Analgesic Effect Of Dexmedrtomidine Combined With Local Anesthetics For Transverse Muscle Plane Block:a Meta-Analysis

Objective Transverse abdominal muscle plane block technology is widely used in anesthesia in general surgery,it has the advantages of enhancing the analgesic effect,prolonging the duration of postoperative analgesia,and reducing the use of postoperative opioids.However,due to the pharmacological characteristics of local anesthetics,the analgesic effect of local anesthetics alone in transverse abdominal muscle plane block is limited.Many scholars’ research results show that dexmedetomidine can be used as an adjuvant to local anesthetics,but its safety and effectiveness are evaluated differently.This study assessed the safety and efficacy of dexmedetomidine combined with local anaesthesia in transverse abdominis plane block based on statistical methods after the retrieval and inclusion of qualified randomized controlled trials to provide a reference for clinical application.Methods By searching Pub Med,EMBASE,Cochrane Library,web of science,MEDLINE,sinomed,CNKI,Wanfang Database and VIP Chinese network by computer,the retrieval time was from the establishment of the database to December2021.Keywords in Chinese included "dexmedetomidine,transverse abdominal muscle plane block and adjuvant",and the English search words have "dexmedetomidine,transverse abdominal block and nerve block".Two researchers independently searched,screened,and extracted data from the included literature according to the determined inclusion criteria.We used Review Manager 5.4provided by Cochrane Library to analyze the data,mainly including the resting VAS score of 6 hours,12 hours and 24 hours after the operation,the consumption of opioids within 24 hours after the procedure,the time required for the first analgesia,the duration of analgesia maintenance,the number of active pressing of the analgesic pump within 24 hours afte rthe operation,the period of sensory block and the rate of postoperative nausea and vomiting.In terms of the outcome index of opioid consumption,5 articles compared the use of morphine,2 articles compared the use of sufentanil,and one article compared the use of fentanyl.The extracted data were converted and finally expressed in morphine.Results A total of 20 works of literature and 1262 patients were included in this study.Patients receiving dexmedetomidine combined with local anesthetic (experimental group)had a better analgesic effect than those using local anesthetic alone(control group).The resting VAS score of the experimental group at 6 hours and 12 hours after operation was lower than that of the control group [MD=-1.20,95% CI(-1.49 ～-0.91),P < 0.00001],[MD =-0.95,95% CI(-1.21～-0.69),P < 0.00001],There was no significant difference in 24-hour resting VAS score between the experimental group and the control group [MD =-0.12,95% CI(-0.26～-0.02),P = 0.10].In this study,a total of 8 kind of literature compared the use of opioids 24 hours after the operation.The results showed that compared with the control group,the use of opioids in the experimental group was significantly reduced24 hours after operation [MD =-11.81 mg,95% CI(-13.88 ～-9.74mg),P < 0.00001].In terms of the use times of the analgesic pump in the experimental group within 24 hours after the operation,it was significantly reduced by about 4.9 times compared with the control group [MD =-4.9,95% CI(-6.94 ～-2.86),P < 0.00001].In terms of analgesia,the first analgesic time needed in the experimental group was longer than that in the control group [MD = 3.49 hours,95% CI(2.54 ～ 4.44),P < 0.00001].The duration of postoperative analgesia and sensory block in the experimental group were increased compared with the control group [MD = 2.35 hours,95% CI(2.07 ～2.64),P < 0.00001],[MD = 2.30 hours,95% CI(2.15 ～ 3.45),P < 0.00001].The results showed that there was no significant difference between the two groups [OR= 1.20,95% CI(0.74 ～ 1.93),P = 0.46].Conclusion This meta-analysis indicates that dexmedetomidine as an adjuvant adding to local anesthetics for transverse abdominal muscle plane block can not only effectively reduce the postoperative pain and reduce the use of postoperative opioids but also increase the analgesic duration and sensory block duration of nerve block and reduce the number of pressing analgesic pump after the operation,but it has no advantage in the incidence of postoperative nausea and vomiting.