Stachnik Joan
Department of Pharmacy Practice, College of Pharmacy, University of Illinois Medical Center at Chicago, Chicago, IL, USA.
Am J Health Syst Pharm. 2006 Apr 1;63(7):623-34. doi: 10.2146/ajhp050460.
The pharmacology, bioavailability and pharmacokinetics, indications, clinical efficacy, adverse effects and toxicities, and dosage and administration of the inhaled anesthetics are reviewed.
The inhaled anesthetics include desflurane, enflurane, halothane, isoflurane, and sevoflurane and are thought to enhance inhibitory postsynaptic channel activity and inhibit excitatory synaptic activity. The mechanism of action of inhaled anesthetics has not been completely defined. A number of factors can influence the pharmacokinetics of inhaled anesthetics, including solubility in blood, cardiac output, tissue equilibration, extent of tissue perfusion, metabolism, and age. All of the available inhaled anesthetics are effective for inducing or maintaining anesthesia or both. Most clinical trials of inhaled anesthetics have evaluated differences in induction and emergence from anesthesia by comparing (1) times to loss of reflex, extubation, and response to verbal commands; orientation to time and place; and ability to sit up without assistance, (2) need for post-surgical analgesia, and (3) time to discharge as measures of efficacy. Adverse effects and toxicities of the inhaled anesthetics include nephrotoxicity, hepatotoxicity, cardiac arrhythmias, neurotoxicity, postoperative nausea and vomiting, respiratory depression and irritation, malignant hyperthermia, and postanesthesia agitation. Safety issues surrounding these gases include occupational exposure and intraoperative fires within the delivery systems used with inhaled anesthetics. Drugs used for anesthesia during surgery can account for 5-13% of a hospital's drug budget.
The inhaled anesthetics have been shown to be both safe and effective in inducing and maintaining anesthesia. These agents differ in potency, adverse-effect profile, and cost. Newer anesthetic gases, such as sevoflurane and desflurane, appear to have more favorable physico-chemical properties. These factors, as well as patient characteristics and duration and type of procedure, must be considered when selecting an inhaled anesthetic.
对吸入麻醉药的药理学、生物利用度和药代动力学、适应证、临床疗效、不良反应和毒性以及剂量与用法进行综述。
吸入麻醉药包括地氟烷、恩氟烷、氟烷、异氟烷和七氟烷，被认为可增强抑制性突触后通道活性并抑制兴奋性突触活性。吸入麻醉药的作用机制尚未完全明确。许多因素可影响吸入麻醉药的药代动力学，包括在血液中的溶解度、心输出量、组织平衡、组织灌注程度、代谢和年龄。所有现有的吸入麻醉药在诱导或维持麻醉或两者兼而有之方面均有效。吸入麻醉药的大多数临床试验通过比较以下方面评估麻醉诱导和苏醒的差异：（1）反射消失、拔管及对言语指令反应的时间；对时间和地点的定向能力；以及无需辅助坐起的能力，（2）术后镇痛的需求，以及（3）出院时间作为疗效指标。吸入麻醉药的不良反应和毒性包括肾毒性、肝毒性、心律失常、神经毒性、术后恶心和呕吐、呼吸抑制和刺激、恶性高热以及麻醉后躁动。围绕这些气体的安全问题包括职业暴露以及吸入麻醉药使用的输送系统内的术中火灾。手术期间用于麻醉的药物可占医院药品预算的5 - 13%。
吸入麻醉药已被证明在诱导和维持麻醉方面既安全又有效。这些药物在效能、不良反应谱和成本方面存在差异。较新的麻醉气体，如七氟烷和地氟烷，似乎具有更有利的物理化学性质。在选择吸入麻醉药时，必须考虑这些因素以及患者特征、手术持续时间和类型。
