Comparison of Efficacy of Clonidine Versus Dexamethasone as Adjuvants to 0.75% Ropivacaine in Ultrasound-Guided Popliteal Block for Lower Limb Surgeries: A Randomized Controlled Trial

Background: Peripheral nerve blocks provide effective postoperative analgesia for lower limb surgeries. The addition of adjuvants to local anesthetics can significantly prolong the duration of analgesia. However, the comparative efficacy of different adjuvants remains unclear. To compare the efficacy of clonidine versus dexamethasone Aims and Objective: as adjuvants to 0.75% ropivacaine in ultrasound-guided popliteal block for lower limb surgeries in terms of duration of analgesia, onset of sensory and motor regression, and hemodynamic stability. This Materials And Methods: prospective, randomized, double-blind study included 50 patients (ASA I-III, aged 15-55 years) undergoing lower limb surgeries. Patients were randomly allocated to receive either 0.75% ropivacaine with 8mg dexamethasone (Group DXM, n=25) or 0.75% ropivacaine with 100 g clonidine (Group CL, n=25) for ultrasound-guided popliteal block. Primary outcome was duration of analgesia. Secondary outcomes included onset of sensory regression, motor regression, pain scores using Visual Analog Scale (VAS), and hemodynamic parameters. The mean duration of analgesia w Results: as significantly longer in Group DXM compared to Group CL (14.53±1.41 vs 8.2±1.44 hours, p<0.001). Onset of sensory regression was delayed in Group DXM (14.2±1.18 vs 10.9±1.10 hours, p<0.001). Motor regression onset was also significantly delayed in Group DXM (19.7±1.87 vs 17.1±1.22 hours, p<0.001). VAS scores remained significantly lower in Group DXM up to 16 hours postoperatively. Hemodynamic stability was better maintained in Group DXM with significantly lower heart rate and blood pressure values. Dexamethasone as an adjuvant to 0.75% Conclusion: ropivacaine in ultrasound-guided popliteal block provides superior analgesia duration, delayed onset of block regression, and better hemodynamic stability compared to clonidine for lower limb surgeries.