The baseline pressure on a mechanical ventilator operating in the ...

[crazycityslicker]

The baseline pressure on a mechanical ventilator operating in the ICU has been changed from 8 cm H2O to 12 cm H2O. The trigger sensitivity had been set, and remains at 2 cm H2O. To what pressure will the circuit pressure have to decrease for inspiration to be pressure triggered?
 
  A. 2 cm H2O
  B. 6 cm H2O
  C. 10 cm H2O
  D. 14 cm H2O

Question 2

Which of the following terms are phase variables? I. inspiration II. flow III. cycle IV. trigger
 
  A. I, II only
  B. III, IV only
  C. I, III only
  D. II, IV only

[moormoney]

Answer to Question 1

ANS: C

Answer to Question 2

ANS: BI. Incorrect response: Inspiration and exhalation are phases of the respiratory cycle, not phase variables.
II. Incorrect response: Flow is not a phase variable.
III. Correct response: Cycle and trigger are referred to as phase variables in the context described below. Every breath has four phases: (1) the change from exhalation to inspiration (trigger), (2) the variable that reaches a plateau before the end of inspiration, but is not responsible for terminating inspiration (limit), (3) the change from inspiration to exhalation (cycle), and (4) baseline (i.e., PEEP).
IV. Correct response: The term trigger applies to the phase variable that causes inspiration to begin. Inspiration can be either pressure, volume, flow, or time triggered.