Deck 8: Ventilation-Perfusion Relationships

Question 1

Under normal circumstances, what volume of oxygen is consumed by the tissues during one minute of internal respiration?

A) 150 mL
B) 250 mL
C) 200 mL
D) 400 mL

Answer 1

B

Question 2

What is the term for the quantity of oxygen and carbon dioxide exchanged in one minute during external respiration?

A) respiratory exchange ratio
B) ventilation perfusion ratio
C) end tidal CO2: O2
D) respiratory quotient

Answer 2

A

Question 3

Following emergency endotracheal intubation, what would an ETCO2 of zero indicate?

A) right mainstem placement
B) left mainstem placement
C) correct endotracheal placement
D) esophageal tube placement

Answer 3

D

Question 4

What effect does a reduced ventilation perfusion ratio have on end-capillary PO2 and PCO2?

A) end capillary PO2 will decrease and end capillary PCO2 will increase
B) end capillary PO2 will increase and end capillary PCO2 will decrease
C) end capillary PO2 and PCO2 will both decrease
D) end capillary PO2 will decrease while end capillary PCO2 will remain constant

Question 5

What effect would upper airway obstruction have on ventilation-perfusion ratio, PAO2 and PACO2?

A) The V/Q ratio and PACO2 will decrease and PAO2 will increase.
B) The V/Q ratio and PAO2 will decrease and PACO2 will increase.
C) The V/Q ratio and PAO2 will increase and PACO2 will decrease.
D) The V/Q ratio and PACO2 will increase and PAO2 will decrease.

Question 6

Which of the following statements are true regarding a capnogram? ?
I. It is a direct measurement of PCO₂ eliminated by the lungs.
II. It is an indirect measurement of PCO₂ eliminated by the lungs.
III. It is an indirect measurement of PvCO₂.
IV. It is a direct measurement of PaCO₂.

A) II and IV only
B) II and III only
C) I and III only
D) I and IV only

Question 7

What would the ventilation-perfusion ratio equal if the pulmonary blood flow is 5.4 L/min and the alveolar tidal volume is 350 mL, and the respiratory rate is 12/min?

A) 0.54
B) 0.85
C) 0.66
D) 0.78

Question 8

What can cause an increased ventilation-perfusion ratio to develop? ?
I. increase in ventilation
II. decrease in ventilation
III. decrease in perfusion
IV. increase in perfusion

A) I and IV only
B) II and IV only
C) I only
D) I and III only

Question 9

Which of the following conditions would result in an increased ETCO₂?
I. Seizures
II. Hyperthermia
III. Hemorrhage
IV. Pulmonary emboli

A) I and III only
B) II, III, and IV only
C) I and II only
D) I, II, and III only

Question 10

What would the RQ equal if the volume of CO2 produced was 220 mL/min and the volume of O2 consumed was 300 mL/min?

A) 0.73
B) 0.88
C) 0.66
D) 1.36

Question 11

What would the ventilation-perfusion ratio equal if pulmonary capillary blood flow equals 4 L/min and the minute alveolar ventilation equals 5 L/min?

A) 1.25
B) 0.66
C) 1.0
D) 0.8

Question 12

Which of the following will result in a decreased ventilation-perfusion ratio?
I. Asthma
II. Emphysema
III. Pulmonary fibrosis
IV. Pulmonary emboli

A) I, II, and III only
B) I, II, and IV only
C) 1, II, III, and IV
D) II, III, and IV only

Question 13

Which of the following conditions would result in an increased ventilation-perfusion ratio?
I. Pulmonary emboli
II. Pulmonary Hypertension
III. Pneumothorax
IV. Cardiac arrest

A) II, III, and IV only
B) I. II, and III only
C) I, II, III, IV
D) I, and III only

Question 14

In the upright position, which region of the right lung would have the lowest ventilation-perfusion ratio?

A) middle lobe
B) lower lobe
C) hilum
D) upper lobe

Question 15

Which waveform on a capnogram is characteristic of bronchospasm that occurs during a severe asthmatic episode?

A) shark-fin
B) square wave
C) sawtooth
D) sine wave

Question 16

When a decreased ventilation-perfusion ratio occurs, which of the following changes will occur? ?
I. PAO₂ will increase
II. PAO₂ will decrease
III. PACO₂ will increase
IV. PACO₂ will decrease
V. pH will decrease

A) 1, III, and V only
B) II ,III, and V only
C) II and IV only
D) I, IV, and V only

Question 17

What is the normal value for ETCO2 in a healthy young adult?

A) 5%
B) 8%
C) 15%
D) 18%

Question 18

What is the term for the relationship between alveolar ventilation and pulmonary capillary blood flow?

A) respiratory rate
B) respiratory exchange ratio
C) ventilation-perfusion ratio
D) respiratory quotient

Question 19

What does the overall ventilation perfusion ratio equal in a healthy adult?

A) 0.8
B) 0.25
C) 0.4
D) 0.6

Question 20

What changes would be expected in the ventilation-perfusion ratio in the presence of excessive blood loss?

A) The ventilation-perfusion ratio initially decreases will increase then will decrease dramatically.
B) The ventilation-perfusion ratio will increase.
C) The ventilation-perfusion ratio will decrease.
D) The ventilation-perfusion ratio will remain constant.