Volatile Anesthetics

Question 1

Characteristics of An ideal inhaled anesthetics

Answer 1

Non-flammable
Easily vaporized at ambient temperature
Low blood solubility (rapid on & off)
Minimal metabolism
Skeletal muscle relaxation
Non-irritating to airways
Bronchodilation
Absent myocardial depression, cerebral vasodilation, hepatic and renal toxicity.

Question 2

Ethers

Answer 2

Sevo and des

Question 3

Alkanes

Answer 3

cyclopropane and halothane

Question 4

N2O down side

Answer 4

PONV, poor wound healing and can also make pnx worse

Question 5

New anesthetics charac teristics

Answer 5

non flammable and fluorinated

Question 6

general anesthesia definition

Answer 6

It is a controlled state of unconsciousness, accompanied by partial or complete loss of protective reflexes, including the inability to independently maintain an airway or respond purposefully to verbal command

Question 7

conscious sedation

Answer 7

It is a state of mind obtained by IV administration of combination of anxiolytics, sedatives and hypnotics &/or analgesic that render the patient relaxed, yet allows the patient to communicate, maintain patent airway and ventilate adequately.

Question 8

deep sedation

Answer 8

It is a depressed level of consciousness with some blunting of protective reflex, although it remains possible to arouse the patient.

Question 9

Iatro sedation

Answer 9

A general term used for any technique of anxiety reduction in which no drugs are given
Relief of anxiety through the doctor’s behavior - it is one of the form of psychosedation

Question 10

Effects of full fluorination

Answer 10

Low potency (low oil:gas solubility which equals a higher mac)
higher vapor pressure (lower IM attraction)
higher resistance to biotransformation (less metabolism=less TFA makes an immune mediated hepatitis less likely)

Question 11

MAC bar

Answer 11

no autonomic nervous response

Question 12

Meyor overton rule

Answer 12

Halothane>Iso>Sevo>Des>N2O

Question 13

Critical Volume hypothesis

Answer 13

How anesthetics work at the receptor level and how they affect

Question 14

Theories of anesthetic action

Answer 14

Unitary hypothesis of narcosis
Meyer-overton rule
Critical volume hypothesis

Question 15

How can the mechanisms of action of inhalation anesthetics

Answer 15

macroscopic, microscopic, molecular

Question 16

Synaptic

Answer 16

Gaba, glycine and NMDA

Question 17

Amnesia

Answer 17

hyppocampus and amygdala

Question 18

hypnosis/consciousness

Answer 18

RAS and thalamus

Question 19

What excitatory receptors are blocked by VA?

Answer 19

Glutamate, serotonin and nicotinic

Question 20

What inhibitory receptors are augmented by VA?

Answer 20

Gaba and glycine

Question 21

Percentage that gases are metabolized by liver

Answer 21

Sevo 2-5%
Iso 0.2%
Des 0.02%
N20 0.004%

Question 22

Fi determined by

Answer 22

FGF rate, breathing-circuit volume, circuit absorption

Question 23

Fa is determined by

Answer 23

uptake, ventilation and concentration effect.

Question 24

Fa arterial gas concentration affected by

Answer 24

ventilation/perfusion mistmatching

Question 25

Pharmacokinetics of inhaled anesthetics in the older population

Answer 25

Increased fat- give Des Decreased hepatic function-no sevo/halothane Decreased FRC-faster induction Decreased CO- faster induction Decreased albumin- affects solubility of agents so if you have less it will be less soluble in blood therefore increasing onset

Question 26

vapor pressure

Answer 26

The pressure of the vapor over the liquid at equilibrium

Question 27

Henrys law

Answer 27

states that for a given solvent at a given temperature, the amount of gas dissolved in solution is directly proportional to the pp of the gas.

Question 28

Partial pressure in Alveoli

Answer 28

Depth of anesthesia Recovery from anesthesia Anesthetic equal potency (MAC

Question 29

What determines alveolar partial pressure?

Answer 29

Input(delivery) and uptake (loss)

Question 30

Input

Answer 30

``` Inspired PP Alveolar minute ventilation Characteristics of the breathing system FRC Anatomical dead space ```

Question 31

Uptake from alveoli to arterial blood

Answer 31

Blood gas partition coefficiend Cardiac output Alveolar to venous pp difference

Question 32

Uptake from arterial blood to brain

Answer 32

Brain blood partition coefficient | Cerebral blood flow

Question 33

Alveolar ventilation inflow factors

Answer 33

Larger the FRC = slower rise in PA | Smaller the FRC= faster rise in PA

Question 34

What is the tissue uptake dependent on?

Answer 34

tissue blood flow blood to tissue partial pressure blood tissue solubility coefficient