吸入麻醉.ppt

第七章 吸入麻醉 Inhalational Anesthesia 一、概述 （introduction） 1.概念(concept) 2.特点(characteristic) 可控性好 不留任何后遗症 二、吸入麻醉药的吸收、分布与消除 Uptake, distribution and elimination  of inhalational anesthetics 1、吸收与分布Uptake and distribution 作用部位:大脑 central nerve system PA PB PBr 动态平衡 dynamic equilibrium 吸收与分布影响因素： 吸入浓度 inspired concentration 分钟通气量 minute volume 血/气分配系数 blood/gas partition coefficient 每分钟肺灌流量 perfusion of pulmonary 三、吸入麻醉药的临床评价 Clinical evaluation of inhalational anesthetics 1.可控性 controllable ● 与血/气分配系数有关 associated with blood/gas partition coefficient 2. 麻醉强度 anesthetic potency ● 与油/气分配系数有关 associated with oil/gas partition coefficient ● MAC(minimal alveolar concentration) MAC is minimal alveolar concentration of an inhalational anesthetic at 1 atmosphere absolute that prevents movements of 50% of the population to a standard stimulus. 3. 对心血管的影响 Effects on Cardiovascular system ● 心肌抑制 depression of myocardial contractility ●增加心肌对儿茶酚胺的敏感性：氟烷 Increased myocardial excitability Arrhythmias are common during halothane Increased circulating catecholamines 5.对运动终板的影响 Effects on neuromuscular junction ●肌松作用，增强肌松剂的肌松作用 Skeletal muscle relaxation and potentiates non-depolarizing relaxants. ●安氟醚肌松作用最强 Skeletal muscle relaxation of enflurane is the greatest in all inhalational anesthetic . ●氟烷对子宫平滑肌松弛作用最强,增加产后出血可能 Hatholane relaxes uterine muscle and may cause postpartum hemorrhage.  ●增加颅内压，异氟醚影响最小 increase ICP, and this action of isoflurane is the lowest in all volatiles. ●抑制EEG，安氟醚可引起痉挛性EEG改变 Dose-dependent depression of EEG activity, at moderate to high concentration (more than 3%), enflurane produces epileptiform paroxysmal spike activity. 7.理想吸入麻醉药的特点 Properties of the ideal inhalational anesthetic Pleasant odour, non-irritant to respiratory depression low blood/solubility—rapid induction and recover from