Chapter 16: Blood Gases, Pulse Oximetry and Capnography

Question 1

moves air in and out of the alveolus for gas exchange

Answer 1

tidal volume

Question 2

movement of air through large airways and non perfused areas of lung

Answer 2

physiologic dead space

Question 3

physiologic dead space is approximately ____ of the tidal volume

Answer 3

30%

Question 4

called the air remaining inside the chest at the end of exhalation

Answer 4

functional residual capacity

Question 5

product of the respiratory rate and tidal volume

Answer 5

minute ventilation

Question 6

Positive-pressure ventilation increases the functional residual capacity through

Answer 6

recruitment of collapsed nonventi- lated alveolar space

Question 7

percentage of oxygen in each breath

Answer 7

FiO2

Question 8

Each liter per minute of oxygen flow delivered via nasal cannula increases the Fio2 by about ___

Answer 8

4%

Question 9

The expected Pao2 from supplemental oxygen can be roughly estimated by

Answer 9

multiplying the actual Fio2 by 5, the Five Times Rule

Question 10

For every 1000-ft (305-m) rise in altitude, the atmospheric partial pressure of oxygen (Po2) drops about

Answer 10

5 mm Hg

Question 11

3 factors that determine the diffusion efficiency

Answer 11

1. interstitial space
2. partial pressure of the gas in the alveolar space
3. solubility of the gas

Question 12

T or F: An arterial blood sample is the reference standard for pH, oxygen,
carbon dioxide, and lactate content

Answer 12

True

Question 13

The ideal sampling site for a systemic venous sample is at ____

Answer 13

the pulmonary artery

Question 14

pH in venous compared to pH in artery

Answer 14

(+/– 0.05 pH units)

Question 15

Venous carbon dioxide values trend along with arterial carbon dioxide, although they vary somewhat

Answer 15

(up to +/– 20 mm Hg)

Question 16

T or F:

venous Pao2 values do not correlate with arterial oxygen content and cannot be used for evaluation of oxygenation.

Answer 16

True

Question 17

Pulse oxygenation values greater than ____ are highly predictive of arterial saturations greater than 90%

Answer 17

92%