Intravenous Versus Perineural Dexmedetomidine as Adjuvant in Adductor Canal Block for Total Knee Arthroplasty

Dexmedetomidine a highly selective α2 adrenergic agonist used effectively as a safe analgesic via different routes and mechanisms, including intravenous (i.v.), neuraxial and perineural routes. Dexmedetomidine has been used for prevent shivering but, the results of its efficacy is still controversy. No studies to date have investigated the best administration route of dexmedetomidine to dominantly prevent the occurrence of shivering after spinal anesthesia or associated with the least grade. This prospective, randomized, double blinded study was designed to investigate the best administrative route of dexmedetomidine firstly, as a preventive of neuraxial shivering and secondly as adjunctive analgesic. The incidence of post-spinal anesthesia shivering was the primary outcome. Perioperative hemodynamics, postoperative pain scores during rest and at 45-degree flexion of the knee, the analgesic duration, the first postoperative day analgesic consumption, the sedation score and early ambulation ability were the secondary outcomes.