The Safety And Efficacy Of Dexmetomidine Combined With Local Anesthetics In Orthopedic Nerves Block

Objective Nerve block technology is currently widely used in orthopedics,general surgery and other operations,and has the advantages of reducing the consumption of opioids and postoperative analgesia.The analgesic effect of using local anesthetic alone is limited.There are many clinical studies show that dexmedetomidine can be used as an adjuvant for local anesthesia.However,the evaluation results of its safety and effectiveness are inconsistent.Therefore,This study included eligible randomized controlled trial searches and analyzed the effectiveness and safety of dexmedetomidine combined with local anesthetics in nerve blocks based on a standardized statistical analysis under the PRISMA code.So as to provide reference for clinical practice.Method According to the established inclusion criteria,as of October 2019,we have searched the keywords in the database of PUBMED,MEDLINE,Web of Science,EMBASE,Cochrane Library,Cochrane Central Register of Controlled Trials and included all RCTs investigating the efficacy and safety of perineural dexmetomidine combined with local anesthetic compared with local anesthetics alone.Statistical methods were used to evaluate the duration of analgesia,opioid consumption,the number of patients with bradycardia and hypotension.Results This meta-analysis included 21 randomized controlled trials,a total of 1402 patients,who received dexmedetomidine combined with peripheral injection of local anesthetic to obtain longer analgesia duration(MD=330.94 minutes,about 5.5 hours;95%confidence interval:250.58 to 411.30 minutes;I2=98%;P<0.01;evidence quality:medium).The duration of sensory block was prolonged(MD=267.98 minutes,95%confidence interval:241.72 to 294.24 minutes;I 2=99%;P<0.01).The duration of motor block was also prolonged(MD=259.55 minutes,95%confidence interval 187.39 to 331.71 minutes;I 2=100%;P=0).The onset time of sensory nerve block was about 3.9 minutes(MD=-3.90 minutes;95%confidence interval was-5.29 to-2.52 minutes;I 2=97%;P<0.01).The onset time of motor block was also shortened(MD=-4.16 minutes;95%confidence interval was-5.39 to-2.92 minutes;I 2=96%;P<0.01).The consumption of opioids was reduced by 17.54 Mg(MD=-17.54;95%confidence interval was-28.24 to-6.84 mg;I 2=88%;P<0.01).Ramsay Sedation score(MD=0.66;95%confidence interval is-0.17 to 1.49;I 2=98%;P<0.01).The most serious dexmedetomidine related adverse reaction was the occurrence of bradycardia during operation(RR=5.27;95%confidence interval is 2.36 to 11.79;I 2=1%).There was little heterogeneity between studies reporting bradycardia events.Conclusion According to this meta-analysis,dexmedetomidine combined local anesthetic can prolong the duration of analgesia by about 5.5 hours,the duration of sensory block is extended by about 4.5 hours,the duration of motion block is extended by about 4.3 hours,and the effect required by sensory block The time was shortened by about 3.9 minutes,the onset time required for motor block was shortened by about 4.16 minutes,and the consumption of opioids was reduced by 17.54 mg within 24 hours after surgery,Ramsay sedation score low.However,there is a risk of bradycardia during the operation,and the risk of positive dose correlation is increased.The preliminary evidence suggests that there is no significant difference in the duration of analgesia by peripheral or intravenous injection of dexmedetomidine combined with local anesthetics,but this conclusion still needs to be further demonstrated by more large sample prospective randomized controlled clinical trials.