Volatile Anesthetics

Question 1

1. MAC is highest in neonates (0 to 30 days) versus other age groups with which of the following?
A. isoflurane
B. desflurane
C. sevoflurane
D. halothane
E. none of the above

Answer 1

1. C The MAC for inhalation agents varies with age. For most volatile anesthetics, the highest MAC values are for infants 1 to 6 months old. In infants younger than 1 month or older than 6 months, the MAC is lower for isoflurane, halothane, and desflurane. Sevoflurane is different. For sevoflurane the MAC for neonates 0 to 30 days old is 3.3%, for infants 1 to 6 months old is 3.2%, and for infants 6 to 12 months old is 2.5% (Hall Q321)

Question 2

2. The rate of increase in the alveolar concentration of a volatile anesthetic relative to the inspired concentration (FA/FI) plotted against time is steep during the first moments of inhalation with all volatile anesthetics. The reason for this observation is that
   A. volatile anesthetics decrease blood flow to the liver
   B. there is minimal anesthetic uptake from the alveoli into pulmonary venous blood
   C. volatile anesthetics increased cardiac output initially
   D. the volume of the anesthetic breathing circuit is small
   E. volatile anesthetics reduce alveolar ventilation

Answer 2

2. B Alveolar partial pressure of a volatile anesthetic, which ultimately determines the depth of general anesthesia is determined by the relative rates of input to removal of the anesthetic gases to and from the alveoli. Removal of anesthetic gases from the alveoli is accomplished by uptake into the pulmonary venous blood, which is most dependent upon an alveolar partial pressure difference. During the initial moments of inhalation of an anesthetic gas, there is no volatile anesthetic in the alveoli to create this partial pressure gradient. Therefore, uptake for all volatile anesthetic gases will be minimal until the resultant rapid increase in alveolar partial pressure establishes a sufficient alveolar-to-venous partial pressure gradient to promote uptake of the anesthetic gas into the pulmonary venous blood. This will occur in spite of other factors, which are discussed in the explanation to question 13. (Hall Q322)

Question 3

3. During spontaneous breathing, volatile anesthetics
   A. increase tidal volume (VT) and decrease respiratory rate
   B. increase VT and increase respiratory rate
   C. decrease VT and decrease respiratory rate
   D. decrease VT and increase respiratory rate
   E. none of the above

Answer 3

3. D At concentrations of 1 MAC or less, volatile anesthetics, as well as the inhaled anesthetic N2O, will produce dose-dependent increases in the respiratory rate in spontaneously breathing patients. This trend continues at concentrations greater than 1 MAC for all the inhaled anesthetic except isoflurane. With the exception of N2O, the evidence suggests this effect is caused by direct activation of the respiratory center in the central nervous system rather than stimulating pulmonary stretch receptors. Additionally, volatile anesthetics decrease VT and significantly alter the breathing pattern from the normal awake pattern of intermittent deep breaths separated by varying time intervals to one of rapid, shallow, regular, and rhythmic breathing (Hall Q323).

Question 4

4. Each of the following volatile anesthetics is an ether derivative EXCEPT
A. halothane
B. enflurane
C. isoflurane
D. desflurane
E. sevoflurane

Answer 4

4. A Halothane is derived from the hydrocarbon ethan by substitution with the halogens fluorine, bromine, and chlorine. The structure of this halogenated hydrocarbon makes halothane nonflammable and provides for low blood solubility, molecular stability, and anesthetic potency (Hall 324).

Question 5

5. The reason desflurane is not used for inhalation induction in clinical practice is because of
   A. its low blood/gas partition coefficient
   B. its propensity to produce hypertension in high concentrations
   C. its propensity to produce airway irritability
   D. its propensity to produce tachyarrhythmias
   E. its propensity to produce nodal rhythms

Answer 5

5. Although desflurane has a low blood/gas partition coefficient (0.42) and should produce rapid induction of anesthesia, its marked pungency and airway irritation make inhalation inductions very difficult. Not only do patients dislike the scent, but the airway irritation often leads to coughing, increased salivation, breath holding, and sometimes laryngospasm (especially if the concentration is rapidly increased). In addition, with abrupt increases in concentration, patients often develop tachycardia and hypertension, thought to be due to increased sympathetic discharge (Hall Q325).

Question 6

6. A medical group planning a trip to South America has a large supply of old enflurane vaporizers (vapor pressure = 170 mm Hg). Which volatile could be delivered through an enflurane vaporizer such that the dialed setting equaled the vaporizer’s output?
A. halothane
B. sevolfurane
C. isoflurane
D. desflurane
E. both halothane and isoflurane

Answer 6

6. B A vaporizer’s specificity is based on the vapor pressure of the anesthetic agent for which it is made. Filling a vaporizer with an agent with a higher vapor pressure results in a higher concentration in the vaporizer’s output. Similarly, a volatile agent with a lower vapor pressure produces an output with a lower concentration than seen on the dial. Enflurane vapor pressure of 172 mm Hg (20C) most closely approximates the vapor pressure of sevoflurane which is 160 mm Hg. Remember D HI SE: Desflurane (669) > Halothane (244) = Isoflurane (240) > Sevoflurane (160) = Enflurane (172). (Hall Q326).

Question 7

7. Select the true statement regarding blood pressure when 1.5 MAC N20-isoflurane is substrituted for 1.5 MAC isoflurane-oxygen.
   A. blood pressure is less than awake value, but greater than that seen with isoflurane-O2
   B. blood pressure is equal to awake value
   C. blood pressure is greater than awake value
   D. blood pressure is less than isoflurane-O2 pressure
   E. blood pressure is unchanged

Answer 7

7. A When N2O is substituted for an equal MAC value of isoflurane, the resulting blood pressure is greater than that seen with the same MAC value achieved with isoflurane as the sole anesthetic agent. When administered alone, N2O does not alter arterial blood pressure, stroke volume, systemic, vascular resistance, or baroreceptor reflexes. Administration of N2O increases heart rate slightly, which may result in a mild increase in cardiac output. In vitro, N2O has a dose-dependent direct depressant effect myocardial contractility, which is probably overcome in vivo by sympathetic activation (Hall Q327).

Question 8

8. Which of the following groups of volatile anesthetics decrease systemic vascular resistance?
   A. desflurane, sevoflurane, and isoflurane
   B. halothane and isoflurane
   C. desflurane and halothane
   D. halothane and isoflurane
   E. halothane only

Answer 8

8. A All the present-day volatile anesthetics reduce blood pressure in a dose dependent fashion. Desflurane, sevoflurane and isoflurane do this primarily through reductions in systemic vascular resistance. Halothane and the obsolete agent, enflurane, produce hypotension via direct myocardial depression (Hall Q328).

Question 9

9. With which of the following inhalation agents is cardiac output moderately increased?
A. halothane
B. sevoflurane
C. desflurane
D. isoflurane
E. nitrous oxide

Answer 9

9. E Halothane tends to decrease the cardiac output, whereas sevoflurane, desflurane, and isoflurane tend to maintain cardiac output. Nitrous oxide tends to increase cardiac output primarily because of the mild increase in sympathetic tone (Hall Q329).

Question 10

10. Select the FALSE statement about isoflurane (

Answer 10

10. D At concentration of 1 MAC, isoflurane may attenuate antigen-induced bronchospasm, presumably by decreasing vagal tone. At similar concentrations, isoflurane will not reduce cardiac output in patients with normal left ventricular function. Additionally, isoflurane will decrease stroke volume, mean arterial pressure, and systemic vascular resistance in a dose-dependent manner. Cardiac output remains unchanged because decreases in systemic vascular resistance result in a reflex increase in heart rate that is sufficient to offset the decrease in stroke volume. However, dose-dependent decreases in both stroke volume and cardiac index can be seen when isoflurane is administered in concentrations greater than 1 MAC (Hall Q330).

Question 11

11. Abrupt and large increases in the delivered concentration of which of the following inhalational anesthetics may produce transient increases in systemic blood pressure and heart rate? 
A. desflurane
B. isoflurane
C. sevoflurane
D. halothane
E. nitrous oxide

Answer 11

11. A Desflurane can (but does not always) produce an increase in blood pressure and heart rate when the concentrations are rapidly increased. This may be related to airway irritation and a sympathetic response. This has also occurred with isoflurane, but to a much less frequent and usually lower extent. The other agents listed do not cause this sympathetic response with a rapid increase in concentration. If desflurane is increased slowly or a prior dose of narcotic is given, this increase in blood pressure and heart rate may not occur (Hall Q331).

Question 12

12. Discontinuation of 1 MAC of which volatile anesthetic followed by immediate introduction of 1 MAC of which second volatile anesthetic would temporarily result in the greatest combined anesthetic potency?
A. halothane followed by desflurane
B. sevoflurane followed by desflurane
C. halothane followed by isoflurane
D. isoflurane followed by desflurane
E. isoflurane followed by halothane

Answer 12

12. A Of all the options listed, desflurane has the lowest solubility constant, which results in a very rapid rise in FA/FI. The rate of rise is very similar to that seen with nitrous oxide and results in the most rapid attainment of 1 MAC concentration once the new volatile anesthetic has been initiated. Halothane has the highest blood/gas solubility coefficient of all the options, reflecting the largest quantity of gas stored in the blood. This reservoir will result in the slowest decline in the alveolar concentration of this volatile upon discontinuation. The combination of these different solubilities ultimately will result in the highest combined MAC when 1 MAC of halothane is discontinued and 1 MAC of desflurane is introduced (Hall Q332).

Question 13

13. Cardiogenic shock has the greatest impact on the rate of increase in FA/FI for which of the following volatile anesthetics?
    A. isoflurane
    B. desflurane
    C. sevoflurane
    D. N2O
    E. the impact will be about the same for all agents

Answer 13

13. A The alveolar partial pressure of an anesthetic is determined by the rate of input relative to removal of the anesthetic from the alveoli as explained in question 12. During induction, the anesthetic gas is removed from the alveoli by uptake into the pulmonary venous blood. The rate of uptake is influenced by cardiac output, the blood/gas solubility coefficient, and the alveolar-to-venous partial pressure difference of the anesthetic. At a lower cardiac output, a slower rate of uptake of volatile anesthetic from the alveoli into the pulmonary venous blood results in a faster rate of increase in the alveolar concentration. This will result in an increased alveolar inspired gas concentration (FA/FI). Uptake of poorly soluble anesthetic gases from the alveoli is minimal and the rate of rise of FA/FI is rapid and virtually independent of cardiac output. Uptake of the more soluble anesthetics such as isoflurane, from the alveoli into the pulmonary venous blood can be considerable and will be reflected by a slower rate of rise of the FA/FI ratio. Cardiogenic shock will have the smallest impact on the most insoluble agents, such as desflurane, sevoflurane, and N2O, whereas the impact on the rate of rise of FA/FI of the relatively soluble anesthetic gases, such as isoflurane, will be more profound. Decrease CO -> decrease uptake -> faster induction. (Hall Q333).

Question 14

14. The vessel-rch group receives what percent of the cardiac output?
A. 45%
B. 60%
C. 75%
D. 90%
E. 95%

Answer 14

14. C. The vessel-rich group that receives approximately 75% of the cardiac output is composed of the brain, heart, spleen, liver, splenic bed, kidneys, and endocrine glands. It constitutes, however, only 10% of the total body weight. Because of this large blood flow relative to tissue mass, these organs take up a large volume of volatile anesthetic and equilibrate with the partial pressure of the volatile anesthetic in the blood and alveoli during the earliest moments of induction (Hall Q334).

Question 15

15. Which of the following volatile anesthetics undergoes the greatest degree of metabolism?
A. enflurane
B. isoflurane
C. halothane
D. desflurane
E. sevoflurane

Answer 15

15. Of the choices listed, halothane undergoes oxidative metabolism to the greatest extent (approximately 20%), followed by sevoflurane (approximately 3%), isoflurane (approximately 0.2%), enflurane (approximately 3%), and desflurane (approximately 0.02%). Enflurane and sevoflurane may produce fluoride ions, which can be of concern during longer cases because of their potential for nephrotoxicity. Fluoride ion-induced nephrotoxicity is characterized by the inability of the kidneys to concentrate urine, presumably by direction inhibition of adenylate cyclase activity, which is necessary for the normal function of antidiuretic hormone (ADH) at the distal convoluted tubules. This results in ADH-resistant diabetes insipidus, that is, nephrogenic diabetes insipidus characterized by polyuria, dehydration, hypernatremia, and increased serum osmolarity. (Hall 335).

Question 16

16. With a properly functioning circle system, each of the following is a potential disadvantage to low flow anesthesia EXCEPT 
A. hypercarbia
B. hypoxia
C. increased compound A exposure
D. increased carbon monoxide exposure
E. higher serum fluoride levels

Answer 16

16. A Hypoxia is always a concern with low flow or closed circuit anesthesia especially is N2) is used. Carbon monoxide can be formed when volatiles (desflurane, enflurane, isoflurane worst offenders) are exposed to desiccated CO2 absorbents containing KOH and NaOH (Baralyme and soda lime). Similarly, halothane and sevoflurane are unstable in hydrated CO2 absorbents and form compound A (with sevoflurane and a similar compound with halothane). Fluoride ions are formed in the metabolism of the obsolete volatile, enflurane as well as with isoflurane, sevoflurane and halothane (with reductive metabolism). These unwanted byproducts are ordinarily found in low concentrations with high flow anesthetic techniques because of the large volumes of fresh gas wash them away. With low flow or closed circuit anesthetic techniques, such molecules can accumulate. Since low flow or closed circuit anesthetics require, by definition, a circle system that always includes a CO2 absorber, hypercarbia is no more a concern than with high flow anesthetics. Regardless of the technique chosen, hypercarbia can exist if the absorbents are exhausted or if the one-way valves fail. (Hall 336)

Question 17

17. How would a right mainstem intubation affect the rate of increase in arterial partial pressure of volatile anesthetics?
    A. it would be reduced to the same degree for all volatile anesthetics
    B. it would be accelerated to the same degree for all volatile anesthetics
    C. There would be no change if PaO2 is 60 mm Hg or greater
    D. it would be reduced the most for poorly soluble agents
    E. it would be reduced the most for highly soluble agents

Answer 17

17. D The situation described in this question is that of a transpulmonary shunt. In patients with transpulmonary shunting, blood emerging from unventilated alveoli contains no anesthetic gas. This anesthetic-deficient blood mixes with blood from adequately ventilated, anesthetic-containing alveoli producing an arterial anesthetic partial pressure considerably less than expected. Because uptake of anesthetic gas from the alveoli into pulmonary venous blood is less than normal, transpulmonary shunting accelerates the rate of rise in the FA/FI ratio but reduces the rate of increase in the arterial partial pressure of all volatile anesthetics. The degree to which these changes occur depends on the solubility of the given volatile anesthetic. For poorly soluble anesthetics, such as N2), transpulmonary shunting only slightly accelerates the rate of rise in FA/FI ratio, but significantly reduces the rate of increase in arterial anesthetic partial pressure. The opposite occurs with highly soluble volatile anesthetics, such as halothane and isoflurane.

Question 18

18. Halothane, unlike desflurane and isoflurane, does not cause tachycardia. The most reasonable explanation for this observation is that halothane
    A. lacks intrinsic sympathomimetic properties
    B. lacks vagolytic properties
    C. causes direct cardiac depression
    D. has intrinsic parasympathomimetic properties
    E. inhibits baroreceptor reflexes

Answer 18

18. E In unanesthetized subjects, a reduction in arterial blood pressure will elicit an increase in heart rate via the carotid and aortic baroreceptor reflexes. In contrast to isoflurane, desflurane and sevoflurane, halothane profoundly inhibits these baroreceptor reflex responses. Therefore, despite reductions in arterial blood pressures by halothane, heart rate usually remains unchanged. (Hall 338)

Question 19

19. Isoflurane, when administered to healthy patients in concentrations less than 1.0 MAC, will decrease all the following EXCEPT
    A. cardiac output
    B. myocardial contractility
    C. stroke volume
    D. systemic vascular resistance
    E. ventilatory response to changes in PaCO2

Answer 19

19. A Cardiac output remains unchanged because decreases in systemic vascular resistance result in a reflex increase in heart rate that is sufficient to offset the decrease in stroke volume. However, dose dependent decreases in both stroke volume and cardiac index can be seen when isoflurane is administered in concentrations greater than 1 MAC. (Hall 339)

Question 20

20. Increased VA will accelerate the rate of rise of the FA/FI ratio the most for
    A. desflurane
    B. sevoflurane
    C. isoflurane
    D. halothane
    E. it will accelerate FA/FI for all of these equally

Answer 20

20. The rate of input of volatile anesthetics from the anesthesia machine to the alveoli is influenced by three factors: VA; the inspired anesthetic partial pressure; and the characteristics of the anesthetic breathing system. Increased VA will accelerate the rate of increase in FA/FI for all volatile anesthetics. However, the magnitude of this effect is dependent on the solubility of the volatile anesthetic. The rate of increase in FA/FI depends very little on VA for poorly soluble anesthetics because the uptake of these is minimal. In contrast, the rate of increase in FA/FI for highly soluble volatile anesthetics depends significantly on VA. Halothane is the most soluble volatile anesthetic listed in this question (blood/gas solubility coefficient 2.54). Therefore, an increase in VA will accelerate the rate of increase in FA/FI the most for halothane. Blood/gas solubility coefficients for the other volatile anesthetics are as follows: enflurane 1.90, isoflurane 1.46, sevoflurane 0.69, desflurane 0.42, and N2O 0.46. (Hall 340)

Question 21

21. Select the correct order from greatest to least for anesthetic requirement.
A. adults > infants > neonates
B. adults > neonates > infants
C. neonates > infants > adults
D. neonates > adults > infants
E. infants > neonates > adults

Answer 21

21. E Anesthetic requirement increases from birth until approximately age 3 to 6 months. Then, with the exception of a slight increase at puberty, anesthetic requirement progressively declines with aging. For example, the MAC for halothane in neonates is approximately 0.87%, in infants it is approximately 1.2%, and in young adults approximately 0.75%. A notable exception to this pattern is seen with sevoflurane. Here MAC is the highest with neonates. If the question only pertained to sevoflurane, the correct response would have been C. Hall 341.

Question 22

22. Which of the following inhalational agents is MOST likely to produce a decrease in systemic blood pressure by causing a junctional rhythm?
A. desflurane
B. halothane
C. isoflurane
D. sevoflurane
E. nitrous oxide

Answer 22

22. Although a junctional rhythm can develop after any of the drugs listed, it is most common with halothane. (Hall 342)

Question 23

23. A 31-year-old moderately obese female is receiving a general anesthetic for cervical spine fusion. After induction and intubation, the patient is mechanically ventilated with isoflurane at a vaporizer setting of 2.4%. The nitrous oxide flow is set at 500 mL/min and the oxygen flowmeter is set at 250 mL/min. The mass spectrometer displays an inspired isoflurane concentration of 1.7% and an expired isoflurane concentration of 0.6%. Approximately how many MAC of anesthesia would be represented by the alveolar concentration of anesthetic gases?
A. 0.5 MAC
B. 0.85 MAC
C. 1.1 MAC
D. 1.8 MAC
E. 2.1 MAC

Answer 23

23. C Two principles of MAC must be considered in this situation. First, MAC is additive, so the fraction of MAC of each individual gas must be added to arrive at total MAC. The second is that alveolar concentrations of soluble agents are reflected more accurately by end-expiratory concentrations rather than either inspiratory concentrations or gradients between inspiratory and expiratory concentrations. Because nitrous oxide is very insoluble it is reasonable to assume equilibrium will be established early. The inspiratory concentration of nitrous oxide approximately 0.6 MAC, should approximate the alveolar concentration. However, the expiratory concentrations of the more soluble volatile anesthetics should be used to estimate the alveolar concentration. The end-expiratory isoflurane concentration of 0.6 reflects approximately 0.5 MAC, which in addition to 0.6 MAC of nitrous oxide would be closest to answer C, 1.1 MAC. (Hall 343).

Question 24

24. The graph in the figure depicts: X axis - Time (min). Y axis - FA/FI. 3 curves labeled 1% N2O, 40% N2O, 75% N2O.
    A. the second gas effect
    B. the concentration effect
    C. the concentrating effect
    D. the effect of solubility on the rate of rise of FA/FI
    E. diffusion hypoxia

Answer 24

24. B The figure shown in this question depicts the concentration effect. Note that the inspired anesthetic concentration not only influences the maximum alveolar concentration that can be attained but also the rate at which the maximum alveolar concentration can be attained. The greater the inhaled anesthetic concentration, the faster the increase in FA/FI. A high PI is necessary during initial administration of an inhaled anesthetic. This initial high PI (i.e., input) offsets the impact of uptake into the blood and accelerates induction of anesthesia as reflected in the PA. This effect of the PI is known as the concentration effect. Clinically, the range of concentrations necessary to produce a concentration effect is probably possible only with nitrous oxide. The second gas effect is a distinct phenomenon that occurs independently of the concentration effect. The ability of the large-volume uptake of one gas (first gas) to accelerate the rate of increase of the PA of a concurrently administered companion gas (second gas) is known as the second gas effect. For example, the initial large volume uptake of nitrous oxide accelerates the uptake of companion gases such as volatile anesthetics and oxygen.

Question 25

25. The rate of induction of anesthesia with isoflurane would be slower than expected in patients A. with anemia B. with chronic renal failure C. in shock D. with cirrhotic liver disease E. with a right-to-left intracardiac shift

Answer 25

25. E The depth of general anesthesia is directly proportional to the alveolar anesthetic partial pressure. The faster the rate of increase in FA/FI, the faster the induction of anesthesia. With the exception of a right-to-left intracardiac shunt, all of the conditions listed in this question will accelerate the rate of increase in FA/FI and, thus, the rate of induction of anesthesia.

Question 26

26. A right-to-left intracardiac shunt would have the greatest impact on the rate of inhalation induction with which of the following inhalation anesthetics? A. halothane B. desflurane C. isoflurane D. it would speed up induction for all agents equally E. it would slow down induction for all agents equally

Answer 26

26. B In general, a right-to-left intracardiac shunt or transpulmonary shunt will slow the rate of induction of anesthesia. This occurs because of the dilutional effect of shunted blood, which contains no volatile anesthetic, on the arterial anesthetic partial pressure coming from ventilated alveoli. The impact of a right-to-left shunt on the rate of increase in pulmonary arterial anesthetic partial pressure and, ultimately, the rate of induction of anesthesia is greatest for poorly soluble volatile anesthetics. This occurs because uptake of poorly soluble volatile anesthetics into pulmonary venous blood is minimal; thus, the dilutional effect of the shunt on pulmonary venous anesthetic partial pressure is essentially unopposed. In contrast, the uptake of highly soluble volatile anesthetics is sufficient to partially offset the dilutional effect. Of the anesthetics listed in the question, desflurane is the least soluble. (Hall 346)

Question 27

``` 27. A left-to-right tissue shunt, such as arteriovenous fistula, physiologically most resembles which of the following? A. a left-to-right intracardiac shunt B. a right-to-left intracardiac shunt C. ventilation of unperfused alveoli D. a pulmonary embolism E. none of the above ```

Answer 27

27. A Both a left-to-right intracardiac shunt and a left-to-right tissue shunt, such as an arteriovenous fistula, will result in a higher partial pressure of anesthetic gas in the blood returning to the lungs, ultimately resulting in a more rapid rise in FA/FI. However, this effect is minimal and in most cases clinically insignificant. (Hall 347)

Question 28

28. A fresh-gas flow rate of 2L/min or greater is recommended for administration of sevoflurane because A. the vaporizer cannot accurately deliver the volatile at lesser flow rates B. it prevents the formation of fluoride ions C. it prevents formation of compound A D. it diminishes rebreathing E. none of the above

Answer 28

28. D Sevoflurane is a highly insoluble volatile anesthetic that combines with carbon dioxide absorbents to form a vinyl ether known as compound A. The blood/gas partition coefficient for sevoflurane is 0.69. The vaporizer manufactured by Ohmeda is capable of delivering concentrations ranging from 0.2% to 8% at fresh gas flow rates of 0.2 to 15 L/min. Its vapor pressure is 160 mm Hg at 20C, which is similar to the vapor pressure for the other volatile anesthetics with the exception of desflurane (664 mmHg at 20C). Gas flows greater than 2L/min prevent rebreathing compound A (not formation of it), thus reducing the possibility of renal toxicity associated with it. (Hall 348)

Question 29

``` 29. Metabolism plays an important role in the rate of rise of FA/FI during induction of anesthesia for which of the following anesthetics? A. isoflurane B. N2O C. halothane D. desflurane E. none of the above ```

Answer 29

29. E Metabolism may play an important role in emergence from anesthesia when one of the more soluble agents is used. However, this is not the case on induction. Factors that affect the rate of induction include the inspiratory concentration of anesthetic gas, alveolar ventilation, and the alveolar venous partial pressure difference.

Question 30

``` 30. Smokers are most likely to show a mild, but transient increase in airway resistance following intubation and general anesthesia with which of the following? A. isoflurane B. sevoflurane C. halothane D. desflurane E. none of the above ```

Answer 30

30. D Volatile anesthetics produce minimal bronchodilation unless airway resistance is increased (bronchospasm). This is explained by the fact that airway smooth muscle tone is ordinarily low and additional bronchodilation is difficult to demonstrate. The irritating effects of desflurane can be reduced by prior administration of fentanyl or morphine. (Hall 350).

Question 31

31. Which of the following reasons best explains the more rapid alveolar washout of halothane compared with isoflurane? A. differences in blood solubility B. differences in the blood/brain partition coefficient C. differences in the oil/gas partition coefficient D. the fact that halothane is not an ether E. increased metabolism of halothane

Answer 31

31. E Halothane undergoes significant metabolism compared to isoflurane (15-20% vs 0.2%). Metabolism increases total elimination of halothane (which occurs mainly in the liver but also occurs in the lung), resulting in a more rapid alveolar washout. (Hall 351)

Question 32

32. Graph with X axis - minutes from end of N2O anesthesia, Y axis - PaO2. A. diffusion hypoxia B. second gas effect C. context sensitive half time of desflurane D. concentration effect E. uptake of N20

Answer 32

32. A This classic graph depicts the effect of switching from 21% oxygen and 79% N2O to 21% oxygen and 79% nitrogen, that is air. When this occurs large volumes of N2O are released into the lungs and dilute all gases including oxygen and CO2. The reduction in O2 results in hypoxia and the resulting fall in CO2 reduces the drive to breathe. This combination occurs at a time when most patient have narcotics and other respiratory depressants on board. For this reason it is wise to administer 100% oxygen to patients for several minutes after emergence from general anesthesia (Hall 352).

Question 33

``` 33. Which of the following organs is NOT considered a member of the vessel rich group? A. lungs B. brains C. heart D. liver E. kidney ```

Answer 33

33. A The vessel rich group receives 75% of the cardiac output and represents 10% of the weight of a lean adult. In a sense, the lungs receive virtually 100% of the cardiac output, but this is the right sided CO (the supply side for oxygen) and therefore doesn’t “count” in the classic definition. Lung parenchyma, ironically, uses a very small quantity of oxygen compared with the brain, liver, kidney and myocardium (Hall 353).

Question 34

34. In isovolumic normal human subjects, 1 MAC of isoflurane anesthesia depresses mean arterial pressure by approximately 25%. The single BEST explanation for this is A. reduction in heart rate B. venous pooling C. myocardial depression D. decreased systemic vascular resistance E. poor ventricular filling secondary to tachycardia

Answer 34

34. D At 1 MAC concentrations, isoflurane depresses mean arterial pressures primarily by decreasing systemic vascular resistance. The decrease in mean arterial pressure may be greater than that seen with the administration of halothane. However, heart rate will be increased and stroke volume will decrease to a lesser extent than seen with administration of 1 MAC halothane (Hall 354).

Question 35

``` 35. If cardiac output and alveolar ventilation are doubled, the effect on the rate of rise of FA/FI for isoflurane compared with that which existed immediately before these interventions would be A. doubled B. somewhat increased C. unchanged D. somewhat decreased E. halved ```

Answer 35

35. B Changes in both cardiac output and alveolar ventilation will affect the rates of rise of FA/FI but in opposite directions. An increase in cardiac output will decrease the rate of FA/FI whereas an increase in alveolar ventilation will increase the rate of FA/FI. However, these two opposing options do not completely offset one another because the increased cardiac output also accelerates the quilibrium of the anesthetic between the blood and the tissues. This equilibrium results in a narrowing of the alveolar-to-venous partial pressure difference and attenuates the impact of the increased cardiac output on uptake. The net result will be a slight increase in the rate of FA/FI. (Hall 355).

Question 36

``` 36. Which of the following characteristics of inhaled anesthetics most closely correlates with recovery from inhaled anesthesia? A. blood/gas partition coefficient B. brain/blood partition coefficient C. fat/blood partition coefficient D. MAC E. vapor pressure ```

Answer 36

36. A Blood/gas partition coefficient is the option listed that most closely correlates with recovery from inhaled anesthesia. A higher blood/gas partition coefficient reflects a larger quantity of gas dissolved in the blood for a given alveolar concentration. Other factors that affect emergence from from anesthesia include the alveolar ventilation, cardiac output, tissue concentrations, and metabolism (Hall 356).

Question 37

``` 37. Which of the following inhalational anesthetics is most likely to produce a coronary steal syndrome by preferentially dilating small coronary arterial resistance vessels? A. halothane B. isoflurane C. desflurane D. sevoflurane E. nitrous oxide ```

Answer 37

37. B If an inhalation agent causes coronary artery vasodilation, it is theoretically possible to cause a condition called coronary steal syndrome. In this condition, when the perfusion pressure of the coronary artery is reduced, only blood vessels capable of dilation will dilate to compensate for the reduction in blood flow. Because atherosclerotic vessels cannot effectively dilate, they would be less likely to be able to compensate for a reduction in blood flow and hence become ischemic. The redistribution of blood causes the “steal”. Of the listed drugs, only isoflurane produces significant coronary dilation. This was once thought to be of great clinical significance but over time has been shown to be of little significance.

Question 38

38. An unconscious, spontaneously breathing patient is brought to the operating room from the intensive care unit (ICU) for wound debridement. Which of the following maneuvers would serve to slow induction of inhalation anesthetics through the tracheostomy? A. using sevoflurane instead of isoflurane (using MAC-equivalent inspired concentrations) B. increasing fresh gas flow from 2 to 6 L/min C. esmolol 30 mg IV D. increasing minute ventilation E. none of the above

Answer 38

38. E Four main factors affect the total or rate of rise of the alveolar concentration of anesthetic (FA) and hence the inhalation induction of anesthetics. These factors are the inspired concentration of anesthetic (FI), the solubility of the anesthetic, the alveolar ventilation and the cardiac output. The rate of rise in FA/FI is faster with the less soluble anesthetics, as noted by the blood:gas partition coefficients. The blood:gas partition coefficient measured at 37C is the least with desflurane (0.45) followed closely for nitrous oxide (0.47), then sevoflurane (0.65), isoflurane (1.4), enflurane (1.8), halothane (2.5) and highest with ether (12). Thus, replacing isoflurane with sevoflurane would speed up induction. Increasing the minute ventilation as well as increasing the fresh gas flow rate allow more of the anesthetic to get into the lungs and offsets the uptake of anesthetic by the blood also speeding the induction of inhalation anesthesia. Decreasing the cardiac output accelerates the rise FA/FI resulting in a faster inhalation induction (decrease amount of blood exposed to the lung and decreases the uptake of anesthesia) Hall 358.

Question 39

``` 39. Which of the settings below would give the highest arterial oxygen concentration during inhalation induction of general anesthesia with sevoflurane? A. L/min Oxygen-2, air-2, N2O-0 B. L/min Oxygen-2, air-0, N20-2 C. L/min Oxygen-2, air-2, N20-2 D. L/min Oxygen-4, air-10, N20-1 E. L/min Oxygen-2, air-3.5, N20-0 ```

Answer 39

39. B Based on “FiO2” it would appear that choices B and E are tied at 50%. The question asks for arterial oxygen concentration (not FiO2). During induction of general anesthesia, N2O is rapidly taken up into the blood, resulting in the so called second gas effect and concentrating effect. Concentration of oxygen in this manner is termed “alveolar hyperoxygenation” and results in a transient increase in PaO2 of approximately 10%. (Hall 359).

Question 40

``` 40. Inhalational anesthetics, which produce decreases in arterial pressure primarily by reduction in left ventricular after-load, include each of the following EXCEPT A. sevoflurane B. desflurane C. isoflurane D. halothane E. sevoflurane and desflurane ```

Answer 40

40. D Halothane produces reductions in arterial pressure primarily by reducing cardiac output. Desflurane, sevoflurane, and isoflurane lower arterial blood pressure through reduction in system vascular resistance with relative preservation of cardiac output. (Hall 360).

Question 41

``` 41. An anesthesia circuit is primed in preparation for an inhalation induction (with open adjustable pressure-limiting [APL] valve). The anesthesia hose is occluded with a flow of 6L/min. The anesthesia circuit (canisters, hoses, mask, anesthesia bag) contains 6L. A machine malfunction allows administration of 100% N2O. Approximately how much N2O would there be in the circuit when the malfunction is discovered at the one minute mark? A. 32% B. 48% C. 63% D. 86% E. 95% ```

Answer 41

41. C Calculation of the washin of N2O requires use of the concept of time constant. Given a volume of 6 liters for the circle system, the time constant is 6L/(6L x min-1) or one minute. The numbers to remember for time constants are 63%, 84% and 95% for the 1,2,3 time constant respectively. A properly functioning anesthesia machine would never allow administration of 100% N20, but this nightmare scenario is given purely for illustration purposes. Hall 361.

Question 42

``` 42. Which of the following factors lowers MAC for volatile anesthetics? A. serum sodium 151 mEq/L B. red hair C. body temperature 38C D. acute ethanol ingestion E. acute amphetamine ingestion ```

Answer 42

42. D Acute ethanol ingestion is the only factor listed that will reduce MAC. Acute amphetamine ingestion raises MAC, as do hypernatremia, hyperthermia and the presence of (naturally occuring) red hair. Gender, thyroid function, and PaCO2 between 15 and 99 mmHg and PaO2 greater than 38 mmHg have no effect on MAC. (Hall 362).

Question 43

43. Each of the following factors can influence the partial pressure gradient necessary for the achievement of anesthesia EXCEPT A. inspired anesthetic concentration B. cardiac output C. alveolar ventilation (VA) D. the volume of the anesthetic breathing circuit E. ventilation of nonperfused alveoli (dead space)

Answer 43

43. E Factors determining partial pressure gradients necessary for establishment of anesthesia: Input from Anesthesia Machine to alveoli: 1. Inspired anesthetic concentration, 2. Alveolar ventilation, 3. Characteristics of the anesthesia breathing system. Uptake from the Alveoli to Pulmonary blood: 1. Blood/gas coefficient, 2. Cardiac output, 3. Alveolar-to-venous partial pressure difference. Uptake from Arterial blood to Brain: 1. Brain/blood coefficient, 2. Cerebral blood flow, 3. Arterial to-venous partial pressure difference. A right to left intrapulmonary shunt affects delivery on inhaled anesthetics, but lung dead space does not, because the latter does not produce dilutional effect on the arterial partial pressure of the anesthetic in question. Hall 363

Question 44

``` 44. Which of the following volatile anesthetics is unique in containing preservative? A. sevoflurane B. desflurane C. isoflurane D. halothane E. N2O ```

Answer 44

44. D Halothane is the only modern volatile anesthetic (methoxyflurane also contained a preservative) that contains a preservative, thymol. Because halothane may ndergo degradation into chloride, hydrochloric acid, bromide, hydrobromic acid, and phosgene, it is stored in amber-colored bottles and thymol is added to prevent spontaneous oxidation. Hall 364.

Question 45

45. If the alveolar to venous partial pressure difference of a volatile anesthetic (PA-PV) is positive (i.e. PA>PV) and the arterial to venous partial pressure difference (Pa-Pv) is negative (i.e., Pv>Pa) which of the following scenarios is most likely to be true? A. the vaporizer has been shut off at the end of the case B. induction has just started C. steady state has been achieved D. the volatile anesthetic has been turned down from steady state, but not off E. the vaporizer was shut off during emergence, then suddenly turned up because the patient moved before closure of the incision

Answer 45

45. The delivery of anesthetic gases to a patient is a complex series of events that starts with the anesthesia machine and culminates with achievement of an anesthetic partial pressure in the brain (PBr). The partial pressure measured in the blood for any volatile is either rising (at first rapidly, then more slowly) or falling (rapidly at first then more slowly). The vessel-rich group reaches steady state in about 12 minutes (for any dialed level of volatile). The rest of the body, however, aproaches but virtually never reaches, equilibrium (e.g. the equilibrium half time for the fat group is 30 hours for sevoflurane). Hence, a true zero gradient is never achieved in the steady state. When the anesthetic is discontinued or reduced, there is a fall in the arterial partial pressure such that it is less than the venous partial pressure. In fact, when the venous partial pressure exceeds the arterial partial pressure it means the volatile has been reduced (or shut off) because the lungs are “cleansing” the blood as the volatile filled blood passes through them. The newly “cleansed” blood then finds its way to the left ventricle with a very low Pa for the volatile in question. The present example can only be explained if the volatile had just been turned off or down (lungs cleansing) then suddenly turned back up. In this brief “window” the alveolar partial pressure gradient would exceed the venous partial pressure because there is a net transfer of anesthetic into the blood exiting the lungs (pulmonary vein). Since this just happened (turned up), the body has not had sufficient time to reverse the gradient in the left sided arterial and venous system. Moments later, the left sided arterial volatile partial pressure will exceed the venous partial pressure and the patient will become “deeper”. Hall 365.

Question 46

``` 46. Anesthetic loss to the plastic and rubber components of the anesthetic circuit hindering achievement of an adequate inspired concentration is a factor with which of the following anesthetics? A. desflurane B. nitrous oxide C. sevoflurane D. isoflurane E. all of the above ```

Answer 46

46. D Anesthetic agents are soluble in the rubber and plastic components found in the anesthesia machine. This fact can impede the development of anesthetic concentrations of these drugs. The worst offender is the obsolete volatile methoxyflurane. However, both isoflurane and halothane are soluble in rubber and plastic, but to a lesser degree. Sevoflurane, desflurane, and nitrous oxide have little or no solubility in rubber and plastic. A different but important issue should be borne in mind regarding loss of sevoflurane. This agent can be destroyed in appreciable quantities by Baralyme and soda lime, but not calcium hydroxide lime (Amsorb). It is therefore recommended that fresh-gas flow rates exceed 2L/min when sevoflurane is administered. Hall 366.

Question 47

``` 47. Factors predisposing to formation and/or rebreathing of compound A include each of the following EXCEPT A. low fresh gas flow B. use of soda lime rather than Baralyme C. high absorbent temperatures D. fresh absorbent E. higher concentrations of sevoflurane ```

Answer 47

47. B Compound A is an ether that forms when sevoflurane interacts with absorbent granules. In rats, compound A is a nephrotoxin that causes damage to the proximal renal tubule. It is believed that compound A is not nephrotoxic in humans, at least not at the concentrations that are achieved clinically (even with fresh gas flows as low as 1L/min). The factors that lead to increased concentrations of compound A are use of fresh absorbent, use of Baralyme instead of soda lime, high absorbent temperatures, higher concentrations of sevoflurane in the anesthesia system and closed circuit or low-flow anesthesia. Desiccated Baralyme favors the formation of compound A, whereas desiccated soda lime decreases compound A formation. Hall 367.

Question 48

48. The effects of a left to right shunt such as an arteriovenous fistula on inhalation induction of anesthesia is to A. speed up induction B. slow down induction C. slow down inhalation induction only if an intracardiac (right to left) shunt also exists D. speed up inhalation only if an intracardiac (right to left) shunt also exists E. Have no effect on induction time

Answer 48

48. A left to right peripheral shunt such as an arteriovenous fistula delivers volatile containing venous blood to the lungs. This action offsets the dilutional effect of a right to left intracardiac or pulmonary shunt and speeds up induction. The increase in the anesthetic partial pressure from an AV fistula is only detectable in the setting of a concomitant right to left shunt (Hall 368).

Question 49

``` 49. The following volatiles are correctly matched with their degree of metabolism (determined by metabolite recovery). A. halothane 20% B. sevoflurane 2% C. isoflurane 0.2% D. desflurane 0.02% E. all are correctly matched ```

Answer 49

49. E Each of the volatiles is correctly paired with its percentage of recovered metabolites. Sevoflurane is metabolized 2% to 5% through oxidative pathways utilizing the cytochrome P-450 enzyme pathway. Likewise the other volatiles are all oxidatively metabolized in varying degrees. The obsolete anesthetic methoxyflurane underwent 50% metabolism resulting in high concentrations of fluoride ions and resultant renal failure in some patients. Halothane is unique among the volatiles agents in that it can undergo reductive metabolism in the face of low oxygen availability in the liver. Hall 369.

Question 50

50. Which of the components below is NOT considered in the process of “washin” of the anesthesia circuit at the onset of administration? A. inspiratory limb B. expiratory limb C. anesthesia bag D. CO2 absorber E. Mass spectrometer tubing and reservoir

Answer 50

50. E By definition, the washin of the anesthesia circuit refers to the filling of the components of the circuit with anesthetic gases. The total washin volumes are around 7L and break down as follows: anesthesia bag 3L; anesthetic hoses 2L; and anesthesia absorbent compartment, 2L. All of the components listed are part of the anesthetic circuit except the mass spectrometer tubing. The mass spectrometer takes away from incoming gases through aspiration, but does not dilute them. Hall 370.

Question 51

51. Which of the following maneuvers would NOT increase the rate of an inhalation induction? A. increasing alveolar ventilation B. substitution of desflurane for isoflurane C. overpressuring D. carrying out the induction in San Diego instead of Denver E. placement of patient on an inotropic infusion

Answer 51

51. E Increasing minute ventilation is one of two methods for manipulating ventilation to increase the rate of establishing anesthesia. Another method is increasing inspired concentration, which can be achieved by turning up the dial above desired steady state concentration (overpressurizing) to reach steady state more quickly, or increasing fresh gas flow to reduce or eliminate rebreathing (dilution). Substituting a less soluble anesthetic such as sevoflurane for isoflurane also establishes anesthesia more rapidly. Carrying out the induction in San Diego instead of Denver constitutes administrating the anesthetic at a higher atmospheric (barometric) pressure, which decreases the uptake and hence increases the rate of rise of FA/FI, that is, accelerates the establishment of anesthesia. Administration of an inotropic increases cardiac output, which also increases uptake and slows the rate of induction. uptake = Q(PA-PV)/BP where is the blood/gas partition coefficient, Q is the cardiac output, Pa-Pv is the alveolar-to-pulmonary venous blood partial pressure difference, and BP is the barometric pressure. Hall 371.

Question 52

``` 52. Which of the following anesthetics would undergo 90% elimination the most rapidly after a 6 hour Whipple procedure under one MAC for the duration of the operation? A. isoflurane B. sevoflurane C. halothane D. desflurane E. sevoflurane and desflurane are tied ```

Answer 52

52. D In comparing pharmacokinetics of elimination for volatile anesthetics, desflurane is the fastest. The time for a 50% reduction (decrement) in the alveolar partial pressure of the “modern” anesthetics is roughly the same, about 5 minutes, regardless of anesthetic duration. For longer anesthetics, however, the 80% and 90% decrement times become markedly different. In the present example, the 90% decrement time for desflurane after a six hour anesthetic is 14 minutes. This is in stark contrast to sevoflurane (65 minutes) and isoflurane (86 minutes). Hall 372)

Question 53

53. After induction and intubation of a healthy patient and placement on a ventilator, the sevoflurane vaporizer is set at 2% and fresh gas flow is 1 L/minute (50% N2O and 50% O2). The inspired concentration on the mass spectrometer one minute later is 1.4%. The MAIN reason for the different between the dial setting and the concentration shown on the mass spectrometer is A. rapid uptake of sevoflurane B. insufficient fresh gas flow for correct vaporizer function C. second gas effect D. dilution E. improper vaporizer calibration

Answer 53

53. D A properly functioning vaporizer will produce the concentration set on the dial (plus or minus a small tolerance) provided the fresh gas flow is greater than 250 mL/min and less than 15 L/min. The 1 L/min rate in this question is well within the limits of the vaporizer. The fact that rebreathing occurs with a circular anesthesia system causes a significant dilutional effect. It is true that uptake would enhance dilution, but it (uptake), per se, is not the main reason for the discrepancy. Uptake is considered when discussing the FA/FI ratio. This question addresses the characteristics of the anesthesia machine and the relationship between dial setting and delivered concentration. To achieve a desired concentration, e.g., 2%, you must either raise the fresh gas flow to convert the system to a non-rebreathing system or set the vaporizer to a high level than is actually desired, the concept of overpressurization. In this era of cost containment, the later is economical. Hall 373.

Question 54

54. After cessation of general anesthesia which consisted of air, oxygen and volatile only, the patient is placed on 100% oxygen. Each of the following serves as a reservoir for volatile anesthesia and may delay emergence EXCEPT A. rebreathed exhaled gases B. the absorbent C. the patient D. the plastic components of the anesthesia circuit E. gases emerging from the common gas outlet

Answer 54

54. E the anesthesia circuit can delay emergence significantly if the patient is not disconnected (functionally) from it. Anesthetic gases become dissolved in the rubber and plastic components of the breathing circuit. Likewise the soda lime can serve as a depository for anesthetics as well as the patient’s own exhaled gases. To reduce these effects to nearly zero, fresh gas flow should be raised to at least 5L/min. Fresh gases emerge via the common gas outlet and do not contain volatile agents or N2O since these (volatiles and N2O) are shut off during emergence. Hall 374.

Question 55

``` 55. Which of the following characteristics of volatile anesthetics is necessary for calculation of the time constant? A. blood/gas partition coefficient B. brain/blood partition coefficient C. oil/gas partition coefficient D. minimum alveolar concentration (MAC) E. saturated vapor pressure ```

Answer 55

55. B The time constant is defined as capacity divided by flow. The time constant for a volatile anesthetic is determined by the capacity of a tissue to hold the anesthetic relative to the tissue blood flow. The capacity of a tissue to hold a volatile anesthetic depends both on the size of the tissue and on the affinity of the tissue for the anesthetic. The brain time constant of a volatile anesthetic can be estimated by doubling the brain/blood partition coefficient for the volatile anesthetic. For example, the time constant of halothane (brain/blood partition coefficient of 2.6) for the brain (mass of approximately 1500 g, blood flow of 750 mL/min) is approximately 5.2 minutes. Hall 375.

Question 56

``` 56. The concept of “context sensitive half time” emphasizes the importance of the relationship between half time and A. alveolar ventilation B. blood solubility C. concentration D. duration E. anesthetic metabolism ```

Answer 56

56. D This concept highlights the fact that the difference in half time values among the volatile anesthetics is similar for all volatiles if anesthetic duration is very brief. With administration of volatile anesthetics for longer periods of time, differences in recovery time become more profound. For example, after a 1 hour anesthetic with desflurane (blood:gas tissue coefficient 0.45), a 95% reduction in the alveolar concentration can be reached in 5 minutes. With an hour long sevoflurane (blood: gas tissue coefficient 0.65), a 95% reduction requires 18 minutes and an hour long isoflurane anesthetic (blood:gas tissue coefficient 1.4) requires greater than 30 minutes to reach 95% reduction in the alveolar concentration. Hall 376.

Question 57

57. Select the FASE statement regarding time constants for volatile anesthetics. After 3 time constants A. 6 to 12 minutes have elapsed for “modern anesthetics” B. the A-VD for the brain is very small C. the expired volatile concentration will rise much less slowly than the preceding 12 minutes D. the venous blood will contain 95% of volatile content of arterial blood E. the A-VD for the rectus abdominal muscle is large

Answer 57

57. D after period of time equal to 3 time constants, the venous blood exiting the vessel rich group will be at 95% level, but the blood as a whole will have a less than 95%. The venous blood contains a mixture of blood from the vessel rich group, the muscle group, the fat group and the vessel poor group and at the 3 time constant mark will be less than 95%. Hall 377.

Question 58

58. Halothane (1 MAC) A. heart rate (HR)- no change, SVR - no change, CI- decreased B. HR- decreased, SVR- decreased, CI- decreased C. HR - no change, SVR- decreased, CI - decreased D. HR- increased, SVR - decreased, CI - decreased E. HR - increased, SVR- decreased, CI- no change or slight increase

Answer 58

58. A Halothane is unique among the volatiles listed in that it does not affect HR or SVR in the MAC ranges studied. Hall 378.

Question 59

59. Isoflurane (1 MAC) A. heart rate (HR)- no change, SVR - no change, CI- decreased B. HR- decreased, SVR- decreased, CI- decreased C. HR - no change, SVR- decreased, CI - decreased D. HR- increased, SVR - decreased, CI - decreased E. HR - increased, SVR- decreased, CI- no change or slight increase

Answer 59

59. E Hall 379

Question 60

60. Desflurane (1 MAC) A. heart rate (HR)- no change, SVR - no change, CI- decreased B. HR- decreased, SVR- decreased, CI- decreased C. HR - no change, SVR- decreased, CI - decreased D. HR- increased, SVR - decreased, CI - decreased E. HR - increased, SVR- decreased, CI- no change or slight increase

Answer 60

60. D Hall 380

Question 61

61. Sevoflurane (1 MAC) A. heart rate (HR)- no change, SVR - no change, CI- decreased B. HR- decreased, SVR- decreased, CI- decreased C. HR - no change, SVR- decreased, CI - decreased D. HR- increased, SVR - decreased, CI - decreased E. HR - increased, SVR- decreased, CI- no change or slight increase

Answer 61

61. B Hall 381