An increase in airway resistance during pressure ventilation will ...

[humphriesbr@me.com]

An increase in airway resistance during pressure ventilation will result in which of the following?
 
  a. Plateau pressure (PPlateau) will increase.
  b. Volume curve will resemble an igloo.
  c. Inspiration will end prior to flow tapering to zero.
  d. Pressure curve will become concave on inspiration.

Question 2

Delayed termination during pressure support ventilation (PSV) can be avoided with patients who have chronic obstructive pulmonary disease (COPD) by doing which of the following?
 
  a. Increase inspiratory time
  b. Increase flow-cycle percent
  c. Change the flow pattern
  d. Decrease peak inspiratory pressure

[Danny Ewald]

Answer to Question 1

ANS: C
With increased airway resistance the flow-time scalar will show a curve that is flatter in appear-ance. Flow will not drop to zero by the time the set inspiratory time is reached. Consequently, the ventilator and lung pressures do not equilibrate and this can affect the overall volume delivered to the patient.

Answer to Question 2

ANS: B
The presence of active exhalation during pressure support ventilation (PSV) indicates that the patient is trying to end the breath early. This is referred to as delayed termination and is associ-ated with patient-ventilator asynchrony. This phenomenon is often seen with patients who have increased airway resistance, as in chronic obstructive pulmonary disease (COPD). Since inspira-tory time is determined by flow cycling in PSV, increasing the flow-cycle setting will shorten inspiration, allowing more time for exhalation.