静脉全麻.ppt

第八章 静脉全身麻醉Intravenous anesthesia,1.Introduction,Definition General anesthesia maybe produced by many drugs which are administered via intravenous injection and depress the central nervous system.,Rapid induction of anesthesia Non-irritant to the respiratory tract No environmental pollution Making patient comfortable Rapid recovery Simply to use,Advantages,No muscle relaxation Poor control Poor analgesia,Disadvantages,Intravenous basal anesthesia Intravenous induction of anesthesia Intravenous maintenance of anesthesia,Classifications,Bolus induction of anesthesia,minor operation Intermittent injection Continuous infusion Target-controlled infusion(TCI),Methods,2.Intravenous Anesthesia of Thiopentone Sodium,Methods,Bolus（2-2.5%）short procedures or induction of anesthesia adults:2.54.5 mg/kg young children:5-6 mg/kg elder:2.5-3 mg/kg Basal anesthesia for children:2.5%,15-20 mg/kg,i.m-induce sleep in 5 min 5-10%,44 mg/kg,rectal administration-induce sleep in 10-15 min,intermittent injection,首次3-5ml，递增5-10ml，意识消失，睫毛反射消失，疼痛刺激无反应，开始手术 每2-3分钟，注药1-2ml 成人总量0.5g，最大剂量0.75-1.0g,Continuous infusion,辅助麻醉，解痉、控制惊厥 0.1%-0.5%，20-100滴/分钟滴注 蓄积、中毒,Indications,Induction Maintenance Basal narcosis Treatment of status epilepticus and convulsion Assistant of other anesthesia Reduction of intracranial pressure,Absolute Contraindications,Airway obstruction Porphyria Previous hypersensitiving reaction,Precautions,Cardiovascular disease(hypovolaemia,myocardial disease,cardiac valvular stenosis)Severe hepatic disease Renal disease Muscle disease Reduced metabolic rate,Precautions,Obstetrics Outpatient anesthesia Adrenocortical insufficiency Extremes of age(neonate,infant)Asthma,Complications,Phlebitis Tissue necrosis Intra-artery injection:endarteritis Severe cardiovascular and respiratory depression Allergic reaction Laryngeal spasm Bronchospasm Coughing and hiccups,3.Intravenous Anesthesia of Ketamine,Methods,肌肉注射法(intramuscular injection)Children 4-6 mg/kg，1year increased to 10mg/kg 1-5min起效，维持15-25分钟 追加首量1/21/3 静脉注射法（intravenous injection）首量 1-2mg/kg，1-2min起效，维持5-10min 追加：首量的1/2或全量 总量 6mg/kg,连续静脉输注法（continuous intravenous injection）1-2mg/kg induction,0.1%ketamine，iv by drip,maintenance of anesthesia,氯胺酮亚分离麻醉(analgesia without loss of consciousness)0.5(0.25-0.5)mg/kg,iv 50 ng/kg/min,Indications,Superficial operation with minor and short procedure Basal narcosis in children for regional anesthesia(pediatric anesthesia)Induction of anesthesia for children,shock or hypovolemia patient Assistant of epidural anesthesia or nerve block(analgesia and sedation)Elderly or high-risk patient:may stable circulatory and respiratory system function Anesthesia for asthmatic patients,Absolute Contraindications,Airway obstruction Raised intracranial pressure,Precautions,HypertensionCardiovascular disease,cardiac failure and anginaProlonged operationsHyperthyroid and chromaffinoma epilepticus and mental confusion,Complications,Blood pressure increased(Bp)Intracranial pressure increased(ICP)Intraocular pressure increased Agitation,night mares or hallucination Transient apnoea,respiration depresssalivationNausea and vomittingTransient blindness Laryngeal spasm and airway obstruction,4.羟丁酸钠静脉麻醉 药物特点：低毒、催眠作用强，作用时间长，循环、呼吸、肝肾功能影响小,麻醉方法 术前用药：阿托品足量 麻醉诱导：成人 50-80mg/kg 儿童可达100mg/kg 麻醉维持：复合应用，作用时间60-90min,1-2小时追加半量,适应症与禁忌症,适应症：麻醉诱导辅助麻醉或基础麻醉禁忌症严重高血压心脏传导阻滞或左束支传导阻滞心动过缓癫痫和惊厥病人,并发症,锥体外系兴奋表现低钾血症幻觉、激动、兴奋、躁狂恶心、呕吐、甚至大小便失禁,5.Intravenous Anesthesia of Propofol,Rapid induction Favorable recovery Short lasting duration Antiemetic effect,Advantages,Induction：2 mg/kg ivMaintenance：2 mg/kg iv 50-150 g/kg/min 4-12 mg/kg/hr Sedation：25-75 g/kg/min,Dosage and Administration,Indications,Induction of anesthesia Total venous anesthesia Outpatient anesthesia Sedation in ICU Sedation during surgery(Regional analgesic and endoscopy),Disadvantages,Cardiovascular depressionRespiratory depression Excitatory phenomenaPain on injection Allergic reaction,Absolute Contraindications,Airway obstruction Hypersensitivity 3 years old,5.Intravenous Anesthesia of Etomidate,Rapid acting and recovery Less depression of cardiovascular and respiratory Short duration of action,Advantages,Disadvantages,Depression of the synthesis of cortisol by the adrenal gland,Induction：0.3 mg/kg(0.1-0.4 mg/kg)Maintenance：Administration sole only for short procedures,Dosage and Administration,Indications,Induction of anesthesiaAnesthesia for compromised cardiovascular system,cardiac failure,shock patient Outpatient anesthesia,Contraindications,Airway obstruction Porphyria Adrenal insufficiency Long-term infusion,Complications,Pain on injection Nausea and vomittingVenous thrombosisRestlessness and delirium during recoveryMyopalmus,myoclonia or convulsion,6.Intravenous Anesthesia of Fentanyl,Analgesia potency is powerful Onset of action is rapid Cardiovascular depression is slight,Advantages,Induction of anesthesia 6-8 g/kg 10-20 g/kg for cardiovascular surgeryMaintenance of anesthesia Total dosage may up to 50-100 g/kg for cardiovascular surgery,Dosage and Administration,HR,Bp(large doses)Chest wall rigidity Delayed respiratory depression intraoperative awareness,Disadvantages,Indications,Induction of anesthesia Sedation and analgesiaCardiovascular anesthesia Trauma General Surgery Neurosurgery,7.Intravenous Anesthesia of Midazolam,Water-soluble benzodiazepine Slightly more rapid onset and action Short duration of action Elimination half-life is 1.5-2.5h,in some critically ill patients is prolonged up to 21h and greatly delayed recovery consciousness.,Advantages,Dosage and administration,Sedation:2.5-7.5 mg iv in adult 2.5 mg iv in elderly patients,induction:0.1-0.4 mg/kg,lower dosage,maintenance:amnesia Preventing intraoperative awareness,Indications,Induction of anesthesia Maintenance of anesthesia Sedation Premedication,Complications,Cardiovascular depression in the hypovolemic patientsRespiratory depression in elderly Recovery is prolonged in critically ill patients,