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General Anesthesia (GA). What’s general anesthesia ? How to anesthetize the patient ?. Four clinical end points of GA. Classification of General Anesthesia. Inhalational GA Intravenous GA Combined GA. Procedure of GA. Induction from awake to sleep (hypnotic) and ready for surgery
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What’s general anesthesia? • How to anesthetize the patient?
Classification of General Anesthesia • Inhalational GA • Intravenous GA • Combined GA
Procedure of GA • Induction from awake to sleep(hypnotic) and ready for surgery • preoxygenation • induction with intravenous or inhalational anesthetics • Tracheal intubation , mechanical ventilation • Maintenance four endpoints • Emergence Awake, spontaneous respiration no residual muscle relaxation
Tracheal intubation • Open and seal the air way • ventilation • Deliver inhalational anesthetics stiletto
Special Apparatus McCoy Mccoy Polio Polio Soper Soper Hinged blade tip
Supraglottic Devices Combitube Laryngeal Mask Airway
Difficult airway Apparatus Tracheotomy
Verify Position • chest expansion bilaterally • listening over the epigastrium and the lung fields • Continuous waveform capnography • exhaled CO2 ,esophageal detector device (EDD) • If in doubt, laryngoscope to visualize the tube passing through the vocal cords • If still in doubt, bag-mask ventilation • chest x-ray (when feasible) above the carina
Anesthetic Machine • Composition of AM • Gas supplies • Vaporizer • ventilator • Breath circle
Neuromuscular Function • TOF
Autonomic stability evaluation ECG SPO2 BP CVP T
BIS Autonomic stability evaluation PETCO2 Sevoflurane BIS
What about analgesia ? MAC Spinal reflex Intravenous GA analgesic
Emergence • Conscious • Spontaneous respiration Head rise5 s , tongue protrude VT > 500ml SpO2 >95% (inspiration air) • No residual relaxation TOF ratio > 90% • Analgesia PCA
Special techniques for management of anesthetized patient
Deliberade Hypotension • Methods • Inhalational anesthetics • isoflurane • Vasodilator • Nitroprusside sodium • Nitroglycerine • Autonomic ganglia blocker • Objectives • facilitate surgery • decrease blood loss • Safety stand • ≥70 % of Basic lever • SAP ≥ 80mmHg • MAP ≥ 60~70mmHg • Time limit • 30~90 min
Hypothermia • Objectives • Decrease MR • Maintain Basic metabolic requirement of Cell • Grades • Low hypothermia 35 ℃ ~ 32 ℃ • Middle hypothermia 31 ℃ ~ 26 ℃ • Deep hypothermia <25 ℃ • Methods • Extracorporeal • Cardiopulmonary Bypass
Cardiopulmonary Bypass • Basic parts of the Set • Preload and hemodilution HCT 20%~25% Hb 70 ~ 80 g/L • Heparin 300~400 U / kg ACT>480~ 600s • Pup flow2.2~2.8L/(m2.min) 100~150 ml/kg (child) • Myocardial protectionK+ 20mmol/L
Autologous transfusion Preoperational hemodilution ANH 10~15ml/kg Blood Salvages anticoagulation Prof. Wang Xue-ren xrwang@mail.hust.edu.cn
The best safety lies in f e a r