Exam 2: Inhalational Agents

Question 1

Characteristics of ether:

Answer 1

Easy to make and administer
Potent
Not organotoxic
Highly flammable

Question 2

Characteristics of chloroform:

Answer 2

Pleasant odor and nonflammable
Hepatotoxin 
Severe CV depressant
High incidence of death
Difficult to administer

Question 3

First halogenated hydrocarbon anesthetic:

Answer 3

Fluroxene; withdrawn due to organ toxicity

Question 4

Characteristics of methoxyflurane:

Answer 4

Nonexplosive, nonflammable halogenated methyl ethyl ether
Most potent of volatile agents: MAC 0.16
B/G coeff 12
Metabolites nephrotoxic

Question 5

Areas affected to produce hypnosis/sedation and immobility with GA:

Answer 5

Hypnosis/sedation: cortex, hippocampus

Immobility: spinal cord

Question 6

Meyer-Overton theory:

Answer 6

Absorption of anesthetic molecules expands hydrophobic region of lipid bilayer, distorts membrane, alters membrane function

Question 7

Fluidization theory:

Answer 7

Binding of anesthetic molecules to lipid bilayer modifies membrane structures, alters conductance or induces conformational change in channels

Question 8

Lipid theory:

Answer 8

Demonstrates a correlation between anesthetic potency and lipid solubility

Question 9

Protein/lipid interface theory:

Answer 9

Anesthetics displace lipids necessary for protein function

Question 10

Protein receptor theory:

Answer 10

Anesthetics occupy protein receptor sites and block ionic conductance during membrane excitation

Question 11

Guedel’s four stages of anesthesia:

Answer 11

1. Amnesia/analgesia
2. Delirium/excitement
3. Surgical anesthesia (4 planes)
4. Overdose

Question 12

Pupils/resp pattern/pulse/BP in stage I:

Answer 12

Pupils normal and reactive
Respirations regular, small?
Pulse irregular
BP normal

Question 13

Pupils/resp pattern/pulse/BP in stage II:

Answer 13

Pupils dilated, overreactive to light
Respirations irregular
Pulse irregular and fast
BP high

Question 14

Pupils/resp pattern/pulse/BP in stage III:

Answer 14

Pupils normal, unresponsive
Respirations fast, small
Pulse steady and slow
BP normal

Question 15

Pupils/resp pattern/pulse/BP in stage IV:

Answer 15

Pupils dilated and unresponsive
Respirations minimal and irregular
Pulse weak and thready
BP low

Question 16

Only inorganic anesthetic gas:

Answer 16

Nitrous oxide

Question 17

N2O most commonly used in combination with:

Answer 17

Induction agent, NMB, opioids, and/or VA

Question 18

C2HClBrF3 is:

Answer 18

Halothane

Question 19

C2HOClF5 is:

Answer 19

Isoflurane

Question 20

C3H2OF6 is:

Answer 20

Desflurane

Question 21

C4H2OF7 is:

Answer 21

Sevoflurane (with SEVen F’s)

Question 22

Lower weight halogens add:

Answer 22

Less potency than higher weight ones

Question 23

Chloride substitution effects on VA:

Answer 23

More stability, but myocardial depression

Question 24

Fluoride substitution effects on VA:

Answer 24

Reduction in flammability, but also potential for renal damage

Question 25

Factors that do *not* affect MAC:

Answer 25

``` Species Sex Gender Duration of anesthesia Acid-base disturbances PaO2 ```

Question 26

Factors that decrease MAC:

Answer 26

``` ↑ age Hypothermia Hyponatremia Hypotension Hypoxemia Anemia Pregnancy Drugs (benzos, opioids, ketamine, α2 agonists, LAs) ETOH (acutely) ```

Question 27

Factors that increase MAC:

Answer 27

Hyperthermia CNS stimulants Less than 1 y/o

Question 28

% of MAC that will make 95% of patients immobile to stimulus:

Answer 28

1.3 * MAC

Question 29

MAC awake is:

Answer 29

The concentration that permits voluntary response

Question 30

MAC awake of des/sevo/iso:

Answer 30

1/3 MAC

Question 31

MAC awake of halothane:

Answer 31

1/2 MAC

Question 32

MAC awake of N2O:

Answer 32

60% of MAC

Question 33

Mechanism by which halothane potentiates arrythmias:

Answer 33

↓ SA node depolarization; prone to junctional rhythms | ↓ AV node, purkinje conduction

Question 34

Epi max doses when using halothane:

Answer 34

10ml 1:100k or 20ml 1:200k within 10 min | 30ml 1:100k or 60ml 1:200k within an hour

Question 35

Presentation of VA-associated hepatitis:

Answer 35

Fever, anorexia, nausea, chills, myalgias, rash, fever, arthralgia, and eosinophilia --> jaundice 3-6 days later

Question 36

Risk factors for VA-associated hepatitis:

Answer 36

``` Prior exposure #1 Age > 40 Obesity Female gender Mexican ethnicity Genetic susceptibility Multiple brief procedures in short amt of time Enzyme induction ```

Question 37

Enzyme that metabolizes VAs:

Answer 37

CYP 450 2E1

Question 38

Pathogenesis of VA-associated hepatitis:

Answer 38

2E1 oxidizes VAs to yield reactive intermediates that bind covalently to hepatocellular macromolecules, triggering immunologic response --> massive hepatic necrosis