Which of the following values of VD/VT, are suitable for weaning? ...

[Mollykgkg]

Which of the following values of VD/VT, are suitable for weaning? 1. 0.10 2. 0.20 3. 0.30 4. 0.60
 
  a. 1 and 3 only
  b. 1, 2, and 3 only
  c. 3 and 4 only
  d. 2, 3, and 4 only

Question 2

What is the best single measure of effective ventilation in the intensive care unit patient?
 
  a. Dead space-tidal volume ratio
  b. PaCO2
  c. End-tidal PCO2
  d. Qs/Qt

[zhanghao]

Answer to Question 1

ANS: B
A VD/VT ratio greater than 0.60 is predictive of lack of success at discontinuance of ventilation.

Answer to Question 2

ANS: B
Because of the relationship between alveolar ventilation and PaCO2, the single best index of ef-fective ventilation is measurement of the PaCO2.