General anesthesia involves inducing a state of unconsciousness during surgery through the use of drugs. The goals are amnesia, hypnosis, analgesia, and immobility. Preparation includes evaluations of the patient's airway, medical conditions, medications, and labs. Monitoring is established and intravenous access and fluids are given. Induction involves preoxygenation before administering intravenous or inhalational drugs to induce unconsciousness and allow intubation. Maintenance of anesthesia involves increasing the depth of unconsciousness through volatile gases, IV drugs, or combinations while monitoring vital signs and homeostasis. Emergence and extubation involve ensuring the patient meets criteria like being awake, responsive, with full strength before discharge from recovery. Transport is the

1. Dr. Wesam Farid Mousa
Ass. Prof. Consultant of Anesthesia and ICU
Dammam University

2. Overview
• What is general anesthesia?
• Preoperative preparation
• Induction: Deparutre
• Maintenance: Flying
• Emergence: Landing
• Transport

3. What is general anesthesia
• Primary goals
Amnesia
Hypnosis
Analgesia
Immobolity

4. • Secondary goals
Medical condition
Surgical procedures
Surgical settings

5. 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?

6. Preoperative preparation
• Preoperative evaluations for:
Airway examination
Pt’s medical condition
Medications
Laboratory data
Consultant notes
Last oral intake

7. • Preoperative hydration and correction of intravascular
volume as needed:
Intravenous access
Fluid or blood transfusion as needed
• Prescribe preoperative medications as needed:
e.g. Anxiety: Benzodiazepine: Midazolam
Pain: Opioid or NSAI
Increased gastric acidity: cimetidine, omeprazole

8. Monitoring
Standard monitoring for GA
Qualified anesthetist presence
ECG
NBP
Pulse oximetry
Capnography

10. Induction
Let the pt go off to sleep
Preoxygenation
8L~10L/min
IV or Inhalational
induction
Airway management

11. 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

12. Maintenance
Increasing depth of anesthesia
stageⅠ
Amnesia
Loss of
consciousness
Stage Ⅱ
Delirium
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

13. Maintenance Anethesia
• Volatile
• Nitrous oxide-opioid relaxant technique
• IV anesthesia
• Combinations

14. • Maintain homeotasis
Vital signs
Acid-base balance
Temperature
Coagulation
Volume status

15. Maintain Ventilation
1. Spontaneous or assisted ventilation
2. Controlled ventilation
Tidal volume: 10-12ml/kg
Respiratory rate: 8-10 breaths/min

16. Maintain Intravascular Volume
 1. fluids
Crystalloid sollutions:
Colloid sollutions:
 2. Blood & blood products

17. Emergence from GA

18. Extubation
• Awake extubation
Indications
Risk of aspiration
Difficult airways
Tracheal or maxillofacial surgery

19. • Awake extubation
Criteria
 Awake
 Hemodynamically stable
 Full muscle strength
 Able to follow simple verbal
commands
 Breathing spontaneously with
adequate ventilation

20. • Deep extubation
Indications
Severely asthmatic patients
Middle-ear surgery
Open-eye surgery
Inguinal herniorrhaphy

21. • Deep extubation
Criteria
Sufficient anaesthetic depth to
avoid response to airway
stimulation
Spontaneous breathing with
adequate ventilation

22. Goals to be met before discharge from
recovery:
awake
Responsive
Full muscle strength
Adequate pain control

23. Transport
It is the responsibility of the
Anaesthetist

24. Questions