PAV Flashcards
What is PAV
A mode designed to assist with spontaneous ventilation, the breath that is delivered is similar to PS but the pressure support level is variable and proportional to spontaneous effort
The harder the patient works, the more support the ventilator delivers =POSITIVE-FEEDBACK!
The less the patient works, the less support is provided
PAV Phase Varaibles
Trigger: patient only!
Limit: pressure-limited
Cycle: flow
Assistance in PAV can be Provided in the Form of
Flow-proportional assist- To help overcome WOB due to resistance
Volume-proportional assist-To help overcome WOB due to elastance (1/C)
Who is PAV Best Suitable for
Best suited for patient’s with abnormalities in resistance and compliance
Who is PAV not suited for
Not suitable for patient’s with neuromuscular weakness or CNS depression who cannot generate an adequate inspiratory effort
Low patient effort means low vent support!
PAV Vs. PS
They are very similar but PAV is more intelligent and adaptive to the patient’s inspiratory efforts
Physiologically PAV will decrease the WOB but Palv has to be slightly negative throughout inspiration making it more physiologically similar to spontaneous breathing
PAV Settings
Will vary depending on the ventilator
PEEP
FiO2
Sensitivity
% Support
% Support
If set at 50% of patient’s elastance and 50% of patient’s resistance the ventilator will provide half the work to overcome each the forces of elastance and resistance.
If the patient makes no effort, the vent does no work.
Understanding the WOB graph
