared.

Objectives: The purpose of this study was to compare the efficacy of 0.5 percent hyperbaric bupivacaine with Clonidine (75 gs) vs Fentanyl (25 gs) for spinal anaesthesia in patients undergoing lower limb procedures, as well as the postoperative pain alleviation and adverse effects in both groups.

Methods: This was a prospective study involving 80 patients who were scheduled for elective lower limb surgery under spinal anaesthesia. The participants were randomly assigned to one of two groups: Group C (15mg 0.5 percent bupivacaine + 75gs Clonidine) or Group F (15mg 0.5 percent bupivacaine + 25gs Fentanyl).

Results: We discovered a time delay in the start of sensory and motor block in group C after assessing the outcomes of our investigation. Group C's sensory and motor block lasted significantly longer compared to group F. The average duration of analgesia in groups C and F was 234.7529.71 minutes and 170.8732.38 minutes, respectively. Compared to group C, the demand for rescue analgesics was higher in group F throughout 24 hours. Bradycardia affected 12 individuals in group C, while pruritus affected 12 patients in group F. Five of the patients in group F experienced nausea.

Conclusion: In compared to 25gs Fentanyl, adjuvant use of Clonidine 75gs with hyperbaric bupivacaine prolongs the duration of both sensory and motor blockage, as well as the length of analgesia postoperatively, without generating substantial hemodynamic compromise or other side effects.