INHALATION AGENTS

Question 1

Although the mechanism of action of inhalation

anesthetics remains unknown, it is assumed that their ultimate effect depends on ____________

Answer 1

Attainment of a therapeutic tissue concentration in the central
nervous system. T

Question 2

There are many steps between the administration of an anesthetic from a vaporizer and its

Answer 2

deposition in the brain

Question 3

FRESH gas flow is determined by the

Answer 3

Vaporizer and the flow meter settings

Question 4

Inspired Gas concentration (FI) is determined by

Answer 4

Fresh Gas flow rate
Breathing circuit volume
Circuit absorption

Question 5

Alveolar Gas concentration (FA) is determined by

Answer 5

Uptake
Ventilation
Concentration effect and 2nd Gas effect (concentrating effect, augmented inflow effect)

Question 6

Fa (arterial gas concentration) is affected by

Answer 6

Ventilation/ Perfusion mismatching

Question 7

What does (MAC) stand for?

Answer 7

Minimum alveolar concentration

Question 8

MAC of Inhaled anesthetic is the

Answer 8

alveolar concentration that prevents movement in 50% of patients in response to a standardized stimulus (eg, surgical incision)

Question 9

Why is MAC useful (MAP)

Answer 9

MAC is a useful measure because it
• Mirrors brain partial pressure
• Allows comparisons of potency between agents
• Provides a standard for experimental evaluations

Question 10

Anesthetic uptake produces a characteristic curve that

relates the__________to ______

Answer 10

rise in alveolar concentration to time.

Question 11

The shape of this graph (anesthetic uptake) is

determined by

Answer 11

The uptakes of individual tissue groups.

Question 12

The rate of rise of anesthetic slows as the

Answer 12

Vessel-rich group—and eventually the muscle group

—reach their capacity.

Question 13

Vessel rich group are _____kg and _______%CO

Answer 13

10kg; 75%

Question 14

Muscle group are _____kg and _______%CO

Answer 14

50kg; 19%

Question 15

Fat groups are _______ and _______% CO

Answer 15

20kg ; 5%

Question 16

Vessel POOR group are ____kg and _____–% CO

Answer 16

20kg; 1%

Question 17

The impact of tissue storage depends on

Answer 17

1. the duration of anesthesia

2. Solubility of the anesthesia in various tissue compartments

Question 18

The initial steep rate of uptake is due to

Answer 18

unopposed filling of the alveoli by ventilation.

Question 19

Elimination of inhaled anesthetics is reflected by

Answer 19

the decrease in the alveolar concentration (FA) COMPARED WITH the concentration present at
the conclusion of anesthesia (FAO).

Question 20

The most important route for elimination of inhalation anesthetics is

Answer 20

the alveolus.

Question 21

Many factors that speed induction also speed recovery:

EHL LDHI

Answer 21

• Elimination of rebreathing
• High fresh gas flows
• Low anesthetic-circuit volume
• Low absorption by the anesthetic circuit
• Decreased solubility
• High cerebral blood flow (CBF)
• Increased ventilation.

Question 22

An increase in the duration of anesthesia during a constant dose of anesthetic (1.6 MAC) is associated with

Answer 22

increases in the time to recovery, with the greatest increases occurring with the most blood-soluble anesthetics.

Question 23

Decrease in MAP reflects a

Answer 23

decrease in Systemic Vascular Resistance (SVR) verses a

decrease in Cardiac Output

Question 24

Halothane lowers MAP by________CO, whereas_______ is unchanged.

Answer 24

decreasing CO; SVR

Question 25

Dose-dependent reduction of arterial blood pressure is due to _______

Answer 25

direct myocardial depression;

Question 26

2.0 MAC of halothane results in a

Answer 26

50% decrease in blood pressure and cardiac output.

Question 27

Halothane, Isoflurane, Desflurane, and Sevoflurane
on systemic vascular resistance (dynes/sec/cm5)
when administered to healthy volunteers.

Answer 27

Halothane (from 1200 to about 1100) Unchanged
Isoflurane (from 1400 to about 750)
Desflurane(From 900 to about 500)
Sevoflurane (From 990 to about 750)I

Question 28

Decrease in MAP reflects a decrease in

Answer 28

Systemic Vascular Resistance (SVR) verses a decrease in Cardiac Output

Question 29

Dose related decreases in SVR is minimized by:

Answer 29

substitution of Nitrous Oxide for a portion of Volatile Drug

Question 30

Nitrous Oxide causes _______or______in MAP when administered alone

Answer 30

unchanged or mildly increases

Question 31

Nitrous oxide (N2O; laughing gas) is the only

Answer 31

inorganic anesthetic gas in clinical use

Question 32

• At low concentrations ( 0.25 mac) Isoflurane causes

Answer 32

linear, dose dependent heart rate increase

Question 33

• Heart Rate increases minimally with

Answer 33

Desflurane concentrations of less than one MAC

Question 34

• A dose dependents increase in Desflurane is reflected by a:

Answer 34

linear increase in Heart Rate

Question 35

Inhaled anesthetics produce drug specific and dose-dependent

Answer 35

increases in PaCO2.

Question 36

Gas exchange becomes progressively less efficient at

Answer 36

deeper levels of anesthesia

Question 37

Substitution of Nitrous Oxide (60%) for equivalent portion of volatile anesthetic may attenuate

Answer 37

the increased Paco₂

Question 38

Inhaled anesthetics produce similar dose-dependent

Answer 38

decreases in the ventilatory responses to carbon dioxide.

Question 39

Blunting of ventilation with inhaled anesthetics may be

Answer 39

less pronounced in patients undergoing surgery

Question 40

Volatile anesthetics all blunt the___________

Answer 40

ventilatory stimulation evoked by arterial hypoxemia