The volume delivered by a pressure-limited ventilator will ...

[viki]

The volume delivered by a pressure-limited ventilator will decrease under which of the following conditions?
 
  1. The patient's lung or thoracic (chest wall) compliance falls.
  2. Airway resistance rises (inspiratory time <3 times the time constant).
  3. The patient tenses the respiratory muscles during inspiration.
  4. Airway resistance rises (inspiratory time >3 times the time constant).
  a. 1 and 3 only
  b. 1, 3, and 4 only
  c. 3 and 4 only
  d. 2, 3, and 4 only

Question 2

Which of the following occur in pressure-limited modes of ventilation?
 
  1. The volume delivered at a given pressure must decrease as compliance falls.
  2. The inspiratory flow varies with patient effort and lung mechanics.
  3. Active effort by the patient against inspiration will decrease delivered volume.
  4. The volume delivered at a given pressure must increase as Raw rises.
  a. 1 and 3 only
  b. 1, 2, and 3 only
  c. 3 and 4 only
  d. 2, 3, and 4 only

[aburgess]

Answer to Question 1

ANS: B
However, if insufficient time is available for pressure equilibration, delivered volume decreases as airway resistance increases.

Answer to Question 2

ANS: B
An increase in resistance, active exhalation, or muscle tensing by the patient during inspiration also decreases delivered volume in pressure ventilation.

[viki]

Thanks for the timely response, appreciate it

[xiazhe]

Wow, this really help