General anesthesia

Question 1

What are the 2 main categories of General anesthesia agents

Answer 1

1. intravenous
2. inhaled

Question 2

During induction what is the significance of preoxygenation

Answer 2

this gives them a reservoir of oxygen for the period between when they lose consciousness and are successfully intubated and ventilated

Question 3

What drugs are given as premedication to GA

Answer 3

Benzodiazepines e.g midazolam
Opiated to reduce pain and hypertensive response to the laryngoscope
alpha 2 adrenergic agonist e.g clonidine which can help with sedation and pain

Question 4

What is the triad of general anesthesia

Answer 4

1. hypnosis
2. muscle relaxation
3. analgesia

Question 5

What some of the hypnotic agents used in GA

Answer 5

Intravenous
-propofol
-ketamine
-thiopental
-etomidate
Inhaled
-sevoflurane
-desflurane
-isoflurane
-nitrous oxide

Question 6

How do the muscle relaxants work

Answer 6

-block the neuromuscular junction from working

Question 7

What are the drugs commonly used as muscle relaxants ?

Answer 7

Depolarising
-Suxamethonium
Nondepolarizing
-rocuronium and atracurium

Question 8

What analgesic drugs do we often use in GA

Answer 8

Opiates
- fentyl
morphine

Question 9

What is emergence

Answer 9

the process of waking up the patient from GA.

Question 10

What are the risks of GA

Answer 10

1. sore throat
2. aspiration
3. dental injury
4. anaphylaxis
5. malignant hyperthermia

Question 11

Stage I (Analgesia) Guedel’s sign depth of anesthesia

Answer 11

Definition: The patient remains conscious with normal reflexes and has reduced sensation to pain.
Characteristics: Mild sedation, drowsiness, but capable of voluntary movement.

Question 12

Stage II (Excitement)

Answer 12

This stage is marked by uncontrolled movement, irregular breathing, and reflexes.
Characteristics: Excitement, delirium, irregular breathing, possible vomiting, and pupil dilation.

Question 13

Stage III (Surgical Anesthesia)

Answer 13

Definition: The ideal stage for surgery where muscle relaxation occurs, reflexes are absent, and breathing stabilizes.
Divided into 4 planes:
Plane 1: Eyelid reflex disappears; breathing becomes regular.
Plane 2: Loss of corneal and laryngeal reflexes.
Plane 3: Complete muscle relaxation, pupils dilate, loss of deep tendon reflexes.
Plane 4: Diaphragmatic breathing only; risk of paralysis.

Question 14

Stage IV (Medullary Paralysis)

Answer 14

Definition: Overdose stage where severe depression of the central nervous system occurs, leading to respiratory and circulatory failure.
Characteristics: Apnea, pupils maximally dilated, risk of death without intervention.