Author Question: The volume of gas actually delivered to a patient by most positive-pressure ventilation is always ... (Read 35 times)

cmoore54 · **on:** Jul 16, 2018

The volume of gas actually delivered to a patient by most positive-pressure ventilation is always less than that expelled from the machine. Which of the following factors help to explain this finding?

1. Gas compression under pressure
2. Presence of built-in leaks
3. Expansion of the ventilator circuitry
a. 2 and 3 only
b. 1 and 2 only
c. 1, 2, and 3
d. 1 and 3 only

Question 2

Inspection of the airway pressure waveform of a patient receiving volume-controlled continuous mandatory ventilation assist-control with constant flow reveals a large dip or drop in pressure at the beginning of inspiration.

Which of the following problems is most likely?
a. The trigger setting is improper.
b. The inspiratory flow is inadequate.
c. The set volume is too large.
d. The pressure limit is too low.

lucas dlamini · **Reply #1 on:** Jul 16, 2018

Answer to Question 1

ANS: D
First, gases are compressed when delivered under pressure. Thus, the generated volume (at at-mospheric pressure) occupies less space when delivered under pressure. Second, most ventilator circuits are somewhat compliant.

Answer to Question 2

ANS: A
At the beginning of inspiration, a small negative deflection on the manometer suggests an appro-priate sensitivity setting.