1. Lecture Title : General Anesthesia
Lecturer name:
Lecture Date:

2. Lecture Objectives.. Students at the end of the lecture will be able to:
Define general Anaesthesia
Learn about several agents used on induction of general anaesthesia including intravenous agents, inhalation agents, neuromuscular blocking agents and reversal agents.
Understand basic advantages and disadvantages of these agents.
Complications commonly encountered during general anaesthesia

3. General anesthetics have been performed since 1846 when Morton demonstrated the first anesthetic (using ether) in Boston, USA.
Local anesthetics arrived later, the first being scientifically described in1884.

4. General anesthesia is described as a reversible state of unconsciousness with inability to respond to a standardized surgical stimulus.
In modern anesthetic practice this involves the triad of: unconsciousness, analgesia, muscle relaxation.

5. Anesthetic plan A good anesthetic begins with a good plan.
There is no rigid format for planning anesthesia.
Each plan is adapted to each case.
The fundamental goal of anesthetic management is
to provide safety,
comfort and convenience, first for the patient and second for those caring for the patient.

6. Anesthetic plan
After a good plan, a good preparation is required for a good anesthetic.
 Before every anesthetic, every anesthesiologist should go through a checklist of necessary items including,
anesthesia machine,
ventilator,
oxygen and nitrous supply check,
suction device,
monitors and anesthesia cart.  

7. Anesthetic plan Before bringing the patient to the operating room,
the proper verification of patient's identity,
the planned procedure and
the site of the procedure should be carried out by the anesthesiologist.
All the preparations should be completed before the patient enters the room including the placement of a working peripheral intravenous line.

8. Anesthetic plan The primary goals of general anesthesia are
to maintain the health and safety of the patient while providing amnesia, hypnosis (lack of awareness), analgesia, and optimal surgical conditions (e.g., immobility).
Preoperative planning involves
the integration of pre-,
intra-, and
postoperative care.
Flexibility is an essential
multiple approaches to
induction,
maintenance, and
emergence should be considered.

9. Anesthetic plan Preoperative planning involves the integration of
intra-, and
postoperative care.
Flexibility is an essential
Multiple approaches to
induction,
maintenance, and
emergence should be considered.

10. Anesthetic plan The plan should include the following:
A premedication.
Need standard ASA monitors. However, if the patient may experience large hemodynamic fluctuations, invasive monitoring should be considered (e.g., central venous pressure for volume monitoring, arterial line for potential hemodynamic instability).
A review of anesthetic options; general anesthesia, regional anesthesia, and combinations thereof should be reviewed and options appropriate for the patient listed in the final assessment.
Plan for postoperative pain control.

11. NPO status NPO, Nil Per Os, means nothing by mouth
Solid food: 8 hrs before induction
Liquid: 4 hrs before induction
Clear water: 2 hrs before induction
Pediatrics: stop breast milk feeding 4 hrs
before induction

13. Premedication Guidelines for prophylaxis for pulmonary aspiration
Histamine (H2) antagonists
Cimetidine (Tagamet), ranitidine (Zantac), significantly reduce the volume and the acidity of gastric secretions.
Metoclopramide (Reglan) enhances gastric emptying
Midazolam (Versed) provides excellent amnesia and sedation.
Lorazepam (Ativan) may also be used but can cause more prolonged amnesia and postoperative sedation. It should not be given intramuscularly.
Opioids are not usually given as premedication unless the patient has significant pain

14. THE MONITORS Standard ASA monitoring :-
Oxygenation (oxygen analyzer, pulse oximetry)
Ventilation (capnography, minute ventilation), respiratory rate (under regional anesthesia)
Circulation (electrocardiogram [ECG], arterial blood pressure, perfusion assessment),
Temperature.

15. General Anesthesia Monitor Preoxygenation
Induction ( including RSI & cricoid pressure)
Muscle relaxants
Mask ventilation
Intubation & ETT position comfirmation
Maintenance
Emergence

16. Airway exam Mallampati classification Class I:
uvula, faucial pillars, soft palate visible
Class II:
faucial pillars, soft pillars visible
Class III:
soft and hard palate visible
Class IV:
hard palate visible

17. Sniffing position

18. Mask and airway tools

19. Mask ventilation and intubation

20. Oral and nasal airway

21. Intubation

22. Intubation

24. Laryngeal view

25. Laryngeal view scoring system

26. Difficult airway

27. Fiberoptic scope intubation

28. Trachea view Carina view

29. Glidescope

30. Fast track LMA

31. LMA

32. Induction agents Opioids – fentanyl Propofol, Thiopental and Etomidate
Muscle relaxants:
Depolarizing
Nondepolarizing

33. Induction
IV induction
Inhalation induction

34. General Anesthesia Reversible loss of consciousness Analgesia Amnesia
Some degree of muscle relaxation

35. Intraoperative management
Maintenance
Inhalation agents: N2O, Sevo, Deso, Iso
Total IV agents: Propofol
Opioids: Fentanyl, Morphine
Muscle relaxants
Balance anesthesia

36. Intraoperative management
Monitoring
Position – supine, lateral, prone, sitting, Litho
Fluid management
- Crystalloid vs colloid
- NPO fluid replacement: 1st 10kg weight-
4ml/kg/hr, 2nd 10kg weight-2ml/kg/hr and
1ml/kg/hr thereafter
- Intraoperative fluid replacement: minor
procedures 1-3ml/kg/hr, major procedures 4-
6ml/kg/hr, major abdominal procedures 7-10/kg/ml

37. Intraoperative management Emergence
Turn off the agent (inhalation or IV agents)
Reverse the muscle relaxants
Return to spontaneous ventilation with adequate ventilation and oxygenation
Suction upper airway
Wait for pts to wake up and follow command
Hemodynamically stable

38. Postoperative management
Post-anesthesia care unit (PACU)
- Oxygen supplement
- Pain control
- Nausea and vomiting
- Hypertension and hypotension
- Agitation
Surgical intensive care unit (SICU)
- Mechanical ventilation
- Hemodynamic monitoring

39. General Anesthesia Complications and Management
Respiratory complication
- Aspiration – airway obstruction and pneumonia
- Bronchospasm
- Atelectasis
- Hypoventilation
Cardiovascular complication
- Hypertension and hypotension
- Arrhythmia
- Myocardial ischemia and infarction
- Cardiac arrest

40. General Anesthesia Complication and Management
Neurological complication
- Slow wake-up
- Stroke
Malignant hyperthermia

41. Case Report Arterial oxygen desaturation following PCNL
大林慈濟醫院麻醉科 陳炳碩

42. The Patient Patient : 73 y/o Female BW 68 kg, BH 145 cm (BMI 32)
Chief complaint :
Right flank pain (stabbing, frequent attacks)
General malaise and fatigue

43. The Patient Past history : Hypertension under regular control
Senile dementia (mild)
Preoperative diagnosis : Right renal stone (3.2 cm)
Operation planned : Right PCNL (percutaneous nephrolithotomy)

45. Pre-anesthetic Assessment
EKG : Normal sinus rhythm
CXR : Borderline cardiomegaly & tortuous aorta
Lab data : Hb 10.5 / Hct 33.2
BUN 24 / Creatinine 1.1
GOT 14
PT, aPTT WNL

46. Preop

47. Anesthetic Technique General anesthesia with endotracheal intubation
Standard monitoring apparatus for ETGA
Induction : Fentanyl ug/kg
propofol 2mg/kg
Succinylcholine 80 mg
Atracurium 25 mg
Endotracheal tube (ID 19cm
Maintenance: Isoflurane 2~3% in O2 0.5 L/min
Position: prone
Blood loss : 300 mL → PRBC 2U

48. Intra-operative Events
Stable hemodynamics
Abnormal findings 30 minutes after surgery started
Increased airway pressure 35~40 mmHg
SpO2 dropped to 90~95%
Bilateral breathing sounds were still audible then
Management : Solu-cortef 100 mg IV stat
Aminophylline 250 mg IV drip
Bricanyl 5 mg inhalation

49. Intra-operative Events
ABG data pH
7.2
PaO2
90.5
PaCO2
66.8
HCO3-
26.0 BE
-2.4
Na+
143.0
K +
4.0
Ca2 +
1.1
Hb/Hct
11.4/36.1

50. Post-operative Course
The patient’s condition was kept up until the end of surgery
SpO2 90~92% after the patient was placed in the supine position
again with diminished breathing sound over right lower lung
The patient was transferred to SICU for further care (*)
Chest X-ray was followed in SICU

51. Immed.
Postop

52. Preop
Immed. Postop

53. Postoperative Course Pigtail drainage in SICU
Pleural effusion : bloody
RBC numerous
WBC 7800 (Seg 94%)
Gram stain (-)
Impression : Right hydrothorax and hemothorax

54. s/p pigtail

55. Immed. Postop
s/p pigtail

56. Postoperative Course Extubation and transfer to ordinary ward
Pigtail removed

57. Reference book and the relevant page numbers..

58. Thank You 
Dr.
Date: