Ch. 3 Pilbeams Flashcards
What is the trigger variable?
Begins inspiration
What is the limit variable?
Limits the value of pressure, flow, or time during inspiration.
What is the cycle variable?
Ends inspiration
What is time triggering?
Vent initiates the breath after a set time
What is pt triggering?
Patient can start the breath (trigger).
What are the most common triggering variables?
Pressure and flow
Time triggering?
Drivers a breath after a set time has elapsed
What is the control mode (locked out)?
When the pt is apneic, sedated, or paralyzed and makes no effort to breathe
Inspiration begins if a_______________ or __________ is detected.
Negative airway opening pressure ; change in flow
What is the sensitivity setting also called?
Patient effort or pt triggering
The sensitively level for pressure triggering is usually set at?
-1cmH20
If the ventilator is too sensitive it can cause what?
Auto-triggering (machine takes a breath without the pt making an effort).
Flow triggering?
Occurs when the ventilator detects a drop in flow through the patient circuit during exhalation.
When set properly flow triggering has been shown to _______ ?
Require less WOB or triggering
Volume triggering?
Occurs when the vent detects a small drop in volume in the pt circuit during exhalation.
Manual triggering?
Breath is initiated by pressing a button on the machine
What is assist control mode?
When the rate control determines the minimum number of mechanical breaths delivered, the patient has the option of breathing at a faster rate.
Pressure limiting?
Allows pressure to rise to a certain value but not exceed it
When the vent reaches the________, excess pressure is vented through the spring loaded pressure release, or ______?
High-pressure limit ; pop-off
What are some other examples of pressure limiting modes?
Pressure support and pressure controlled ventilation
Volume limiting?
is controlled by an electronically operated valve that measures the flow passing through the ventilator circuit during a specific interval.
With volume limiting the vent may include…?
A bag, bellows, or piston cylinder that contains a fixed volume, which establishes the maximum volume of gas that can be delivered.
Flow limiting?
If gas flow from the ventilator to the patient reaches but does not exceed a maximum value before the end of inspiration, the ventilator is flow limited; that is, only a certain amount of flow can be provided.
What is maximum safety pressure?
When ventilators allows inspiratory pressure to reach but not exceed a maximum pressure. This maximum safety pressure is used to prevent excessive pressure from damaging a patient’s lungs.
What is the value for maximum safety pressure?
10 cmH2O above the average peak inspiratory pressure.
What is the variable the the vent used to end inspiration?
Cycle mechanism
What are the 4 factors that can end inspiration?
Volume, flow, time, pressure
Volume cycled ventilation?
Is terminated when the set volume has been delivered.