IA Review Questions

Question 1

Spontaneous ventilation will ______ the uptake of inhalation anesthetics by ________ alveolar ventilation.

A: decrease, decreasing
B: decrease, increasing
C: increase, decreasing
D: increase, increasing

Answer 1

The correct answer is: A
Volatile anesthetics exert a negative feedback loop that decreases their uptake in spontaneously ventilating patients. As the patient becomes more anesthetized, alveolar ventilation decreases, which decreases the amount of anesthetic they inhale. The use of mechanical ventilation bypasses this feedback loop.

Question 2

The administration of 1.5% isoflurane will

A: decrease total hepatic blood flow
B: decrease hepatic artery blood flow
C: increase portal vein blood flow
D: decrease portal vein blood flow

Answer 2

The correct answer is: C

The administration of isoflurane 1.5% has been shown to maintain total hepatic blood flow and hepatic artery blood flow while increasing portal vein blood flow. The use of isoflurane 1% and nitrous oxide has been shown to increase both hepatic blood flow and hepatic oxygen extraction.

Question 3

A change in alveolar ventilation would affect which inhalation agent to the greatest degree?

A: nitrous oxide
B: desflurane
C: sevoflurane
D: isoflurane

Answer 3

The correct answer is: D

Changes in alveolar ventilation affect a soluble agent more than a poorly-soluble agent. In this case, isoflurane is more soluble than sevoflurane, desflurane, or nitrous oxide, so it would be affected to the greatest degree.

Question 4

Overpressuring during an inhalation induction is acceptable with sevoflurane because it

A: is less pungent
B: is less soluble
C: undergoes less metabolism
D: has a lower molecular weight

Answer 4

The correct answer is: A

Overpressuring is the use of higher inspired concentrations of an inhaled anesthetic than the desired endpoint to achieve a faster induction speed. Overpressuring is acceptable with sevoflurane because it is less pungent and less likely to produce airway irritation.

Question 5

Which anesthetic agent undergoes the greatest degree of metabolism?

A: Nitrous oxide
B: Sevoflurane
C: Desflurane
D: Isoflurane

Question 6

Which volatile agent increases cerebrospinal fluid absorption?

A: Desflurane
B: Sevoflurane
C: Isoflurane
D: Halothane

Answer 6

The correct answer is: C

Isoflurane is unique in that it is the only volatile agent that facilitates CSF absorption and has a favorable effect on CSF dynamics.

Question 7

Which inhalation agent is the most pungent?

A: isoflurane
B: desflurane
C: sevoflurane
D: nitrous oxide

Answer 7

The correct answer is: B

Desflurane is extremely pungent and would not be appropriate for an inhalation induction because it can produce coughing, breath-holding, salivation, and laryngospasm in an awake patient.

Question 8

What percent of the cardiac output is supplied to the vessel-rich group (brain, heart, kidney, liver, and GI tract)?

A: 25
B: 50
C: 75
D: 90

Answer 8

The correct answer is: C

Question 9

What is the approximate blood/gas partition coefficient of isoflurane?

A: 0.4
B: 0.5
C: 0.7
D: 1.4

Answer 9

The correct answer is: D

The blood/gas partition coefficient of isoflurane is 1.43 (some sources cite 1.46).

Question 10

Which term describes the diversion of blood from a myocardial bed with limited or inadequate perfusion to a bed with more adequate perfusion?

A: Coronary steal
B: Robin Hood syndrome
C: Cerebral steal
D: Subclavian steal

Answer 10

The correct answer is: A

As the normal vessels dilate, blood is shunted towards the normal areas of the heart and away from the areas supplied by the already diseased vessels. This can result in worsening of ischemia.

Question 11

Imagine four anesthesia gases identified as gas A, B, C, and D. Given the oil:gas partition coefficients for each gas as follows: Gas A = 78, Gas B = 5.5, Gas C = 102, and Gas D = 2.1, which anesthetic gas would you expect to be the most potent?

Answer 11

The correct answer is: C
The oil:gas solubility coefficient provides an indication to the potency of an inhalation anesthetic. The higher the oil:gas solubility, the greater the potency. The oil:gas partition coefficient of Gas C is the highest, and it would have the greatest potency. The estimated MAC of an agent can be calculated by dividing 150 by the oil:gas coefficient. In this instance, Gas C would have the lowest MAC.

Question 13

Which term describes the administration of higher partial pressure of anesthetic than the alveolar concentration actually desired for the patient?

A: Concentration effect
B: Overpressuring
C: Second-gas effect
D: Ventilation effect

Answer 13

The correct answer is: B
Overpressurization is the administration of a higher partial pressure of anesthetic than the alveolar concentration actually desired for the patient. This is used to speed induction.

Question 14

Match the anesthetic agent with its approximate oil:gas partition coefficient.

Answer 14

99 to Isoflurane

19 to Desflurane ​

50 to Sevoflurane​

1.4 to Nitrous oxide​

Question 15

Despite having a lower blood:gas solubility coefficient, the rate of rise of the FA/Fi ratio is higher for nitrous oxide than for desflurane. This is due primarily to the

A: concentration effect
B: ventilation effect
C: second-gas effect
D: oil:gas partitioning effect

Answer 15

The correct answer is: A

Agents with a lower blood:gas partition coefficient exhibit a faster rate of rise in the FA/Fi ratio. The exception is that nitrous oxide will exhibit a faster rate of rise than desflurane despite the fact that it has a blood:gas partition coefficient of 0.47 and desflurane has a blood:gas partition coefficient of 0.42. The increase with nitrous oxide is due to the fact that it is administered in doses of 50-70% compared to 3-9% for desflurane. This is referred to as the concentration effect.

Question 16

Which inhaled anesthetic would you expect to increase heart rate the most in concentrations above 1.5 MAC?

A: sevoflurane
B: desflurane
C: isoflurane
D: nitrous oxide

Answer 16

The correct answer is: B

Desflurane, isoflurane, and sevoflurane all produce an increase in heart rate. At concentrations higher than 1.5 MAC, desflurane produces the greatest increase in heart rate. Sevoflurane can produce a mild increase in heart rate at concentrations above 1.5%, but the effect is not as pronounced as that seen with desflurane.

Question 17

You are inducing a patient undergoing surgery for an intracranial mass. What intervention would most help keep the intracranial pressure from increasing?

A: Administer desflurane at 0.8 MAC or less
B: Administer sevoflurane at 1.5-2.0 MAC
C: Maintain the PaCO2 at 45-50 mmHg
D: Encourage the patient to cough forcefully on emergence

Answer 17

The correct answer is: A

Volatile anesthetics are all capable of increasing intracranial pressure due to the increase in cerebral blood flow that they produce. This effect is most significant in patients who have a space-occupying intracranial lesion. Hyperventilation to produce a PaCO2 of 30 mmHg can help offset the increase in pressure. In the setting of hypocapnia, patients undergoing desflurane anesthesia at 0.8 MAC or less do not exhibit an increase in intracranial pressure, but at 1.1 MAC, the pressure increases by about 7 mmHg.

Question 18

Which statement is a correct summary of the Meyer-Overton rule?

A: No common chemical structure is capable of producing anesthesia
B: A reduction in body temperature lowers anesthetic requirements
C: Reversal of anesthesia can be achieved with the application of pressure
D: Potency of an anesthetic is proportional to its lipid solubility

Answer 18

Although all of the statements above are properties of inhalation anesthetics, it is the Meyer-Overton rule which states that the potency of an inhalation agent and its lipid solubility are proportional.

Question 19

Which of the following agents has been shown to increase intracranial pressure?

A: Etomidate
B: Propofol
C: Mannitol
D: Desflurane

Answer 19

The correct answer is: D

All of the volatile anesthetic agents and nitrous oxide have been shown to increase intracranial pressure. It is believed that desflurane increases intracranial pressure by altering the CSF flow dynamics in some way. Propofol and etomidate decrease intracranial pressure.

Question 20

The Ames test on the volatile anesthetics and nitrous oxide is negative. This means that these agents and their metabolites are not

A: known carcinogens
B: metabolized by the liver
C: likely to produce nephropathy
D: stable in water

Answer 20

The correct answer is: A

The Ames test identifies agents that are likely to be mutagenic or carcinogenic and is negative for isoflurane, desflurane, sevoflurane, and nitrous oxide.

Question 21

You are anesthetizing a patient with a congenital heart disease and a right-to-left shunt. The use of nitrous oxide could

A: increase the shunt due to an increase in PVR
B: increase the shunt due to a decrease in PVR
C: decrease the shunt due to an increase in PVR
D: decrease the shunt due to a decrease in PVR

Answer 21

The correct answer is: A

Nitrous oxide can produce an increase in pulmonary vascular resistance (PVR). The increase in PVR in patients with congenital heart disease could increase the severity of a right-to-left shunt, if present.

Question 22

Equipment, Instrumentation, and Technology: Inhalation Anesthetics
At 760 mmHg, the boiling point of Sevoflurane in degrees Celsius is:

A: 48.5
B: 50.2
C: 56.5
D: 58.5

Answer 22

The correct answer is: D
At 760 mm Hg, the boiling points for

Desflurane 22.8

Isoflurane 48.5

Halothane 50.2

Enflurane 56.5

Sevoflurane 58.5

Question 23

Inhalation anesthetics produce dose-dependent increases in intracranial pressure primarily because they

A: increase cerebrospinal fluid production
B: increase CO2 formation
C: increase the mean arterial pressure
D: increase cerebral blood flow

Answer 23

The correct answer is: D

Volatile anesthetics are all capable of increasing intracranial pressure due to the increase in cerebral blood flow that they produce. This effect is most significant in patients who have a space-occupying intracranial lesion. Hyperventilation to produce a PaCO2 of 30 mmHg can help offset the increase in pressure.

Question 24

Prolonged administration of nitrous oxide can produce megaloblastic changes in bone marrow due to interference in the activity of

A: hemoglobin
B: vitamin B12-dependent enzymes
C: hepatic enzymes
D: mitochondria

Answer 24

The correct answer is: B

Prolonged administration of nitrous oxide can produce megaloblastic changes in bone marrow due to interference in the activity of vitamin B12-dependent enzymes. Despite this, the administration of nitrous oxide has not been shown to have any detrimental effects in patients undergoing bone marrow transplantation.

Question 25

The composition of the inspired gas mixture delivered to the patient is dependent upon all of the following except

A: the volume of the breathing circuit
B: the cardiac output of the patient
C: the fresh gas flow rate
D: absorption by the circuit

Answer 25

The correct answer is: B
The composition of the inspired gas mixture a patient receives depends primarily upon the fresh gas flow rate, the volume of the breathing circuit, and any absorption by the circuit. The inspired gas concentration will be closer to the fresh gas concentration if the circuit volume and level of absorption by the circuit are low and the fresh gas flow is high.

Question 26

All of the volatile anesthetics below have been noted to increase right atrial pressure except for

A: nitrous oxide
B: isoflurane
C: desflurane

D: sevoflurane

Answer 26

The correct answer is: D
Nitrous oxide, isoflurane, and desflurane have all been noted to increase right atrial pressure, but sevoflurane has not. The effect of nitrous oxide on right atrial pressure is presumed to be due to increased pulmonary vascular resistance.

Question 27

What factor can increase the minimum alveolar concentration (MAC)?

A: Decreased central neurotransmitter levels
B: Hyperthermia
C: Hyponatremia
D: Lithium

Answer 27

The correct answer is: B

Increased catecholamines, hyperthermia, cyclosporine, red hair, hypernatremia, and a history of chronic ethanol abuse are factors associated with increased MAC values.

Question 28

A pediatric patient is undergoing general anesthesia for repair of a right-to-left shunt. You would expect the speed of inhalation induction to be

A: faster
B: slower
C: the same as if no shunt were present
D: it is impossible to predict the relationship between speed of an inhalation induction and presence of a shunt

Answer 28

The correct answer is: B

If a right-to-left shunt is present, an inhalation induction proceeds more slowly because the anesthetic concentration of arterial blood increases more slowly. The opposite is true with a left-to-right shunt because the rate of transfer of anesthetic from the lungs to the blood is more rapid. This effect is rarely evident in the clinical setting, however.

Question 29

An inhalation agent at equilibrium exhibits a blood concentration that is half the concentration present in the alveolar gas. This agent would have a blood:gas partition coefficient of

A: 0.5
B: 2
C: 4
D: 16

Answer 29

The correct answer is: A

The partition coefficient describes the concentration ratio of a gas at equilibrium between two locations. In this example, a blood:gas partition coefficient of 0.5 means that the blood contains half the concentration present in the alveolar gas when equilibrium is reached.

Question 30

How are cerebral metabolic rate (CMRO2) and cerebral blood flow (CBF) altered by isoflurane?

A: An increase in CMRO2 with an increase in CBF
B: An increase in CMRO2 with a decrease in CBF
C: A decrease in CMRO2 with an increase in CBF
D: A decrease in CMRO2 with a decrease in CBF

Answer 30

The correct answer is: C
The use of volatile anesthetics can result in a potentially beneficial effect during ischemia characterized by a decrease in CMRO2 with a simultaneous increase in CBF.

Question 31

What are the major groups tissues are divided into when discussing the transfer of volatile anesthetics to the tissues? (select four)

A: Muscle
B: Vascular
C: Fat
D: Skin
E: Cartilage
F: Vessel-poor
G: Vessel-rich
H: Renal

Answer 31

The correct answer is: ACFG

The four groups are the vessel-rich group, muscle, fat, and the vessel-poor group.

Question 32

Which of the following are characteristics of sevoflurane? (select two)

A: It has a vapor pressure of 238
B: It is metabolized less than desflurane
C: It has a molecular weight of 200.1
D: It contains more fluorine atoms than desflurane

Answer 32

The correct answer is: CD
Sevoflurane has a vapor pressure of 157-170 at room temperature and an oil-gas partition coefficient of 47-54. The molecular weight of sevoflurane is 200.1. Sevoflurane contains 7 fluorine atoms while desflurane contains only 6. Sevoflurane undergoes metabolism at a rate of 5-8 percent and only trace amounts of desflurane are metabolized. Isoflurane has an oil-gas partition coefficient of 90.8 and a vapor pressure of 238.

Question 33

Which inhalation agent would potentiate the effects of nondepolarizing muscle relaxants (NDMRs) the least?

A: Desflurane
B: Sevoflurane
C: Isoflurane
D: Nitrous oxide

Answer 33

The correct answer is: D

Volatile anesthetics potentiate the effects of neuromuscular blocking drugs. Most studies demonstrate that desflurane, sevoflurane, and isoflurane are roughly equal in the degree to which they potentiate NDMRs. Nitrous oxide does not demonstrate a significant potentiation.

Question 34

How much fluoride atoms does IA contain?

Answer 34

Isoflurane has 5 fluorides, desflurane has 6, and sevoflurane is the most fluorinated with 7 fluoride atoms.

Question 35

Which anesthetic agent would be taken up by the bloodstream the fastest?

A: Isoflurane
B: Sevoflurane
C: Desflurane
D: Nitrous oxide

Answer 35

The correct answer is: A

Highly soluble agents are absorbed rapidly from the alveoli into the blood and the alveolar pressure drops substantially. Because of this absorption, the alveolar concentration rises much more slowly and takes a longer time to reach the inspired concentration.

Question 36

Risk factors for experiencing bronchospasm during anesthesia include all of the following except

A: perioperative respiratory infection
B: endotracheal intubation
C: COPD
D: age greater than 70 years

Answer 36

The correct answer is: D

Factors that increase the risk for bronchospasm during anesthesia include: age less than 10 years, endotracheal intubation, perioperative respiratory infection, and COPD.
Flood P, Rathmell JP, & Shafer S. Stoeltings Pharmacology and Physiology in

Question 37

Which volatile agent doesn’t decrease the cerebral metabolic rate?

A: Isoflurane
B: Desflurane
C: Sevoflurane
D: Nitrous oxide

Answer 37

The correct answer is: D

Isoflurane, desflurane, and sevoflurane are able to decrease cerebral metabolic oxygen requirements to an equal degree. Nitrous oxide has the ability to increase the cerebral metabolic rate.

Question 38

What are two potential byproducts of sevoflurane administration?

A: fluoride
B: thiocyanate
C: compound A
D: ammonia

Answer 38

Sevoflurane may degrade into fluoride which can potentially lead to a decreased ability of the kidneys to concentrate urine. It has also been associated with the production of compound A with low-flow anesthesia. Studies indicate that there is no clinical difference in postoperative renal function in patients who were administered sevoflurane, however.

Question 39

Nitrous oxide can leave the blood and enter an air-filled cavity _____ times faster than nitrogen can leave the cavity.

A: four
B: sixteen
C: thirty-four
D: fifty-eight

Answer 39

The correct answer is: C

Because the blood:gas partition coefficient of nitrous oxide is about 34 times greater than the blood:gas partition coefficient of nitrogen, it can leave the blood and enter an air-filled cavity 34 times faster than nitrogen can exit the cavity and enter the blood. Because of this, nitrous oxide can expand or increase the pressure in air-filled anatomical spaces.

Question 40

The concentration of an inhalation anesthetic that prevents skeletal muscle movement to painful stimuli in 50% of patients is known as

A: MAC
B: MAC-BAR
C: the loading dose
D: the LD50

Answer 40

The correct answer is: A
The mean alveolar concentration (MAC) of an inhalation agent is the concentration that prevents skeletal muscle movement to painful stimuli in 50% of patients.

Question 41

Which agent has the lowest blood:gas partition coefficient?

A: Desflurane
B: Nitrous oxide
C: Isoflurane
D: Xenon

Answer 41

The correct answer is: D

Xenon has a blood:gas partition coefficient of 0.115, which is even lower than nitrous oxide (0.46) and desflurane (0.42). Although it is an effective anesthetic agent, xenon is rarely used because of a prohibitively high cost.

Question 42

Which of the following agents is most likely to increase the systemic vascular resistance?

A: sevoflurane
B: isoflurane
C: desflurane
D: nitrous oxide

Answer 42

The correct answer is: D
All modern volatile anesthetics decrease the blood pressure in a dose-dependent fashion by decreasing vascular resistance. Nitrous oxide, however, increases the SVR by activating the sympathetic nervous system.

Question 43

Which term accurately describes the phenomenon that occurs during the recovery from anesthesia in which the washout of high concentrations of N20 can lower alveolar concentrations of oxygen and carbon dioxide?

A: Ventilation effect
B: Diffusion hypoxia
C: Elimination effect
D: Perfusion effect

Answer 43

The correct answer is: B

During anesthetic recovery, high concentrations of N2O exiting via the alveoli can decrease the alveolar concentrations of oxygen, resulting in a phenomenon called diffusion hypoxia.

Question 44

Equipment, Instrumentation, and Technology: Inhalation Anesthetics

At 760 mmHg, the boiling point of Desflurane in degrees Celsius is:

A: 22.8
B: 48.5
C: 50.2
D: 56.5

Answer 44

The correct answer is: A
At standard pressure, the boiling points for inhalation anesthetics in degrees Celsius are: Desflurane-22.8, Isoflurane-48.5, Halothane-50.2, Enflurane-56.5, and Sevoflurane-58.5.

Question 45

What are the components of the vessel-rich group? (select three)

A: Brain
B: Skin
C: Heart
D: Hair
E: Bones
F: Kidney
G: Muscle
H: Adipose tissue

Answer 45

The correct answer is: ACF
The vessel-rich group consists of the brain, heart, liver, kidneys, and endocrine organs. They constitute about 10% of body weight but receive about 75% of cardiac output.

Question 46

Simultaneous administration of a relatively slow agent such as isoflurane and a faster drug such as nitrous oxide (in high concentrations) to speed the onset of the slower agent is referred to as

A: the concentration effect
B: overpressuring
C: the second-gas effect
D: the ventilation effect

Answer 46

The correct answer is: C

The combined administration of a potent inhaled anesthetic with nitrous oxide can increase the alveolar concentration of the volatile anesthetic as the nitrous exits the alveoli and enters the bloodstream more rapidly. This is referred to as the second-gas effect.

Question 47

Volatile anesthetics produce dose-dependent ______ in uterine smooth muscle tone and ______ in uterine blood flow in parturients.

A: increases, increases
B: increases, decreases
C: decreases, increases
D: decreases, decreases

Answer 47

The correct answer is: D
Volatile anesthetics produce dose-dependent decreases in uterine blood flow and uterine smooth muscle tone in parturients. The changes are mild at 0.5 MAC and become significant at 1.0 MAC.

Question 48

Which of the following techniques will speed emergence from general anesthesia when using a volatile anesthetic?

A: underpressurization
B: using low fresh gas flows
C: using a more soluble inhaled anesthetic
D: increasing the minute ventilation

Answer 48

The correct answer is: D

Just like the speed of induction, the recovery from inhalation anesthesia is dependent upon the solubility of the anesthetic, the cardiac output, and the minute ventilation. The lower the agent solubility, higher the cardiac output, and larger the minute ventilation, the faster emergence will occur. Unlike induction, in which you can use over-pressurization to speed the onset of anesthesia, you can’t under-pressurize at emergence simply because you can’t reduce the inspired anesthetic below zero.

Question 49

As the inspired partial pressure (PI) of an inhaled anesthetic is increased, the rate at which the alveolar partial pressure increases to meet the PI increases. This is known as the

A: concentration effect
B: second-gas effect
C: Bernoulli principle
D: Coanda effect

Answer 49

The correct answer is: A
The inhaled partial pressure of a gas, known as PI influences the alveolar partial pressure of a gas (the PA). The concentration effect simply states that the higher the PI is, the faster the PA approaches the PI. Or, the higher the inspired partial pressure of the gas, the faster the partial pressure in the alveolus will rise to match it.

Question 50

How are cortical somatosensory evoked potentials affected by the administration of volatile anesthetics?

A: Latency and amplitude both increase
B: Latency and amplitude both decrease
C: Latency increases and amplitude decreases
D: Latency decreases and amplitude increases

Answer 50

The correct answer is: C

Volatile anesthetics produce an increase in the latency and decrease in the amplitude of the cortical component of somatosensory evoked potentials. The decrease in amplitude is more pronounced than the increase in latency.

Question 51

Which of the following statements is false?

A: Females with naturally red hair have a higher MAC for desflurane
B: Hypercapnia decreases MAC
C: Pregnancy increases MAC
D: Acidosis decreases MAC

Answer 51

The correct answer is: C

Pregnancy decreases MAC. Hypoxia, hypercapnia, acidosis, and hypotension all decrease MAC. It has been demonstrated that natural redheads have a significantly higher anesthetic requirement for desflurane than do non-redhead patients.

Question 52

Which rule states that the potency of an inhaled anesthetic and its oil:gas partition coefficient are directly proportional?

A: Potent Solubility rule
B: Rule of nines
C: Liebermeister’s rule
D: Meyer-Overton rule

Answer 52

The correct answer is: D

The Meyer-Overton rule states that the potency of an inhalation agent and its lipid solubility are proportional. That means, that as the oil:gas solubility of an agent increases, its potency increases, and its MAC value decreases. The rule of nines is used to estimate the surface area of a burn. Liebermeister’s rule states that for every Celsius degree increase in a fever, the heart rate increases 8 beats per minute.

Question 53

Which of the following statements are correct? (select two)

A: The FA:FI difference of a volatile anesthetic is directly proportion to its rate of uptake
B: The FA:FI difference of a volatile anesthetic is indirectly proportional to its rate of uptake
C: The rate of induction with a volatile anesthetic is directly proportional to its rate of uptake
D: The rate of induction with a volatile anesthetic is inversely proportional to its rate of uptake

Answer 53

The correct answer is: AD

The FA:FI difference of a volatile anesthetic is directly proportion to its rate of uptake, but the rate of induction with a volatile anesthetic is inversely proportional to its rate of uptake.

Question 54

Which anesthetic agent is most associated with a transient increase in liver enzyme levels?
A: Isoflurane
B: Sevoflurane
C: Nitrous oxide
D: Desflurane

Answer 54

The correct answer is: D
The administration of desflurane is associated with transient increases in liver enzyme levels, but isoflurane is not.

Question 55

A theoretical inhalation anesthetic has an oil:gas solubility coefficient of 100. The estimated MAC for this anesthetic would be approximately

A: 50
B: 10
C: 7.5
D: 1.5

Answer 55

The correct answer is: D

MAC is related to the oil:gas solubility coefficient of an anesthetic agent. One way to estimate the approximate MAC of an agent is to divide 150 by the oil:gas coefficient. In this case, 150 divided by 100 would equal an estimated MAC of 1.5%.

Question 56

Modern volatile anesthetics decrease the blood pressure primarily by their effect on

A: ejection fraction
B: cardiac contractility
C: systemic vascular resistance
D: heart rate

Answer 56

The correct answer is: C

Modern volatile anesthetics decrease the blood pressure in a dose-dependent fashion by decreasing vascular resistance.

Question 57

Minimum alveolar concentration (MAC) decreases by ____ percent per decade.

A: 3
B: 6
C: 8
D: 10

Answer 57

The correct answer is: B

Minimum alveolar concentration (MAC) decreases by six percent per decade.

Question 58

Below are the blood:gas partition coefficients for four imaginary inhalation anesthetics. Which one would exhibit the slowest induction?

A: 0.5
B: 0.6
C: 0.75
D: 0.92

Answer 58

The correct answer is: D
The anesthetic with a blood:gas coefficient of 0.92 will exhibit a slower induction. The higher the blood:gas coefficient, the greater the uptake of the anesthetic and the longer it will take for the FA/FI to equal 1.0.

Question 59

An increase in cardiac output would slow the onset of which inhalation anesthetic the most?

A: Nitrous oxide
B: Desflurane
C: Sevoflurane
D: Isoflurane

Answer 59

The correct answer is: D

The higher the blood:gas partition coefficient is, the more the onset will be slowed by an increase in cardiac output. The blood:gas partition coefficient of isoflurane is about 1.4, for sevoflurane it is about 0.7, for desflurane it is 0.42, and for nitrous oxide it is about 0.47.

Question 60

What is the approximate blood/gas partition coefficient of sevoflurane?

A: 0.4
B: 0.5
C: 0.7
D: 1.4

Answer 60

c

Question 61

Substituting a fluorine atom for the chlorine atom on the alpha-ethyl component of isoflurane will produce

A: nitrous oxide
B: sevoflurane
C: desflurane
D: xenon

Answer 61

The correct answer is: C

Substituting a fluorine atom for the chlorine atom on the alpha-ethyl component of isoflurane will produce desflurane.

Question 62

The vapor pressure of desflurane is __________ times that of other contemporary inhaled anesthetics.

A: 1 to 2
B: 3 to 4
C: 5 to 6
D: 7 to 8

Answer 62

The correct answer is: B
The vapor pressure of desflurane is 3-4 times that of the other inhaled anesthetics and boils at 22.8 C which is slightly above normal room temperature.

Question 64

The oil:gas partition coefficient for sevoflurane is about

A: 0.7
B: 10
C: 50
D: 150

Answer 64

The correct answer is: C

The oil:gas partition coefficient for sevoflurane is about 50 (sources vary from 50 to 55) and its blood:gas partition coefficient is about 0.7 (sources vary between 0.68 and 0.69).