The pressure-versus-time curve in the figure represents which of ...

[burchfield96]

The pressure-versus-time curve in the figure represents which of the following ventilator modes?
 
  a. Airway pressure-release ventilation
  b. Pressure-support ventilation with contin-uous positive airway pressure
  c. Pressure-controlled intermittent mandato-ry ventilation plus pressure support
  d. Volume-controlled intermittent mandatory ventilation plus pressure support

Question 2

What is the inspiratory time-to-expiratory time ratio for the following ventilator settings: a minute volume of 8 L/min, a respiratory rate of 10 breaths/min, and a flow rate of 40 L/min?
 
  a. 1:2 c. 1:4
  b. 1:3 d. 1:5

[katieost]

Answer to Question 1

ANS: A
Airway pressure-release ventilation provides two levels of continuous positive airway pressure while allowing the patient to breathe spontaneously at both continuous positive airway pressure levels. The sine waveforms at both continuous positive airway pressure levels represent the spon-taneous breathing of the patient. The higher continuous positive airway pressure level is usually held longer than the lower continuous positive airway pressure levelhence the term airway pressure release.

Answer to Question 2

ANS: C
40 L/min = 40  60 L/s = 0.67 L/s. Tidal volume = VE  f = 8 L/min  10 = 0.8 L. Inspiratory time = Tidal volume (in liters)  Flow rate (in liters/second) = 0.8 L  0.67 L/s = 1.19 s.

[burchfield96]

Excellent

[shewald78]

TYSM