Dexmedetomidine對(duì)於止血帶所引起術(shù)中高血壓的療效及藥理機(jī)轉(zhuǎn)之探討課件

1、dexmedetomidine對(duì)於止血帶所引起術(shù)中高血壓的療效及藥理機(jī)轉(zhuǎn)之探討1臨床試驗(yàn)計(jì)劃臨床試驗(yàn)計(jì)劃: :dexmedetomidinedexmedetomidine對(duì)於止血帶所引起術(shù)中高對(duì)於止血帶所引起術(shù)中高血壓的療效及藥理機(jī)轉(zhuǎn)之探討血壓的療效及藥理機(jī)轉(zhuǎn)之探討 presenter:勞萱之醫(yī)師correspondence: 黃俊仁主任dexmedetomidine對(duì)於止血帶所引起術(shù)中高血壓的療效及藥理機(jī)轉(zhuǎn)之探討2part :introduction of dexmedetomidinedexmedetomidine對(duì)於止血帶所引起術(shù)中高血壓的療效及藥理機(jī)轉(zhuǎn)之探討3medetomidine

2、動(dòng)物鎮(zhèn)靜麻醉 ketamine (k他命）和 midazolam 混合 medetomidine medetomidine混合dextro-medetomidine levo-medetomidinedexmedetomidine對(duì)於止血帶所引起術(shù)中高血壓的療效及藥理機(jī)轉(zhuǎn)之探討4dexmedetomidine alpha-2 agonist 1999 美國fda 核準(zhǔn)使用drug2/1 selectivitydexmedetomidine1600medetomidine1200clonidine200dyck, shafer. aneasth pharm review. 1993dexmede

3、tomidine對(duì)於止血帶所引起術(shù)中高血壓的療效及藥理機(jī)轉(zhuǎn)之探討5dexmedetomidine (precedex)適應(yīng)癥：適應(yīng)癥：適用於在加護(hù)病房中，插管且接受呼吸器治療的病患鎮(zhèn)靜用。precedex應(yīng)該以連續(xù)輸注的方式給予，連續(xù)輸注以24小時(shí)為限。dexmedetomidine對(duì)於止血帶所引起術(shù)中高血壓的療效及藥理機(jī)轉(zhuǎn)之探討6自主神經(jīng)系統(tǒng)副交感交感新腎上腺素新腎上腺素乙醯膽鹼腎上腺素接受器腎上腺素接受器dexmedetomidine對(duì)於止血帶所引起術(shù)中高血壓的療效及藥理機(jī)轉(zhuǎn)之探討7腎上腺素接受器腎上腺素接受器adrenergic receptors平滑肌節(jié)前pre-synaptic氣管平

4、滑肌心臟擴(kuò)張心跳心搏量收縮抑制抑制新腎上腺素新腎上腺素ne 分泌分泌dexmedetomidine對(duì)於止血帶所引起術(shù)中高血壓的療效及藥理機(jī)轉(zhuǎn)之探討8a a2腎上腺素接受器腎上腺素接受器負(fù)回饋 regulate release of neurotransmitters control epinephrine, norepinephrine release modulate sympathetic response “negative feedback loop”dexmedetomidine對(duì)於止血帶所引起術(shù)中高血壓的療效及藥理機(jī)轉(zhuǎn)之探討9dexmedetomidine作用機(jī)轉(zhuǎn)dexmedeto

5、midine對(duì)於止血帶所引起術(shù)中高血壓的療效及藥理機(jī)轉(zhuǎn)之探討10dexmedetomidine作用部位 作用部位 brain (locus ceruleus)第第4腦室底上角之色素隆凸腦室底上角之色素隆凸 spinal cord 脊髓交感神經(jīng) 中樞神經(jīng)之作用 sedation 鎮(zhèn)靜 anxiolysis 抗焦慮 analgesia 止痛交感神經(jīng)之作用 sympathetic activity bp, hrdexmedetomidinespinal cordlocusceruleusfourthventricleponscerebrumcerebellumdexmedetomidine對(duì)於止血帶

6、所引起術(shù)中高血壓的療效及藥理機(jī)轉(zhuǎn)之探討11a a2-receptor subtypes2c2a2aa2a利尿止痛鎮(zhèn)靜心跳抑制顫抖血管dexmedetomidine對(duì)於止血帶所引起術(shù)中高血壓的療效及藥理機(jī)轉(zhuǎn)之探討12mechanism for 2-induced sedation/ hypnosis in the rat locus coeruleusdexmedetomidine對(duì)於止血帶所引起術(shù)中高血壓的療效及藥理機(jī)轉(zhuǎn)之探討13dexmedetomidine對(duì)於止血帶所引起術(shù)中高血壓的療效及藥理機(jī)轉(zhuǎn)之探討14dexmedetomidine: side effects bradycardia

7、hypotension transient hypertension dry mouth limited amnestic effect excessive sedation reduction in cbf/cmro2 in animal modeldexmedetomidine對(duì)於止血帶所引起術(shù)中高血壓的療效及藥理機(jī)轉(zhuǎn)之探討15dexmedetomidine 的使用 (adult) heart block 心房心室傳導(dǎo)阻滯的病患，要小心使用 administer loading dose slowly 第1個(gè)劑量要慢慢給 transient vasoconstriction mediate

8、d by 2b-adrenoceptors will bp loading : 1 mcg/kg over 10 min maintenance : 0.2 to 0.7 mcg/kg/hr onset: 5 -10 min reduced effect: 30 min duration: 2 hourdexmedetomidine對(duì)於止血帶所引起術(shù)中高血壓的療效及藥理機(jī)轉(zhuǎn)之探討16tournique induced hypertension incidence: 30% tourniquet time 60 min associated with severe pain and augmen

9、ted sympathetic outflow difficult treatment unknown mechanism dexmedetomidine對(duì)於止血帶所引起術(shù)中高血壓的療效及藥理機(jī)轉(zhuǎn)之探討17previous study data ketamine ( satsumae et al. a&a, 2001) clonidine ( zalunardo et al. a&a, 2002) dextromethrophan ( yamashita et al. a&a, 2004) stellate ganglion blockade ( arai et al.

10、 acta anesthesiol scand, 2004) dexmedetomidine?dexmedetomidine對(duì)於止血帶所引起術(shù)中高血壓的療效及藥理機(jī)轉(zhuǎn)之探討18exclusion and inclusion crietria exclusion criteria貧血 (hct 20)肥胖 (bmi 40)肝或腎功能異常者心律不整,av block,或是心臟鬱血性衰竭對(duì)dexmedetomidine或其他2 agonist過敏者預(yù)期下肢止血帶使用會(huì)超過150分鐘或低於60分鐘 inclusion criteriaasa i-ii20 至75 歲預(yù)期接受骨科下肢常規(guī)手術(shù)而會(huì)打止血帶

11、超過60分鐘者不論半身或全身麻醉 dexmedetomidine對(duì)於止血帶所引起術(shù)中高血壓的療效及藥理機(jī)轉(zhuǎn)之探討19grouping control group dexmedetomidine (continuous infusion) loading:(0.8 g/kg) continuous infusion rate:(0.4 g/kg/h) dexmedetomidine (single dose) 1ug/kg for over 10 mins dexmedetomidine (continuous infusion) loading:(0.5 g/kg) continuous in

12、fusion rate:(0.4 g/kg/h) dexmedetomidine對(duì)於止血帶所引起術(shù)中高血壓的療效及藥理機(jī)轉(zhuǎn)之探討20anesthetic standard procedure general anesthesia pre-op : iv 1.5-2 mg midazolam induction medication: fentanyl 2 ug/ml, propofol 2mg/kg, and recuronium 0.6 mg/kg. maintenance medication: sevoflurane which concentration is adjusted to

13、keep bis 40-45. tof rescue (bp) : perdipine 1ml/ 5min combined spinal-epidural anesthesia pre-op : iv 1.5-2 mg midazolam spinal bupivaccaine dosage: 12-15 mg epidural dosage: 0.25% bupivacaine with continuous rate of 4-8 ml/h. level 15 min rescue: fentanyl 1ml/15mndexmedetomidine對(duì)於止血帶所引起術(shù)中高血壓的療效及藥理機(jī)轉(zhuǎn)之探討21monitoring 血液 ne & epi 濃度(2 times x 10 ml)post-induction (1 mac) & tourniquet