Analgesic efficacy of perineural dexmedetomidine with bupivacaine in adductor canal block for post total knee arthroplasty: a randomized controlled trial

Abstract

Objectives: The primary objective was to study the anaนาlgesic efficacy of perineural dexmedetomidine with bupivacaine in adductor canal block (ACB) in patients undergoing total knee arthroplasty (TKA) and the secondary objectives were to investigate the ambulation ability and the side effects.

Materials and Methods: Sixty patients aged 18-85 years, ASA status I-III underwent primary, unilateral TKA under spinal anesthesia. They were randomized into 2 groups; Group C received 20 ml 0.25% bupivacaine and Group D received 20 ml 0.25% bupivacaine plus 0.5 mcg/kg dexmedetomidine for ACB. The primary outcome was 1st rescue analgesic duration. 24-hour morphine consumption, postoperative pain score, quadriceps motor strength, Timed up & Go (TUG) test, patient satisfaction, and adverse outcomes were also assessed.

Results: The patient demographic and intraoperative data were comparable in both groups. The time to median 1st rescue dose of morphine (minutes) (group C: 196 [95% CI: 89, 363], group B: 184 [95% CI: 105, 267], and P-value = 0.112), 24-hour morphine consumption (mg) (group C: 6.5 [Q1, Q3: 4, 10], group D: 9 [Q1, Q3: 3.25, 14.50] and P-value = 0.245) and postoperative pain score (at rest and on movement (NRS score 0-10) (P-value = 0.829 and 0.888, respectively) showed no significant differences between groups. There were no significant differences in TUG test (minutes) and quadriceps motor strength (torques) at preoperative and 48-hour postoperative between groups. Adverse events and patient satisfaction also showed no statistical differences between groups.

Conclusions: The addition dexmedetomidine to bupivacaine was not better than single-shot ACB regarding postoperative analgesia and ambulation ability following TKA. However, there were high rates of patient satisfaction with low adverse event rates in both groups.