Dexamethasone versus Clonidine as Adjuvants to Ropivacaine in Popliteal Sciatic Nerve Blocks for Postoperative Analgesia in Foot and Ankle Surgeries: A Randomised Clinical Study

Introduction: Effective postoperative pain management is crucial in foot and ankle surgeries to enhance patient comfort and recovery. Popliteal Sciatic Nerve Blocks (PSNBs) are particularly useful in this context, as they provide site-specific, long-lasting analgesia with minimal systemic side effects, offer motor-sparing benefits, and facilitate early postoperative mobilisation. When combined with adjuvants like dexamethasone or clonidine, they may significantly improve the quality and duration of pain relief. Aim: To compare the analgesic efficacy, sensory and motor blockade, haemodynamic variability, and patient satisfaction when dexamethasone and clonidine are used as adjuvants to ropivacaine in PSNBs for patients undergoing foot and ankle surgeries. Materials and Methods: A prospective, randomised, double-blind trial was conducted in the department of Anaesthesiology, Dr. DY Patil Medical College and Research Centre, Pimpri, Maharashtra, India from March 2024 to March 2025 on 50 American Society of Anaesthesiologists (ASA) I and II patients aged 18-75 years undergoing elective foot and ankle surgery. Using a computergenerated randomisation sequence, patients were randomly assigned to two equal groups (n=25 each). Group RD received 28 mL of 0.5% ropivacaine with 2 mL (8 mg) dexamethasone, while Group RC received 28 mL of 0.5% ropivacaine with 2 mL (100 µg) clonidine. All blocks were administered under ultrasound guidance via the lateral approach. The primary outcome was the duration of analgesia, while secondary outcomes included Visual Analogue Scale (VAS) scores, durations of sensory and motor blocks, haemodynamic variability, and patient satisfaction. Statistical analysis was performed using independent t-tests and Chi-square tests, with p<0.05 considered significant. Results: Group RD demonstrated significantly prolonged analgesia (24.24±2.18 hours) compared to Group RC (18.00±2.45 hours, p<0.001). VAS scores were significantly lower in Group RD after 12 hours postoperatively (2.08±0.49 vs 3.36±0.49, p<0.001). The duration of the sensory block was 21.80±2.94 hours in Group RD versus 14.16±2.94 hours in Group RC (p<0.001), and the motor block duration was 21.36±4.48 hours versus 18.96±4.48 hours, respectively (p=0.03). Haemodynamic variability was comparable across groups, with no adverse effects, and patient satisfaction was higher in the dexamethasone group, though this was not statistically significant. Conclusion: Dexamethasone, when used as an adjuvant to ropivacaine in PSNBs, provides superior and longer-lasting analgesia, extended block duration, and better pain control compared to clonidine, with excellent safety and tolerability