Effects of preanesthetic administration of midazolam, clonidine, or dexmedetomidine on postoperative pain and anxiety in children

Background: A growing interest in the possible influences of pre- and postoperative anxiety and pain scores as outcomes of surgical treatment and benefits of anxiety or pain-reducing interventions has emerged. The aim of this study was to evaluate the influence of three different premedication regimens on postoperative pain and anxiety in children. Methods: A prospective, randomized, open-label clinical trial enrolled 60 schoolchildren. They were randomized for premedication with oral midazolam 0.5 mg.kg(-1), oral clonidine 4 mu g.kg(-1), or transmucosal dexmedetomidine (DEX) 1 mu g.kg(-1), submitted to a pre- and postoperative evaluation of anxiety with the State-Trait Anxiety Inventory for Children and asked to report any pain in verbal and visual analog scales. We also evaluated secondary outcomes such as parents' anxiety, sedation, separation from parents, adverse effects and hemodynamic status. Results: Dexmedetomidine and clonidine were related to lower scores of pain than midazolam. alpha(2)-agonists produced lower scores of peroperative mean arterial pressure and heart rate than midazolam. Both groups had similar levels of postoperative state-anxiety in children. There was no difference in preanesthesia levels of sedation and response to separation from parents between groups. Conclusions: These findings indicate that children receiving clonidine or DEX preoperatively have similar levels of anxiety and sedation postoperatively as those receiving midazolam. However, children given alpha(2)-agonists had less perioperative sympathetic stimulation and less postoperative pain than those given midazolam.