Dr. Wesam Farid MousaAss. Prof. Consultant of Anesthesia and ICU
Dammam University
Overview• What is general anesthesia?• Preoperative preparation• Induction: Deparutre• Maintenance: Flying• Emergence: Landing • Transport
What is general anesthesia• Primary goals
Amnesia Hypnosis Analgesia
Immobolity
• 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 for: Airway examination Pt’s medical condition Medications Laboratory data Consultant notes Last oral intake
• Preoperative hydration and correction of intravascular volume as needed:Intravenous accessFluid or blood transfusion as needed
• Prescribe preoperative medications as needed:
e.g. Anxiety: Benzodiazepine: Midazolam Pain: Opioid or NSAI
Increased gastric acidity: cimetidine, omeprazole
Monitoring
Standard monitoring for GA
Qualified anesthetist presence
ECG
NBP
Pulse oximetry
Capnography
Teperature (American)
Oxygen analyzer (Canadian)
InductionLet the pt go off to sleep
Preoxygenation
8L~10L/min
IV or Inhalational
induction
Airway management
Induction techniques• Intravenous: the most common method
• Inhalation: for special pt (as pt with difficult airway, pediatric pt)
• Intramuscular :rarely used, only used in uncooperative pts and young children
MaintenanceIncreasing depth of anesthesia
stageⅠ
Amnesia
Loss of
consciousness
Stage ⅡDelirium
Injurious responses
to noxious stimuli
Stage Ⅲ
Surgical anesthesia
Painful stimulation does
not elicit somatic reflexes
or deleterious autonomic
responses
Stage Ⅳ
Overdosage
Circulatory
failure
Maintenance Anethesia • Volatile
• Nitrous oxide-opioid relaxant technique
• IV anesthesia
• Combinations
•Maintain homeotasisVital signsAcid-base balanceTemperatureCoagulationVolume status
Maintain Ventilation1. Spontaneous or assisted
ventilation
2. Controlled ventilation Tidal volume: 10-12ml/kg Respiratory rate: 8-10 breaths/min
Maintain Intravascular Volume
1. fluidsCrystalloid sollutions:Colloid sollutions:
2. Blood & blood products
Emergence from GA
Extubation• Awake extubationIndications Risk of aspiration Difficult airways Tracheal or maxillofacial surgery
• Awake extubation Criteria Awake Hemodynamically stable Full muscle strength Able to follow simple verbal
commands Breathing spontaneously with
adequate ventilation
• Deep extubationIndications Severely asthmatic patients Middle-ear surgery Open-eye surgery Inguinal herniorrhaphy
• Deep extubationCriteria Sufficient anaesthetic depth to
avoid response to airway stimulation
Spontaneous breathing with adequate ventilation
Goals to be met before discharge from recovery:
awake Responsive Full muscle strength Adequate pain control
TransportIt is the responsibility of the
Anaesthetist
Questions