6.administration of general anesthesia全身麻醉应用

,Administration of General Anesthesia,What is general anesthesia?,Preoperative preparation,Induction of anesthesia,Maintenance,Emergence from general anesthesia,Transport,*,*,*,Administration of General Anesthesia,What is general anesthesia?,Preoperative preparation,Induction of anesthesia,Maintenance,Emergence from general anesthesia,Transport,*,*,*,what do you see in the picture?,An anesthesia machine,A beautiful and smart anesthetist,Administration of General Anesthesia,Xiao Ying 肖颖,The First Affiliated Hospital of,Sun Yat-sen University,Mar 2021,Overview,What is general anesthesia?,Preoperative preparation,Induction:going off to sleep,Maintenance:keeping pt asleep,Emergence:waking up,Transport,What is general anesthesia,Primary goals,Safety is top priority,Amnesia:no memory of the event,Hypnosis:unconcious,Analgesia:free of pain,Block certain autonomic reflexes,Optimal surgical conditions:immobolity,What is general anesthesia,Secondary goals,Medical condition,Surgical procedures,Surgical settings,Examples for secondary goals,Patients with CAD:Oxygen supply-demand balance,Neurosugery:ICP control,brain relaxation and CPP maintenance,Obstetrics:anesthetics and fetal depression,difficult airway,Day surgery vs Inpatient:which kind of analgesic you should choose to minimize postoperative pain and decrease PONV?,Preoperative preparation,Preoperative evaluations,Airway examination,Interim changes in pts condition,Medications,Laboratory data,Consultant notes,Last oral intake,Preoperative preparation,Intravascular volume,Dehydration:adequately hydrate the pt before induction,Intravenous access,Preoperative medications,Anxiety,Benzodiazepine:Midazolam,Opioid:Morphine or Fentanyl,Neutralize gastric acid and decrease gastric volume,Which kind of pt is at increased risk of aspiration of gastric content?,Recent meal,Trauma,Bowel obstruction,Pregnancy,History of gastric surgery,Increased intra-abdominal pressure,History of active reflux,Monitoring,Standard monitoring for GA,ECG,NBP,Pulse oximetry,Capnography,Oxygen analyzer,Induction,Let the pt go off to sleep,Preoxygenation,8L10L/min,IV or Inhalational induction,Airway management,Induction techniques,Intravenous:the most common method,Inhalation:for special pt(pt with difficult airway,pediatric pt),Intramuscular:rarely used,only used in uncooperative pts and young children,Airway management,ASA Closed Claims Study(美国麻醉学会已结案的诉讼,35%of claims are RESPIRATORY events,90%resulted in brain damage or death,90%resulted from Difficulty in INTUBATION or EXTUBATION,Airway management,Airway patency is critically important,Oral airway,Nasophryngeal airway,Laryngeal mask airway,Intubation,Maintenance,Increasing,depth of anesthesia,stage,Amnesia,Loss of consciousness,Stage,Delirium,Injurious responses to noxious stimuli,Stage,Surgical anesthesia,Painful stimulation does not elicit somatic reflexes or deleterious autonomic responses,Stage,Overdosage,Circulatory failure,Maintenance,Maintain homeotasis,Vital signs,Acid-base balance,Temperature,Coagulation,Volume status,Maintenance,Lack of awareness and no memory of the event,Incidence of awareness,High risk surgical population,High risk pt,High risk anesthesia method,How to avoid awareness,To recognize the high risk pt,Monitor the depth of anesthesia,Somatic and autonomic response are nonspecific and unreliable,Bis monitor for high risk pt,Depth of anesthesia,Intensity of surgical stimulation,Response suggesting inadequate anesthetic depth:,Somatic:movement,coughing,changes of respiratory pattern,Autonomic:tachycardia,hypertension,mydriasis,sweating,tearing,Unreliable and nonspecific,Sympathetic activation may be caused by other reasons,Maintenance methods,Volatile(Isoflurane,Desflurane or sevoflurane combined with nitrous oxide),Nitrous oxide-opioid relaxant technique,IV anesthesia,Combinations,General anesthesia combined with regional anesthesia,Ventilation,Ventilation,1.Spontaneous or assisted ventilation,2.Controlled ventilation,Tidal volume:10-12ml/kg,Respiratory rate:8-10 breaths/min,3.Assessment of ventilation,Capnography,Pulse oximeter,Airway pressure,Reservoir breathing bag,Ventilator bellow,Ventilation,Peak inspiratory pressure,High airway pressure 2530cmH,2,O,Breathing circuit problem,ETT obstruction or movement,Altered lung compliance,Change in muscle relaxation,Surgical compression,IV Fluids,Intraoperative IV fluids requirements,1.Maintenance fluid requirements,2.Third space losses and insensible losses,3.Blood losses,IV Fluids,1.Crystalloid sollutions:maintenance fluid requirement,evaporative losses,and third space losses,2.Colloid sollutions:replace blood loss or restore intravascular volume,3.Blood transfusion,Intravascular volume assessment,Trends of heart rate,blood pressure,and urine output,Central venous pressure,pulmonary artery occlusion pressure,right and left end-diastolic volumes(using TEE)and cardiac output,Hemotocrit,platelet count,fibrinogen concentration,prothrombin time,thromboplastin time,Emergence from GA