Effects Of Caudal And IV Dexmedetomidine On Postoperative Analgesia In Patients Undergoing Anorectal Surgery

Background and objectivePostoperative pain is a common and unavoidable condition after surgery.If the pain problem cannot be effectively dealt with in a timely manner,the physical and mental health of patients will be seriously affected,and the quality of life and treatment effect of patients will decline.Hemorrhoids is a common clinical anorectal disease,and it can be cured with surgical treatment.However,the nerve around anorectum is rich,often resulting in acuteness postoperative pain,and delay the postoperative recovery.Caudal epidural block block is often used in pediatric lower abdominal surgery.However,there are few studies on anaesthesia for adult anorectal surgery,especially the influence of the two ways of using dexmedetomidine on analgesic effect of hemorrhoidectomy patients.Therefore,this study conducted a meta-analysis to comprehensively evaluate the clinical effect of caudal block,so as to provide a better clinical basis for the use of caudal block.Secondly,conduct a double-blind controlledtrial to explore the difference of the effects of caudal and IV dexmedetomidine in patients undergoing elective mixed hemorrhoidectomy and to optimize the intraoperative and postoperative management of patients.Materials and methodsFirst of all,this study adopted the meta-analysis method and followed the PRISMA guidelines.PubMed,Web of Science,Embase,Cochrane Library,WanFang,CNKI and VIP databases were searched for literatures from establishment to the November of 2018,and the results were limited to randomized controlled clinical trials(RCT)in Chinese and English.The control group was the patients with simple caudal block,and at least one group of the treatment group was treated with dexmedetomidine(DEX)as a local anesthetic adjutant for caudal block.Meta-analysis was performed with RevMan5.3 software.Secondly,a total of 105 patients who underwent selective hemorrhoidectomy were randomly divided into the caudal anesthesia group(group C),the caudal + IV DEX group(group D1)and the caudal + caudal DEX group(group D2).The duration of analgesia,total dosage of analgesia pump for 24 hours,postoperative pain score(VAS),intraoperative medication,vital signs,as well as recovery time,PACU residence time,vigilance/sedation score(OAA/S)and other recovery conditions were observed.SPSS 22.0 software was used for analysis.The quantitative data in line with the normal distribution were expressed as mean standard deviation((?)±s)or mean(95%confidence interval).If not normal distribution,the test of Kruskal-Wallis was used.Qualitative data is expressed in constituent ratios(percentages).P < 0.05 was considered statistically significant.ResultsA total of 22 clinical studies were included in the meta-analysis,9 in English and13 in Chinese.A total of 1240 patients,including 617 in the control group and 623 in the dexmedetomidine group.Meta-analysis results showed that compared with thecontrol group,the postoperative analgesia time was significantly longer in the DEX group,the onset time of caudal block was shortened,the motion block time was not prolonged,and the number of postoperative agitation was lower in the DEX group(P< 0.05).The recovery time of the experimental group was longer than that of the control group,but the difference was not statistically significant.A total of 105 patients were included in the randomized controlled trial,35 patients in each group,and the demographic was not statistically significant(P>0.05).Compared with group C,D1 and D2 group had a prolonged analgesia time and less analgesia pump total amount,less intraoperative dose,lower intraoperative blood pressure(P < 0.05),and caudal DEX group had longer analgesia time than IV EDX group,difference was statistically significant,but IV EDX group heart rate is lower,postoperative pain score,right at the 4 h caudal DEX group are lower than control group,but similar with IV EDX group,at 8 h caudal DEX group are lower than the other two groups,differences were statistically significant.There were no serious complications.ConclusionWhen dexmedetomidine was added to local anesthetics,compared with local anesthetics alone,caudal block showed short onset time,longer analgesia time,and lower incidence of postoperative agitation,without increasing the incidence of complications.When hemorrhoidectomy is performed,the two methods of dexmedetomidine for caudal block could reduce the dosage of analgesics and prolong the analgesia time,and the caudal dexmedetomidine method had the most longer analgesia time.