Dexmedetomidine as an adjunct for caudal anesthesia and analgesia in children.

INTRODUCTION: The aim of this review was to evaluate the current evidence regarding the use of dexmedetomidine as an adjuvant to local anesthetic agents (LAA) for caudal blockade anesthesia and analgesia in children. EVIDENCE ACQUISITION: A literature search was performed of the Medline, Embase, and CINAHL databases using the keywords "dexmedetomidine" and "caudal". We included all studies that used caudal dexmedetomidine as an adjuvant to a LAA in children, excluding case reports, reviews, expert opinions, and animal studies. EVIDENCE SYNTHESIS: Twenty-one publications met the inclusion criteria and included 1590 children. Fourteen compared the efficacy of adding dexmedetomidine to a LAA alone and seven compared dexmedetomidine to other adjuvants in combination with a LAA. The duration of postoperative analgesia was significantly longer in patients receiving a caudal epidural block with a LAA plus dexmedetomidine when compared to a LAA alone. Only one study demonstrated improved analgesia with a dose of dexmedetomidine ≥1 µg/kg. Dexmedetomidine provided longer postoperative analgesia than fentanyl and morphine, while the quality of postoperative analgesia was similar to dexamethasone or clonidine. Although higher sedation scores were associated with caudal dexmedetomidine in the majority of the trials, postoperative behavior scores were improved in these children. There were no reports of respiratory depression. Significant hemodynamic effects were uncommon, and occurred most commonly in patients receiving a higher dose of caudal dexmedetomidine (2 µg.kg-1). CONCLUSIONS: There is sufficient evidence to recommend the addition of caudal dexmedetomidine to the LAA in patients undergoing lower extremity and infra-umbilical surgical procedures.