General Anaesthetic (General)

Question 1

General Anesthetic

Answer 1

Exerts its effects on CNS leading to loss of sensation and consciousness

Question 2

Local Anesthetic

Answer 2

Blocks peripheral nerve conduction and all sensation. No loss of consciousness

Question 3

Analgesic

Answer 3

Selectivity blocks sensation of pain without blocking other modalities

Question 4

Anesthetic vs Analgesia

Answer 4

Anesthetic = Loss of sensation/consciousness (motor and autonomic)

Analgesia = Loss of painful sensation

Question 5

How are general anesthetics administered.

What are the two methods of administration

Answer 5

Administered systemically
–> Allows them to disperse everywhere

Intravenous Administration
Inhalation Administration

Question 6

Intravenous vs Inhalation (Onset)

Answer 6

Intravenous is more rapid than Inhalation

Question 7

Intravenous vs Inhalation (Elimination Speed)

Answer 7

Intravenous has slow elimination, will last a while in circulation

Question 8

Intravenous vs Inhalation (Metabolic Degration)

Answer 8

Inhalation drugs enter through lungs and undergo metabolic degration

Question 9

What anesthetic route is best for induction?

Answer 9

Intravenous Agents

Question 10

What anesthetic route is best for Maintaining Anesthesia?

Answer 10

Inhalation Agents
- Intravenous Agents must be continuously administered

Question 11

What determines the kinetics of inhalation drugs

Answer 11

Inspired air and Blood stream

Question 12

Intravenous vs Inhalation (Maintenance Anesthesia)

Answer 12

Intravenous has slow recovery –> Not used for maintenance

Inhalation has quick elimination –> Can be used for maintenance

Question 13

Intravenous vs Inhalation (Metabolism)

Answer 13

Intravenous requires body to metabolize drug
–> Slow Metabolism

Metabolic Degradation does not play a role in Inhalation and does not effect duration of action

Question 14

Lipid Soluble effect on General Anaesthetic

Answer 14

The more lipid soluble a drug is the more potent it is

Question 15

Where do anaesthetics bind

Answer 15

Hydrophobic pockets of specific membrane proteins

Question 16

What do general anesthetics affect (neural)

Answer 16

Decreases neuron excitability rather than axonal conduction

Question 17

Main Mechanism of General Anaesthetic

Answer 17

GABA(A) Receptors

General Anaesthetic potentiate action of GABA –> Enhances Cl- entry intro cells causing Hyperpolarization

Question 18

Main Mechanism of Inhalation Anaesthetics

Answer 18

Two Pore Domain K+ Channels causing Hyperpolarization

Question 19

Main Mechanism of Nitrous Oxide and Ketamine

Answer 19

NMDA Receptors

Drugs bind to receptors reducing/blocking NMDA Receptor Response

Question 20

Blood:Gas Partition Coefficient

Answer 20

Measures solubility in blood

Question 21

What does a low Blood:Gas Partition Coefficient mean

Answer 21

Low Coefficient = Lower Solubility = Faster onset/offset of anesthesia

(Due to faster equilibrium with alveoli)

Question 22

Oil:Gas Partition Coefficient

Answer 22

Measures solubility in fat

Question 23

What does a High Oil:Gas Partition Coefficient mean

Answer 23

High Coefficient = High Lipid Solubility = High Potency = Delays Recovery from Anaesthesia

Question 24

Balanced Anaesthesia

Answer 24

Mixing other drugs so that anaesthesia provides other effects
- Sedative
–> Benzodiazepine
- Prevent Bradycardia
–> Atropine
- Neuromuscular block for relaxation
–> Vecuronium
- Reverse neuromuscular block
–>Neostigmine
- Analgesic for pain:
–>Morphine