Comparision of 0.25% Bupivacaine Vs 0.25% Bupivacaine and 0.5mcg/kg Dexmedetomidine in USG-guided Adductor Canal Block for Post-operative Pain Relief after Knee Replacement Surgery

This prospective, randomized clinical study will compare the efficacy of 0.25% Bupivacaine alone versus 0.25% Bupivacaine with 0.5 mcg/kg Dexmedetomidine in ultrasound-guided adductor canal block (ACB) for postoperative analgesia in unilateral total knee replacement (TKR) surgery. A total of 120 patients (ASA I–III, aged 40–85 years) undergoing elective unilateral TKR under spinal anaesthesia will be recruited and randomized into two groups (n=60 each).

Group B will receive 20 ml of 0.25% Bupivacaine, while Group D will receive 20 ml of 0.25% Bupivacaine with 0.5 mcg/kg Dexmedetomidine for ACB. Postoperative pain will be assessed using the Visual Analogue Scale (VAS) at 4, 8, 12, and 24 hours. Outcomes measured include:

• Duration of analgesia (time to first rescue analgesic)
• Total opioid (Tramadol) consumption in 24 hours
• Incidence of adverse effects (bradycardia, hypotension, sedation, nausea, vomiting, motor blockade, urinary retention)
• Patient satisfaction scores

Statistical analysis will involve t-test, Mann–Whitney U, repeated measures ANOVA, and Chi-square/Fisher’s exact test as appropriate, with p < 0.05 considered significant.

The study aims to determine whether the addition of Dexmedetomidine prolongs analgesia, reduces opioid requirement, and improves patient satisfaction without significant adverse effects, thereby contributing to enhanced recovery protocols after TKR.