During a single-breath capnogram, what does the occurrence of a ...

[waynest]

During a single-breath capnogram, what does the occurrence of a plateau indicate?
 
  a. Exhalation of mainly dead space gas
  b. Inspiration of fresh respiratory gas
  c. Exhalation of mixed alveolar and dead space gas
  d. Exhalation of mainly alveolar gas

Question 2

At the very beginning of exhalation, the PETCO2 normally should be at what level?
 
  a. 0 mm Hg
  b. 15 mm Hg
  c. 25 mm Hg
  d. 40 mm Hg

[nital]

Answer to Question 1

ANS: D
This plateau indicates exhalation of gas coming mainly from ventilated alveoli.

Answer to Question 2

ANS: A
Initially, the expired PCO2 is 0 mm Hg, indicating exhalation of pure dead space gas.