Dexmedetomidine plus bupivacaine versus bupivacaine alone in peridural infusion for control of postsurgical pain [Dexmedetomidina más bupivacaúna frente a bupivacaúna sola en infusión peridural para el control del dolor postquirúrgico]

Abstract

Introduction: Postsurgical pain is the main cause of acute pain in hospital settings. Selective &?????;-2 adrenergic agonists such as clonidine and dexmedetomidine administered via peridural infusion have been evaluated in postsurgical pain control, since they act on brain stem, spinal and peripheral receptors, modulating the nociceptive input. In this context, clonidine is the most studied drug, but little information exists with dexmedetomidine. Objective: To evaluate the efficacy of the add-on use of dexmedetomidine in peridural anesthesia, as a strategy aimed to diminish postsurgical pain. Methods: An open-label trial was designed to compare bupivacaine via 24-h peridural infusion (n = 15) versus the combination of bupivacaine and dexmedetomidine (Bupi/Dexme, n = 21) in women who underwent abdominal hysterectomy. The main study outcome was the magnitude of postsurgical pain (as reflected in a visual analog scale) and the need for rescue analgesia during 24 h of peridural infusion after surgery. We also evaluated the impact on heart rate(HR) and mean arterial pressure (MAP) during the same period. Results: We observed significant differences with respect to the subjective patients' pain scoring, from the first 4 h after infusion initiation, favoring Bupi/ Dexme group (p < 0.05). Moreover, time to rescue analgesia and mean cumulative analgesic load were lower in Bupi/Dexme group, as compared with bupivacaine alone (in both, p < 0.05). HR and MAP were significantly lower in the Bupi/Dexme group at 4, 8, 12 and 24 h after infusion initiation, but without important hemodynamic repercussion. Conclusions: The administration of bupivacaine and dexmedetomidine via peridural infusion is a useful strategy in management of postsurgical pain, without clinically meaningful hemodynamic impact