Dexmedetomidine as an adjunct to peripheral nerve blocks in pediatric patients

Background Combining local anesthetics with dexmedetomidine (DEX) for nerve blocks has been tested and confirmed as an alternative technique to strengthen analgesia in adults, but the evidence supported this proposal in pediatrics was not convincing enough. Thus, we intend to conduct a meta-analysis to make an appraisal of the effects of DEX as a local anesthetic adjuvant on peripheral nerve blocks in children. Methods The analysis has been registered on with the registration number CRD42021254029 on June 10th, 2021. PubMed, Ovid MEDLINE, Embase and Cochrane central register were searched for the randomized controlled trials (RCTs) that are relevant to child/pain/DEX or block up to April 30, 2021. Results Eight RCTs were included for data analysis. The pooled results showed a significantly reduced number of patients who required postoperative analgesics within DEX groups [odds ratio = 0.1, 95% confidence interval (CI) 0.03-0.32, P < 0.001]. And DEX significantly prolonged the duration of analgesia of local anesthetics in the meantime [standardized mean difference (SMD) = 4.93, 95% CI 3.02-6.83, P < 0.001]. Nevertheless, adding DEX as an adjunct to local anesthetics would significantly decrease heart rate (SMD = - 0.95, 95% CI - 1.45 to - 0.45, P < 0.001) and increase sedation score (SMD = 1.6, 95% CI 0.53-2.66, P = 0.003) simultaneously. Conclusions Adding DEX as an adjunct to peripheral nerve blocks can prolong analgesia until postoperative 8 hours in pediatric patients. However, the benefits should be weighed against the increasing risk of bradycardia and sedation in critical children.