Introduction: Local anaesthetic (LA) with highly selective alpha-2 agonist dexmedetomidine has not been evaluated in adductor canal block (ACB) for arthroscopic anterior cruciate ligament (ACL) reconstruction surgeries. The study evaluates postoperative analgesic effect of ropivacaine with adjuvant dexmedetomidine following postoperative ultrasound-guided ACB. Methods: 105 randomized subjects received ultrasound-guided ACB using 15 mL of 0.5% ropivacaine, with 0.5 µg kg−1 of dexmedetomidine administered perineurally (Group II), intravenously (Group III) or none (Group I). Primary outcome included 24 hours’ total morphine consumption postoperatively. Secondary outcomes included haemodynamics and adverse effects. Results: The postoperative total morphine consumption was significantly reduced till 4 hours in II 0.57 mg (0.98 (0–3)) (p = 0.011) and up to 6 hours in Group III 0.77 mg (1.00 (0–4)) (p = 0.004) compared to Group I. The postoperative total morphine consumption was comparable at 24 hours in Group III 3.57 mg (1.73 (0–8)) and Group II 3.34 mg (1.92 (07)) (p = 1.000). The visual analogue scale (VAS) scores were comparable in all the three groups at all the time intervals studied (p > 0.05). There were no adverse effects observed during the study. Conclusion: Use of perineural dexmedetomidine with LA for ACB in the postoperative period resulted in significant reduction in total morphine consumption in initial 4 hours as compared to 6 hours with intravenous (IV) dexmedetomidine.
D. Thapa, V. Ahuja, Khushboo Pandey
British Journal of Pain