Combined Intrathecal Dexmedetomidine and Adductor Canal Block for Analgesia in Total Knee Arthroplasty: A Randomized Controlled Trial.

Abstract

Pain management following total knee arthroplasty (TKA) is critical for enhancing outcomes such as minimizing opioid consumption and hospital stay, overall function, and rehabilitation. To evaluate the effectiveness of combined intrathecal dexmedetomidine (ITD) and adductor canal block (ACB) in relieving post TKA pain. Double-blind, randomized controlled trial. KafrElsheikh University, Kafrelsheikh, Arab Republic of Egypt. A total of 75 patients, aged 18 to 75, who underwent TKA under spinal anesthesia participated in this double-blind, randomized controlled trial.. Three equal sets of patients were formed. Group ITD patients received 15 mg of hyperbaric bupivacaine in 3 mL via intrathecal injection, with 5 μg of dexmedetomidine (DEX) in 0.5 mL (total volume 3.5 mL) and an ACB with 20 mL of 0.9% saline. Group ACB patients received an intrathecal injection containing 15 mg of hyperbaric bupivacaine along with 0.5 mL of saline and an ACB with 20 mL of 0.25% bupivacaine. Group ITD+ACB patients received 15 mg of hyperbaric bupivacaine in 3 mL via intrathecal injection, with 5 μg in 0.5 mL of DEX and an ACB using 20 mL of 0.25% bupivacaine. The amount of morphine taken in the first postoperative 48 hours was the primary outcome. Compared to Group ITD and Group ACB, the total amount of morphine needed in the first postoperative 24 and 48 hours was significantly lower in Group ITD+ACB, and in group ACB compared to group ITD (P < 0.05). Visual Analog Scale pain scores were markedly reduced in Group ITD+ACB and in Group ACB than in Group ITD at postoperative 4 hours (P = 0.018 and P = 0.041, respectively); in Group ITD+ACB than in Group ITD and Group ACB at postoperative 8 hours (P = 0.005 and P = 0.011, respectively); and in Group ITD+ACB compared to Group ITD at postoperative 12 hours (P = 0.005). The time to the first rescue analgesic was notably longer in Group ITD+ACB compared to Group ITD and Group ACB (P value < 0.05)and in Group ACB compared to Group ITD (P < 0.001). Side effects were similar in all 3 groups. Our trial had a relatively limited sample size and was conducted at a single center. Combined ITD and ACB were superior in TKA postoperative pain management and required decreased postoperative analgesia without significant side effects compared to ACB alone or ITD alone.