全身麻醉的实施及并发症 Administration of general anesthesia & prophylaxis and treatment of complications 长江大学临床医学院 外科教研室

目的要求 掌握全麻的基本概念及基本要求。 熟悉全麻的诱导、维持和苏醒期的特点 及管理期注意事项。 了解全麻深浅的判断、临床常用的判断 麻醉深浅的监测指标。

第一节 全身麻醉的实施 Section one Administration of general anesthesia General anesthesia is a state of reversible loss of consciousness for the purpose of carrying out surgery. This is achieved by: Analgesia Amnesia Immobility Loss of consciousness Skeletal muscle relaxation

全身麻醉的基本特征 通过呼吸道吸入、静脉注射、肌肉注射或直肠 灌注等方式使麻醉药进入体内，利用麻醉药对 中枢神经系统产生的抑制作用，可逆地改变中 枢神经系统中的某些功能，从而达到神志消失、 （手术时）无痛的目的。 A controllable and reversible loss of consciousness induced by intoxication of the central nervous system. Lowered sensitivity to external stimuli (hyporeflexia), analgesia, unconsciousness, muscle relaxation, and amnesia are significant features of general anesthesia.

全身麻醉方法分类 吸入麻醉 Inhalational Anesthesia 静脉麻醉 Intravenous Anesthesia

一、麻醉诱导 Induction of anesthesia Definition Induction of anesthesia produces an unconscious patient with depressed reflexes who is entirely dependent on the anesthetist for maintenance of homeostatic mechanisms and safety.

诱导前的准备 preparation Preoperative evaluations Intravascular volume Intravenous (IV) access Preoperative medications Monitoring Resuscitation equipment & drugs

诱导方法 Induction techniques  IV induction  Inhalational induction  Intramuscular injection of ketamine or oral midazolam ： used in uncooperative patients or young children

二、全身麻醉的维持 Maintenance of anesthesia Definition Maintenance begins when the patient is sufficiently anesthetized to provide analgesia,unconsciousness, and muscle relaxation for surgery. Vigilance on the part of the anesthetist is required to maintain homeostasis (vital signs, acid-base balance, temperature, coagulation, and volume status) and regulate anesthetic depth.

麻醉维持方法 Maintenance of anesthesia volatile agents with minimal opioid In a nitrous oxide–opioid relaxant technique IV anesthesia ： uses the continuous infusion or repeated boluses of a short-acting hypnotic drug (e.g., propofol) with or without opioids (e.g., remifentanil) and a muscle relaxant. Combinations of the above methods are often used General anesthesia can be combined with a regional anesthetic technique

Guedel 乙醚麻醉分期 三、全身麻醉深度的判断 Judgement of anesthetic depth

MAC 的概念和意义 0.6MAC 意识消失 1MAC 50 ％患者不发生体动反应 MAC 95% 患者对切皮刺激无反应 1.7MAC 完全抑制插管时心血管反应

第二节：全身麻醉的并发症及其处理 prophylaxis and treatment of complications 一、反流与误吸 Regurgitation&Aspiration 原因 吞咽及咳嗽反射丧失、贲门松弛 胃内容物过多 并发症 呕吐与误吸 - 胃内容物反流 - 窒息 吸入性肺炎

一、反流与误吸 Regurgitation&Aspiration 处理 头低位引流 气管插管 肺部盥洗 抗菌消炎

二、上呼吸道梗阻 upper airway obstruction 原因 舌后坠、咽喉部分泌物、喉痉挛 预防 禁食和胃排空 处理 对症处理

三、下呼吸道梗阻 lower airway obstruction 原因 支气管痉挛、支气管分泌物阻塞 预防 对既往有呼吸道慢性炎症或支气管哮喘使的病人 应仔细了解其过去发病的情况 ; 避免应用可诱发 支气管痉挛的药物，阻断起到的反射 处理 对症处理

四、通气不足，二氧化碳潴留 原因 药物导致中枢性或外周的呼吸抑制，并辅助呼吸或控 制呼吸的分钟通气量不足 严重支气管痉挛导致肺泡通气量不足 预防 加强呼吸监测，保持足够的通气 处理 增加潮气量或提高呼吸频率 舒张支气管平滑肌，解除支气管痉挛，提高肺泡通气 量 必要时给予相应的拮抗药物

五、低氧血症 Hypoxia Etiologies Inadequate oxygen supply Hypoventilation Ventilation-perfusion inequalities Right-to-left cardiac shunt Reduction in oxygen-carrying capacity Leftward shift of the hemoglobin-oxygen dissociation curve

Treatment Manual ventilation with 100% oxygen should be begun to assess pulmonary compliance. The breathing circuit, ventilator, and anesthesia machine should be checked for leaks. Adequate oxygen delivery to the patient should be confirmed with an in-line oxygen analyzer. Others……

六、高血压 Hypertension 原因 高血压、甲亢等病人麻醉过浅 通气不足、二氧化碳潴留 疼痛、低氧血症与高碳酸血症 术中补液过多和升压应用不当 麻醉苏醒期拔管 处理 解除诱因，降压治疗 保证麻醉深度 必要时，小量、分次地给予血管扩张剂

七、低血压 Hypotension 原因 麻醉过深 失血过多并血容量补充不当 手术直接刺激迷走神经或牵拉内障反射 性地兴奋迷走神经 过敏反应，肾上腺皮质功能低下 心肌收缩功能障碍 处理 减浅麻醉，补充血容量 必要时停止手术刺激，或暂停手术

八、心律失常 arrhythmia 原因 麻醉深浅不当，手术刺激 高血压、低血压、二氧化碳潴留或缺氧 病人自身疾病（如：心功能不全） 处理 保证适宜的麻醉深度，减少刺激 消除诱因，对症处理 必要时，辅助药物治疗

九、高热、抽搐和惊厥 hyperpyrexia,hyperspasmia, eclampsia 原因 小儿的体温调节中枢未发育健全 药物诱发 处理 积极控制体温，作降温处理（重点是病人头部） 病人抽搐时立即提高吸入氧浓度，并静脉注射米 达唑仑等 排除麻醉药物（如：琥珀胆碱）引起的恶性高热

十、心肌缺血 Myocardial ischemia Etiology Myocardial ischemia is the result of an imbalance between myocardial oxygen supply and consumption and, if untreated, may lead to MI Clinical features Hemodynamic instability and ECG changes may occur with ischemia. ST segment depression greater than 1 mm or T-wave inversion may indicate subendocardial ischemia. Other indicators of ischemia include: a. Hypotension. b. Changes in central filling pressures or cardiac output. c. Regional wall motion abnormalities as detected with transesophageal echocardiography.

Treatment Hypoxemia and anemia should be corrected. ß-Adrenergic antagonists decrease myocardial oxygen consumption. Nitroglycerin reduces ventricular diastolic pressure and volume through venodilation and thus decreases myocardial oxygen demand. Phenylephrine or norepinephrine to improve myocardial perfusion pressure. positive inotropes such as dopamine dobutamine or norepinephrine are indicated. Aspirin, heparinization, thrombolytic therapy, angioplasty, and coronary revascularization may be considered in selected patients

十一、苏醒延迟 postponed resurgence 原因 麻醉药物过量 呼吸或循环功能恶化 低温 肝肾功能 严重水、电解质紊乱 糖代谢异常 处理 对症处理

十二、术中知晓 intraoperative awareness Awareness during anesthesia refers to a patient experiencing an intraoperative event and recalling the event postoperative. Etiology Awareness is associated with a poor anesthetic technique, the use of low concentration of volatile anesthetic agents and breathing system disconnec- tions and leaks. Significant degrees of intraoperative awareness occur only in patients who have received a muscle relaxant.

术中知晓的预防 (prevention) ●避免麻醉过浅 (avoiding the light anesthesia) ●监测脑电图 (monitoring electroencephalogram,EEG) ●监测脑干听觉诱发电位变化 ( monitoring the changes in the auditory evoked potential)

十三、急性肺不张 Acute pulmonary atelectasis 原因 呼吸道阻塞 预防 术前禁烟 2-3 周 急性呼吸道感染的病人延期手术 麻醉期间保持呼吸道通畅，术毕尽早拔管 处理 消除呼吸道梗阻的原因，预防感染，使萎陷的肺复张

Questions 呼吸道梗阻的原因，临床表现，预防和处理？ 全麻期间高血压的原因有哪些？ 全麻期间心肌缺血的原因与预防？