Chapter 12 Egan's Testbanks

Gaseous diffusion

1 and 3 only

6. Under what conditions will the alveolar PACO2 rise above normal?

a.

If both metabolic rate and ventilation increase (e.g., through exercise)

b.

If carbon dioxide production decreases relative to VA

c.

If VA decreases relative to carbon dioxide production

d.

When the patient is febrile

If VA decreases relative to carbon dioxide production

7. A 70-kg male patient has a CO2 of 200 ml/min and a VA of 9 L/min. From this information, what can you infer?

a.

The patient's carbon dioxide production is abnormally low.

b.

The patient's A is abnormally low.

c.

The patient will have a lower than normal PACO2.

d.

The patient will have a higher than normal PACO2.

The patient will have a lower than normal PACO2.

8. What is the primary determinant of the PAO2?

a.

Body's CO2

b.

Metabolic rate of the body tissues

c.

PaO2

d.

PO2 in the inspired gas

PO2 in the inspired gas

9. The PAO2 depends on which of the following factors?

1. Ambient (atmospheric) pressure

2. Fractional concentration of inspired O2

3. Level of VA

4. Types of fuels burned (fat, protein, and carbohydrate)

a.

1, 2, and 3 only

b.

1 and 2 only

c.

3 only

d.

1, 2, 3, and 4

1, 2, 3, and 4

10. Calculate the approximate PAO2 given the following conditions (assume R = 0.8): FiO2 = .40, PB = 770 mm Hg, PACO2 = 31 mm Hg

a.

100 mm Hg

b.

135 mm Hg

c.

250 mm Hg

d.

723 mm Hg

250 mm Hg

11. A healthy person breathing 100% O2 at sea level would have PAO2 of approximately what level?

a.

149 mm Hg

b.

670 mm Hg

c.

713 mm Hg

d.

760 mm Hg

670 mm Hg

12. Which of the following best represents the partial pressures of all gases in the normally ventilated and perfused alveolus when breathing room air at sea level?

a.

PO2 = 40 mm Hg; PCO2 = 100 mm Hg; PN2 = 573 mm Hg; PH2O = 47 mm Hg

b.

PO2 = 100 mm Hg; PCO2 = 40 mm Hg; PN2 = 573 mm Hg; PH2O = 47 mm Hg

c.

PO2 = 100 mm Hg; PCO2 = 40 mm Hg; PN2 = 713 mm Hg; PH2O = 47 mm Hg

d.

PO2 = 149 mm Hg; PCO2 = 40 mm Hg; PN2 = 573 mm Hg; PH2O = 47 mm Hg

b.

PO2 = 100 mm Hg; PCO2 = 40 mm Hg; PN2 = 573 mm Hg; PH2O = 47 mm Hg

13. In a person breathing room air (and with all else being normal), if the alveolar PCO2 rises from 40 to 70 mm Hg, what would you expect?

a.

PAO2 to fall by approximately 30 mm Hg

b.

PAO2 to fall by approximately 40 mm Hg

c.

PAO2 to rise by approximately30 mm Hg

d.

PAO2 to rise by approximately 40 mm Hg

PAO2 to fall by approximately 30 mm Hg

14. Assuming a constant FiO2 and carbon dioxide production, which of the following statements is correct?

a.

An increased PACO2 will result in and increased PAO2.

b.

Increased FIO2 blows off carbon dioxide.

c.

Increases in alveolar ventilation (VA) decrease the PACO2 and increase the PAO2.

d.

The PAO2 varies proportionally with the PACO2.

Increases in alveolar ventilation (VA) decrease the PACO2 and increase the PAO2.

15. What is the highest PAO2 one could expect to observe in an individual breathing room air at sea level?

a.

90 to 100 mm Hg

b.

110 to 120 mm Hg

c.

640 to 670 mm Hg

d.

710 to 760 mm Hg

110 to 120 mm Hg

16. Which of the following conditions must exist for gas to move between the alveolus and pulmonary capillary?

a.

Adequate alveolar ventilation (VA)

b.

Difference in partial pressures (pressure gradient)

c.

Normal central nervous system (CNS) control mechanism

d.

Sufficient amount of blood hemoglobin (Hb)

Difference in partial pressures (pressure gradient)

17. Which of the following "layers" must be traversed by gases moving across the alveolar-capillary membrane?

1. Alveolar epithelial membrane

2. Capillary endothelial membrane

3. Interstitial space

4. Transbronchial radial tethering mechanisms

a.

1, 2, and 3 only

b.

1, 2, and 4 only

c.

2 and 3 only

d.

1, 2, 3, and 4

1, 2, and 3 only

18. When is the rate of gaseous diffusion across a biological membrane decreased?

a.

The diffusion distance is small.

b.

The gas diffusion constant increases.

c.

The partial pressure gradient is low.

d.

The surface area is large.

The partial pressure gradient is low.

19. Which of the following values corresponds most closely to the normal PO2 and PCO2 in the mixed venous blood returning to the lungs from the right side of the heart?

a.

PO2 = 40 mm Hg; PCO2 = 46 mm Hg

b.

PO2 = 40 mm Hg; PCO2 = 100 mm Hg

c.

PO2 = 100 mm Hg; PCO2 = 40 mm Hg

d.

PO2 = 100 mm Hg; PCO2 = 46 mm Hg

PO2 = 40 mm Hg; PCO2 = 46 mm Hg

20. Which of the following gases would diffuse fastest across the alveolar-capillary membrane?

a.

Air

b.

Carbon dioxide

c.

O2

d.

Nitrogen

Carbon dioxide

21. Carbon dioxide diffuses across the alveolar-capillary membrane approximately how many times faster than O2?

a.

10

b.

20

c.

30

d.

40

20

22. The time available for diffusion in the lung is mainly a function of which of the following?

a.

Functional residual capacity (FRC)

b.

Inspired O2 concentration

c.

Level of VA

d.

Rate of pulmonary blood flow

Rate of pulmonary blood flow

23. What is the minimum amount of time that blood must take for pulmonary capillary transit for equilibration of O2 to occur across the alveolar-capillary membrane?

a.

0.15 sec

b.

0.25 sec

c.

0.35 sec

d.

0.45 sec

0.25 sec

24. What is the primary factor that maintains the pressure gradient that drives O2 from the capillaries into the interstitial spaces and into the cells?

a.

Bohr effect on the RBC

b.

Cellular consumption of O2

c.

Haldane effect on the RBC

d.

Increased carbon dioxide in blood decreasing Hb affinity for O2

Cellular consumption of O2

25. In order to assess the events occurring at the tissue level, especially tissue oxygenation, what parameter would you sample and measure?

a.

Coronary sinus blood

b.

Left-sided heart blood

c.

Systemic arterial blood

d.

Systemic mixed venous blood

Systemic mixed venous blood

26. What is the normal range of PAO2 - PaO2 for healthy young adults breathing room air?

a.

5 to 10 mm Hg

b.

10 to 20 mm Hg

c.

20 to 30 mm Hg

d.

50 to 60 mm Hg

5 to 10 mm Hg

27. Breathing room air, a normal PAO2 - PaO2 of 5 to 10 mm Hg exists due to which of the following?

1. Anatomical shunts in the pulmonary and cardiac circulations

2. Normal limitations to O2 diffusion in the lung

3. Regional differences in pulmonary ventilation and blood flow

a. 1 and 3 only

b. 2 and 4 only

c. 1, 2, and 3

d. 1 and 2 only

1 and 3 only

28. Which of the following would you expect to occur if ventilation to an area of the lung remained constant but perfusion to this same area decreased?

1. The PACO2 should fall.

2. The PAO2 should fall.

3. The ratio V/Q should rise.

a.

3 only

b.

1 and 2 only

c.

1 and 3 only

d.

1, 2, and 3

1 and 3 only

29. Which of the following would you expect to occur if perfusion to an area of the lung remained constant, but VA to this same area decreased?

a.

The PACO2 should fall.

b.

The HCO3- will fall.

c.

The PAO2 should fall.

d.

The ventilation/perfusion ratio (V/Q) should rise.

The PAO2 should fall

30. An area of the lung has no blood flow but is normally ventilated. Which of the following statements are true about this area?

1. The alveolar gas is like air (PO2 = 150; PCO2 = 0).

2. The area represents alveolar dead space.

3. The / is elevated.

a.

1 and 2 only

b.

1 and 3 only

c.

2 and 3 only

d.

1, 2, and 3

1, 2, and 3

31. An area of the lung has no ventilation but is normally perfused by the pulmonary circulation. Which of the following statement(s) is/are correct?

1. Blood exiting the pulmonary capillary will have a PO2 = 40 and a PCO2 = 46.

2. The area represents an alveolar shunt.

3. The is 0.

a.

2 and 3 only

b.

1 and 3 only

c.

2 only

d.

1, 2, and 3

1, 2, and 3

32. Regarding pulmonary blood flow in the upright lung, which of the following statements is true?

a.

The apexes receive approximately 20 times more blood flow than the bases.

b.

The bases receive approximately 20 times more blood flow than the apexes.

c.

The greatest blood flow is found at the apexes of the lungs.

d.

The pulmonary circulation is a high-pressure system.

The bases receive approximately 20 times more blood flow than the apexes.

33. During normal inspiration, which of the following occurs?

a.

Alveoli at the apexes expand less than those at the bases.

b.

Alveoli at the apexes expand more than those at the bases.

c.

Alveoli at the bases and apexes expand almost equally.

d.

Alveoli at the bases expand less than those at the apexes.

Alveoli at the apexes expand less than those at the bases.

34. What occurs in the bases of the lung when a person is standing upright?

a.

The PAO2 is higher than normal.

b.

The respiratory exchange ratio is elevated.

c.

There is significant dead space under normal conditions.

d.

The V/Q is lower than the average.

The V/Q is lower than the average.

35. Even in healthy young subjects, regional differences in pulmonary ventilation and blood flow result in the PaO2 being lower than the PAO2. Why is this so?

a.

Most blood flows through the apexes of the lung.

b.

Most blood flows through areas with high V/Q.

c.

Most blood flows through the bases of the lung.

d.

Most ventilation goes to the apexes of the lung.

Most blood flows through the bases of the lung.

36. How is the vast majority of O2 carried in the blood?

a.

As bicarbonate ion (HCO3)

b.

As carbamino compounds

c.

Chemically combined with Hb

d.

In physical solution

Chemically combined with Hb

37. As the amount of O2 that dissolves in the plasma increases, what is it directly proportional to?

a.

Its partial pressure

b.

Its solubility coefficient

c.

Minute ventilation

d.

Temperature

Its partial pressure

38. At body temperature, how much O2 will physically dissolve in plasma at a PO2 of 40 mm Hg?

a.

0.12 ml/dl

b.

0.20 ml/dl

c.

0.30 ml/dl

d.

1.34 g/dl

0.12 ml/dl

39. Under normal physiologic circumstances, how many milliliters of O2 are capable of combining with 1 g of Hb?

a.

0.003 ml

b.

0.450 ml

c.

0.820 ml

d.

1.340 ml

1.340 ml

40. If the total hemoglobin content (Hb + HbO2) of a sample of blood is 20 g/dl and the oxyhemoglobin (HbO2) content is 15 g/dl, what is the HbO2 saturation?

a.

17%

b.

50%

c.

75%

d.

83%

75%

41. At a PaO2 of 65 mm Hg, what is the approximate saturation of Hb with O2?

a.

73%

b.

80%

c.

90%

d.

97%

90%

42. Why is it necessary to keep the patient's PaO2 greater than 60 mm Hg?

a.

A level of 60 mm Hg marks the beginning of the steep part of O2Hb dissociation curve.

b.

Below the 60 mm Hg level, tissue hypoxia is ensured.

c.

Oxygen deprivation will cause severe cerebral vasoconstriction below 60 mm Hg.

d.

The PaCO2 will start to rise precipitously if the PaO2 falls further.

A level of 60 mm Hg marks the beginning of the steep part of O2Hb dissociation curve.

51. What happens when the temperature of the blood rises?

1. The Hb saturation for a given PO2 falls.

2. The HbO2 curve shifts to the right.

3. The affinity of Hb for O2 increases.

a.

1 and 2 only

b.

1 and 3 only

c.

2 only

d.

1, 2, and 3

1 and 2 only

61. The largest percentage of carbon dioxide transported in the blood occurs as which of the following?

a.

Carbamino-Hb

b.

Carbonic acid (H2CO3)

c.

HCO3-

d.

Physically dissolved carbon dioxide

HCO3-

69. Hypoxia is best defined as a condition in which what occurs?

a.

Blood Hb levels are less than normal (15 g/dl).

b.

The arterial PCO2 is greater than normal (45 mm Hg).

c.

The arterial PO2 is greater than normal (100 mm Hg).

d.

Tissue O2 delivery is inadequate to meet cellular needs.

Tissue O2 delivery is inadequate to meet cellular needs.

70. Which of the following are potential causes of hypoxia?

1. Decrease in arterial PO2

2. Decrease in available Hb

3. Decrease in cardiac output

a.

1 and 2 only

b.

1 and 3 only

c.

2 and 3 only

d.

1, 2, and 3

1, 2, and 3

72. A patient breathing room air at sea level has the following arterial blood gases: PaO2 = 62 mm Hg; PCO2 = 75 mm Hg. When the FIO2 is raised to 0.28, the PaO2 rises to 95 mm Hg. What is the most likely cause of the hypoxemia?

a.

Hypoventilation

b.

Impaired diffusion

c.

Right-to-left shunt

d.

V/Q imbalance

Hypoventilation

73. What is the most common cause of hypoxemia in patients with lung disease?

a.

Diffusion defect

b.

Hypoventilation

c.

Right-to-left shunt

d.

V/Q mismatch

V/Q mismatch (ventilation perfusion

76. A patient with a normal PaO2 and cardiac output is exhibiting signs and symptoms of tissue hypoxia. What is the most likely cause?

a.

Hemoglobin deficiency

b.

Low ambient PO2

c.

Right-to-left shunt

d.

Hypoventilation

hemoglobin deficiency

77. What is the most important component in the O2 transport system?

a.

Dissolved O2 in ml/dl

b.

HCO3-

c.

Hb

d.

PaO2

Hb

88. Disorders that can lead to alveolar dead space include:

1. pulmonary emboli.

2. partial obstruction of the pulmonary vasculature.

3. destroyed pulmonary vasculature.

4. reduced cardiac output.

a.

1 and 2 only

b.

1 and 3 only

c.

1, 2, and 4 only

d.

1, 2, 3, and 4

1, 2, 3, and 4

87. The two major causes of dead space ventilation are:

1. a decreased tidal volume.

2. dysoxia.

3. impaired CO2 removal.

4. increased physiologic dead space.

a.

1 and 2 only

b.

1 and 3 only

c.

1 and 4 only

d.

1, 2, and 3 only

1 and 4 only

43. Given the following blood parameters, compute the total O2 content (dissolved + HbO2) of the blood in ml/dl: Hb = 18; PO2 = 40 mm Hg; SO2 = 73%.

a.

16.5 ml/dl

b.

17.7 ml/dl

c.

18.6 ml/dl

d.

19.5 ml/dl

17.7 ml/dl

44. Given the following blood parameters, compute the total O2 content (dissolved + HbO2) of the blood in ml/dl: Hb = 16; PO2 = 625 Hg; SO2 = 100%.

a.

17.8 ml/dl

b.

19.4 ml/dl

c.

21.4 ml/dl

d.

23.3 ml/dl

23.3 ml/dl

45. What is the approximate normal CaO2 - CO2 in a healthy adult at rest?

a.

5 ml/dl

b.

15 ml/dl

c.

20 ml/dl

d.

250 ml/dl

5 ml/dl

46. A patient has a whole-body O2 consumption of 320 ml/min and a measured CaO2 - CO2 of 8 ml/dl. What is the cardiac output?

a.

3.2 L/min

b.

4.0 L/min

c.

5.0 L/min

d.

7.0 L/min

4.0 L/min

47. According to the Fick principle, if O2 consumption remains constant, an increase in cardiac output will manifest itself as which of the following?

a.

Decrease in the CaO2 - CO2.

b.

Increase in the CaO2.

c.

Increase in the CaO2 - CO2.

d.

Decrease in the CO2.

Decrease in the CaO2 - CO2.

48. According to the Bohr effect, when the pH drops, what happens?

1. The affinity of Hb for O2 decreases.

2. The Hb saturation for a given PO2 falls.

3. The Hb saturation for a given PO2 rises.

a.

1 and 2 only

b.

2 only

c.

2 and 3 only

d.

1, 2, and 3

1 and 2 only

49. Compared to normal levels, a shift in the HbO2 curve to the right has which of the following effects?

1. The affinity of Hb for O2 decreases.

2. The Hb saturation for a given PO2 falls.

3. The Hb saturation for a given PO2 rises.

a.

1 only

b.

1 and 2 only

c.

2 and 3 only

d.

1, 2, and 3

1 and 2 only

50. What role does the Bohr effect play in O2 transport?

a.

Describes the effect of varying enzyme levels on Hb and O2 affinity.

b.

Diminishes tissue oxygenation due to electrolyte imbalances.

c.

Enhances O2 delivery to tissues and O2 pickup at lungs.

d.

Explains the effect that O2 levels have on carbon dioxide transport.

Enhances O2 delivery to tissues and O2 pickup at lungs.

52. What is the effect of an elevated intracellular 2,3-DPG concentration?

a.

Decreases the availability of O2 to the tissues.

b.

Increases the affinity of Hb for O2.

c.

Increases the availability of O2 to the tissues.

d.

Shifts the HbO2 dissociation curve to the left.

Increases the availability of O2 to the tissues.

53. In which of the following conditions will erythrocyte concentration of 2,3-DPG be decreased?

a.

Anemia

b.

Banked blood

c.

High pH

d.

Hypoxemia

Banked blood

54. The oxidation of the Hb molecule's iron ions to the ferric state (Fe3+) results in which of the following?

1. Form of anemia called sickle cell anemia

2. Formation of methemoglobin (metHb)

3. Inability of metHb to bind with O2

a.

1 and 2 only

b.

1 and 3 only

c.

2 and 3 only

d.

1, 2, and 3

2 and 3 only

55. The affinity of Hb for carbon monoxide (CO) is approximately how many times greater than its affinity for O2?

a.

10 to 50 times greater

b.

50 to 90 times greater

c.

100 to 190 times greater

d.

200 or greater

200 or greater

56. Which of the following increases the affinity of Hb for O2?

1. Decreased 2,3-DPG

2. Decreased PCO2

3. Increased pH

4. Increased temperature

a.

1, 2, and 3 only

b.

1, 2, and 4 only

c.

3 and 4 only

d.

3 and 4 only

1, 2, and 4 only

57. Which of the following is true regarding fetal hemoglobin (HbF)?

a.

It has a reduced level of 2,3-DPG.

b.

It is replaced in the first month of life.

c.

It delivers more O2 to tissues at low PaO2 than normal Hb.

d.

It has a higher P50 than normal Hb.

It delivers more O2 to tissues at low PaO2 than normal Hb.

58. A patient has a P50 value of 29 mm Hg. What does this indicate?

a.

Decreased affinity of Hb for O2

b.

Higher than normal Hb saturation for a given PO2

c.

Increased affinity of Hb for O2

d.

Normal position in the HbO2

Decreased affinity of Hb for O2

59. In which of the following forms is/are carbon dioxide transported by the blood?

1. Chemically combined with proteins

2. Ionized as bicarbonate (HCO3-)

3. Simple physical solution

a.

2 only

b.

3 only

c.

2 and 3 only

d.

1, 2, and 3

1, 2, and 3

60. Which of these statements applies to the following reaction: Prot-NH2 + CO2 Prot-NHCOO- + H+?

a.

Approximately 20% of the total blood carbon dioxide is carried in this form.

b.

It is second in importance to only the bicarbonate buffer system.

c.

It represents the formation of blood carbamino compounds.

d.

The resulting H+ ions are buffered by reduced HCO3.

It represents the formation of blood carbamino compounds.

62. Why is the presence of carbonic anhydrase in RBCs so crucial for carbon dioxide transport?

a.

Forms H2CO3, which is the major buffer for carbon dioxide.

b.

Drives the hydrolysis reaction that forms HCO3-.

c.

Forms H2CO3, which is the way the majority of carbon dioxide is transported.

d.

Without its formation, carbon dioxide could not be excreted at the lungs.

Drives the hydrolysis reaction that forms HCO3-.

63. When a Hb molecule accumulates excessive amounts of HCO3-, it is expelled from the cell in exchange for Cl-. What is this called?

a.

Bohr effect

b.

Haldane effect

c.

Hamburger phenomenon

d.

Hydrolysis phenomenon

Hamburger phenomenon

64. When Hb saturation with O2 is high, less carbon dioxide is carried in the blood. What is this relationship called?

a.

Bohr effect

b.

Chloride shift

c.

Dissociation constant

d.

Haldane effect

Haldane effect

65. The conversion of HbO2 to deoxygenated Hb does which of the following?

1. Decreases blood carbon dioxide content.

2. Enhances carbon dioxide loading on Hb.

3. Helps buffer H+ ions.

a.

2 and 3 only

b.

1 and 2 only

c.

3 only

d.

1, 2, and 3

2 and 3 only

66. Which of the following statements is true regarding the Haldane effect?

a.

At high SaO2 levels, carbon dioxide more readily forms carbamino compounds.

b.

At high SaO2 levels, the capacity of blood to hold carbon dioxide decreases.

c.

At high SaO2 levels, the capacity of blood to hold carbon dioxide increases.

d.

At low SaO2 levels, the capacity of blood to hold carbon dioxide decreases.

At high SaO2 levels, the capacity of blood to hold carbon dioxide decreases.

67. Which of the following equations best describes O2 delivery to the tissues?

a.

Arterial O2 content ÷ cardiac output

b.

Arterial O2 content × cardiac output

c.

Cardiac output + arterial O2 content

d.

Cardiac output × vascular resistance

Arterial O2 content × cardiac output

68. In the presence of an acutely reduced arterial O2 content (hypoxemia), normal O2 delivery to the tissues can be maintained by which of the following?

a.

Hyperventilation (increased VA)

b.

Increased RBC production

c.

Increasing the cardiac output

d.

Peripheral vasoconstriction

Increasing the cardiac output

71. An abnormal metabolic state in which the tissues are unable to utilize the O2 made available to them best describes which of the following?

a.

Diffusion hypoxia

b.

Dysoxia

c.

Hemic hypoxia

d.

Physiologic shunt

Dysoxia

74. A patient breathing 40% O2 at sea level has a PaO2 of 50 mm Hg, a PCO2 of 30 mm Hg, and a PAO2 - PaO2 of 250 mm Hg. When the FiO2 is raised to 0.7, the PaO2 rises to only 58 mm Hg. Hypoxemia is primarily due to which of the following?

a.

Hypoventilation

b.

Impaired diffusion

c.

Right-to-left shunt

d.

V/Q imbalance

Right-to-left shunt

75. The expected PaO2 for an 80-year-old man who is otherwise in good health and breathing room air is approximately what level?

a.

50 mm Hg

b.

75 mm Hg

c.

80 mm Hg

d.

90 mm Hg

75 mm Hg

78. When O2 uptake by the tissues is abnormally low, as occurs in certain forms of dysoxia, what would you expect to find?

a.

Decreased CaO2

b.

Decreased CvO2

c.

Decreased PaO2

d.

Increased CvO2

Increased CvO2

79. Which of the following would you expect to find with "O2 debt"?

1. Accentuated in diseases such as sepsis.

2. O2 demand exceeds O2 delivery.

3. O2 excess usage results in debt.

a.

1, 2, and 3

b.

1 and 2 only

c.

2 only

d.

2 and 3 only

1 and 2 only

80. Under which of the following conditions may carbon dioxide removal be impaired?

1. When a V/Q mismatch exists.

2. When the dead space ventilation/min is increased.

3. When the minute ventilation is inadequate.

a.

1 and 2 only

b.

1 and 3 only

c.

2 and 3 only

d.

1, 2, and 3

1, 2, and 3

81. What can you assume about a patient who has a V/Q mismatch and exhibits hypercapnia?

a.

The central nervous system is not responding to the increased PCO2.

b.

The patient cannot sustain the high E to overcome the high VD.

c.

The patient is compensating for an acute metabolic alkalosis.

d.

The patient is compensating for a chronic metabolic acidosis.

The patient cannot sustain the high E to overcome the high VD.

82. What does / mismatch have the biggest impact on?

a.

Carbon dioxide elimination

b.

Dissolved HCO3-

c.

Oxygenation

d.

pH

Oxygenation

83. If blood from an area of the lung with a high / is mixed with blood perfusing an area with a low V/Q , what will be the result?

a.

CaO2 higher than the average of the two

b.

CaO2 lower than the average of the two

c.

PaO2 equal to the average of the two

d.

PaO2 lower than the average of the two

PaO2 lower than the average of the two

85. Under which of the following conditions can the alveolar partial pressure of carbon dioxide (PACO2) be increased?

1. When the body increases its production of CO2 (VCO2)

2. When the dead space ventilation per minute is increased (VD)

3. When the minute ventilation is inadequate (VE)

4. When the alveolar ventilation is decreased (VA)

a.

1 and 2 only

b.

1 and 3 only

c.

1, 2 and 3

d.

1, 2, 3, and 4

1, 2, 3, and 4

86. When using therapeutic agents that can cause methemoglobinemia (methHb), which of the following is important to prevent adverse effects?

a.

Checking the frequency of ventilation

b.

Frequent monitoring for methHb to weigh the risk against the benefit

c.

Occasional monitoring for sickle cell anemia

d.

Frequent monitoring for abnormal body temperature (high or low)

Frequent monitoring for methHb to weigh the risk against the benefit

84. Which of the following statements is NOT true about the effect of / imbalances on O2 and carbon dioxide exchange?

a.

Blood leaving high V/Q units has a high PO2 and a low PCO2.

b.

Blood leaving low V/Q units has a low PO2 and a high PCO2.

c.

High V/Q units can compensate for high PCO2 levels from low V/Q units.

d.

High V/Q units can compensate for low PO2 levels from low V/Q units.

High V/Q units can compensate for low PO2 levels from low V/Q units.