During which phase of a capnograph does alveolar gas containing ...

[aabwk4]

During which phase of a capnograph does alveolar gas containing carbon dioxide (CO2) mix with gas from the anatomical airways and the CO2 concentration rises?
 
  a. Phase 1
  b. Phase 2
  c. Phase 3
  d. Phase 4

Question 2

An arterial blood gas should be done to confirm pulse oximetry findings less than a minimum of _____________.
 
  a. 60
  b. 70
  c. 80
  d. 90

[hollysheppard095]

Answer to Question 1

ANS: B
In phase 1, the initial gas exhaled is from the conducting airways, which contain low levels of carbon dioxide (CO2) from inspired air. During phase 2, alveolar gas containing CO2 mixes with gas from the anatomical airways and the CO2 concentration rises. In phase 3, the curve plateaus as alveolar gas is exhaled. In phase 4, the concentration falls to zero.

Answer to Question 2

ANS: C
When a patient's oxygen saturation measured by pulse oximeter (SpO2) is less than 80 an arteri-al blood gas should be drawn to confirm the patient's oxygenation status because a pulse oxime-ter is generally accurate for oxygen saturations greater than 80.