1、p镇痛p镇静p精准麻醉p可视化操作p刺激交感系统p增加心肌氧耗p延缓患者自主活动恢复p改变免疫系统p诱发慢性疼痛 2 2 Agonists:Chemical StructuresAgonists:Chemical StructuresNNHNClClDexmedetomidineClonidineCH3CH3NNCH3Hq高效、高选择性和特异性高效、高选择性和特异性的的 2 2受体激动剂受体激动剂q抑制交感神经活性抑制交感神经活性q镇静、催眠和麻醉作用镇静、催眠和麻醉作用q镇痛作用镇痛作用p蓝斑是大脑内负责调解觉醒与睡眠的关键部位p蓝斑是下行延髓-脊髓去甲肾上腺素能通路的起源，其在伤害性神经递
2、质的调控中起重要作用l2-受体激动剂作用于去甲肾上腺素能神经元突触前膜2-受体，减少去甲肾上腺素释放，从而产生镇静作用。2 2 激动剂激动剂初级传入纤维初级传入纤维皮层皮层丘脑丘脑中脑中脑延髓延髓p镇痛作用的位点可能位于脊髓，脊髓中存在肾上腺素能下行抑制系统。2-受体激动剂激动脊髓背角2-受体，产生镇痛作用。p作用于中枢，抑制交感神经发放冲动，从而使血压下降、心率减慢。p作用于外周血管平滑肌的2B-受体，可使血管收缩，出现一过性的血压升高，小剂量缓慢注射可避免这一现象的出现。p呼吸系统 无明显呼吸抑制p肾脏功能 利尿作用p内分泌系统 减少去甲肾上腺素、胰岛 素、皮质醇的释放。pDEX作为关节腔
3、的注射用药在术后镇痛中的应用pDEX作为神经阻滞的复合用药在术后镇痛中的应用pDEX作为阿片类药物的辅助用药术后镇痛中的应用Sixty patients，double-blind placebo controlled.control group:i.v.20ml saline and intra-articular 20ml saline the intra-articular group:i.v.20ml saline and intra-articular 20ml saline+dexmedetomidine1ug/kg the i.v.group:i.v.20ml saline+dex
4、medetomidine1ug/kg and intra-articular 20ml saline.significant reduction in pain scores for 6 h after operation in the intra-articular group but only for 1 h in the i.v.group.The time to first postoperative analgesic request was longer in the intra-articular group 312.0(SD 120.7)min compared with th
5、e control group 71.0(50.1)min and the i.v.group 102.1(54.4)min(P0.001).total diclofenac requirement was significantly lower in the intra-articular group 90.0(46.2)mg than in the control group 165.0(52.2)mg and in the i.v.group 129.3(54.3)mg(P4.Time of first analgesia request and total rescue analges
6、ic used in 24 hours were calculated.RESULTS:Time for requirement of first postoperative rescue analgesia in Group A was 380.61 22.973 min,in Group B was 326.82 17.131 min and in Group C was 244.09 20.096 minutes.Total rescue analgesia requirement was less in Group A(1.394 0.496)compared to Group B(1
7、.758 0.435)and Group C(2.546 0.546).Group A had higher mean VAS score at 6(th)and 24(th)postoperative hours.No side effects found among the groups.CONCLUSION:intra-articular ropivacaine gives better postoperative pain relief increased time of first analgesic request decreased need of total postopera
8、tive analgesia compared to fentanyl and dexmedetomidine.There was also evidence of a decrease in pain intensity at 24 h;the weighted mean difference was-0.7 cm(-1.2 to-0.1)on a 10-cm visual analog scale with clonidine and-0.6 cm(-0.9 to-0.2)with dexmedetomidine.There was also evidence of a decrease
9、in pain intensity at 12 h;the weighted mean difference was-1.5 cm(-2.1 to-1.0)on a 10-cm visual analog scale with clonidine and-1.4 cm(-2.7 to-0.2)with dexmedetomidine at 1h.The incidence of early nausea was decreased with both(number needed to treat,approximately nine).Clonidine increased the risk
10、of intraoperative(number needed to harm,approximately nine)andpostoperative hypotension(number needed to harm,20).Dexmedetomidine increased the risk of postoperative bradycardia(number needed to harm,three).R CONCLUSIONS:Perioperative systemic 2 agonists decrease postoperative opioid consumption,pai
11、n intensity,and nausea.Recovery times are not prolonged.Common adverse effects are bradycardia and arterial hypotension.The impact of 2 agonists on chronic pain or hyperalgesia remains unclear because valid data are lacking.METHODS:double-blinded,randomized,controlled study,100 women undergoing abdo
12、minal total hysterectomy were allocated Group M：receive either morphine 1 mg/ml Group D:morphine 1 mg/ml plus dexmedetomidine 5 ug/ml postoperative i.v.PCA,which was programmed to deliver 1 ml per demand with a 5 min lockout interval and no background infusion.Cumulative PCA requirementspain intensi
13、tiescardiovascular and respiratory variables PCA-related adverse events were recorded for 24 h after operation.Compared with Group M,patients in Group D required 29%less morphine during the 0-24 h postoperative period and reported significantly lower pain levels from the second postoperative hour on
14、wards and throughout the study.decreases in heart rate from presurgery baseline at 1,2,and 4 h after operation were significantly greater in Group D(by a range of 5-7 beats min(-1)respectively).decreases in mean blood pressure from presurgery baseline at 1,2,and 4 h after operation were significantl
15、y greater in Group D(by a range of 10-13%,respectively).Whereas levels of sedation were similar between the groups at each observational time point,The 4-24 h incidence of nausea was significantly lower in Group D(34%vs 56.3%,P0.05).There was no bradycardia,hypotension,oversedation,or respiratory de
16、pressionCONCLUSIONS:The addition of dexmedetomidine to i.v.PCA morphine resulted in superior analgesia significant morphine sparing less morphine-induced nausea devoid of additional sedation and untoward haemodynamic changes.PATIENTS:One hundred and twenty parturients(American Society of Anesthesiol
17、ogists class 1 or 2)scheduled for elective caesarean delivery under spinal anaesthesia randomly allocated into three groups(n=40 each).INTERVENTIONS:Group 1:physiological saline bolus after delivery and sufentanil PCA,Group 2:dexmedetomidine bolus(0.5gkg)after delivery and sufentanil PCAGroup 3:dexm
18、edetomidine bolus(0.5gkg)after delivery and sufentanil with dexmedetomidine PCA(background infusion of 0.045gkgh with a bolus of 0.07gkg).PTh and PTTh were significantly increased 1h after drug administration in groups 2(1.590.45,2.570.46mA)and 3(1.740.37,2.560.48mA)compared with group 1(1.490.49,2.
19、420.62mA)(P0.05).Sufentanil consumption in group 3 was 43.919.2g,significantly lower than in group 1(54.523.9g)and group 2(56.320.6g)(P0.05).Compared with group 3,VAS was increased at 4,8 and 24h after surgery in groups 1 and 2(P0.05);there was no difference between groups 1 and 2*Proc(Bayl Univ Med
20、 Cent).2019 Jan;27(1):3-10.METHODS:Thirty-eight thoracotomy patients were administered dexmedetomidine intraoperatively and overnight postoperatively and then randomized to receive placebo or dexmedetomidine titrated from 0.1 to 0.5 gkgh(-1)the day following surgery for up to 24 hours on a telemetry
21、 floor.Opioids via a patient-controlled analgesia pump were available for both groups,and vital signs including transcutaneous carbon dioxide,pulse oximetry,respiratory rate,and pain and sedation scores were monitored.The dexmedetomidine group used 41%less opioids but achieved pain scores equal to t
22、hose of the placebo group.The mean respiratory rate and oxygen saturation were similar in the two groups.Mild hypercarbia occurred in both groups,but periods of significant respiratory depression were noted only in the placebo group.Significant hypotension was noted in one patient in the dexmedetomi
23、dine group in conjunction with concomitant administration of a beta-blocker agent.The placebo group reported a higher number of opioid-related adverse events.结果4*Evaluation of dexmedetomidine and postoperative pain management in patients with adolescent idiopathic scoliosis:conclusions based on a re
24、trospective study at a tertiary pediatric hospital.Jones JS1,Cotugno RE,Singhal NR,Soares N,Semenova J,Nebar S,Parke EJ,Shrader MW,Hotz J.Pediatr Crit Care Med.2019 Jul;15(6):e247-52.结果4*DESIGN:This was a retrospective chart review.Patients were separated into two groups:those that received opioid v
25、ia patient-controlled analgesia pain therapy alone those that received opioid via patient-controlled analgesia pain therapy with dexmedetomidine.PATIENTS:One hundred sixty-three children with adolescent idiopathic scoliosis.*MEASUREMENTS AND MAIN RESULTS:Measurements included patient demographics,Am
26、erican Society of Anesthesiologists Physical Status Classification System,levels of spinal fusion,length of hospital stay,complications,numeric pain scores,opioid requirement,elastomeric pain pump use,length of time until ambulation,adverse effects,and naloxone use.Data were collected through the fi
27、rst 72 hours of the perioperative period.One hundred six patients received opioids via patient-controlled analgesia therapy with dexmedetomidine and 57 received opioids via patient-controlled analgesia alone.Within the groups,there were 46 patients who received local anesthetic infusions via elastom
28、eric pumps in the patient-controlled analgesia with dexmedetomidine group and 16 patients had pumps in the patient-controlled analgesia-alone group.There was no overall difference in postoperative use of morphine(or equivalents)between the two groups.However,the use of elastomeric pain pumps demonst
29、rated a statistically significant decrease in mean overall opioid consumption(42.6 mg vs 63.1 mg,p 0.001).*CONCLUSIONS:There was no difference in opioid use related to dexmedetomidine on any postoperative day.The only variable showing a significant opioid sparing effect was the use of local anesthet
30、ic infusions via elastomeric pumps.Using continuous local anesthetic infusions instead of dexmedetomidine could eliminate the need for ICU admission,require shorter hospital stays,and reduce costs while still providing safe and effective pain control.*Comparison of patient-controlled analgesia with
31、and without dexmedetomidine following spine surgery in children.Sadhasivam S1,Boat A,Mahmoud M.J Clin Anesth.2009 Nov;21(7):493-501*DESIGN:Retrospective comparison.SETTING:University-affiliated childrens hospital.MEASUREMENTS:The medical charts of 131 children with idiopathic scoliosis(IS)and NMS wh
32、o had major spine surgery were reviewed.Out of 131,postoperatively 94 children received PCA with morphine alone(PCA group)and the remaining 37 children received PCA morphine and dexmedetomidine infusion at 0.4 mcg/kg/hour for 24 hours(PCA+Dex group).Preoperative,intraoperative,and postoperative morp
33、hine use data were collected.*MAIN RESULTS:Intraoperative use of morphine was similar in children with IS and NMS.However,patients with IS used more morphine than patients with NMS on the first,second and third postoperative days in both groups.In children with IS,use of morphine on the second posto
34、perative day was significantly higher in the PCA+Dex group(73 mg 50.5,110.5)than the PCA alone group(54 mg 36,69,P=0.03).The overall frequency of all perioperative complications was more in the PCA alone group(40%vs.32%)than the PCA+Dex group.*CONCLUSION:Postoperative 24-hour dexmedetomidine infusio
35、n as an adjunct to PCA with opioids might have a morphine-sparing effect as evidenced by the increase in morphine use on postoperative day 2 after the dexmedetomidine infusion was stopped.DEX具有的镇静、镇痛、抗焦虑、抗交感兴奋作用且对呼吸系统的抑制作用轻微，其在围麻醉期的应用越来越广。关注DEX的临床优越性的同时，其尚未明确的作用机制及安全剂量范围仍需探索，有关副作用仍需提防，以便为临床应用提供更好的基础。展 望
