Patient Ventilator Interaction Flashcards
What are the general types of asynchrony?
Flow asynchrony
trigger asynchrony
cycle asynchrony
and mode asynchrony
Asynchrony can be caused by what?
It can be caused by inappropriately set sensitivity, PEEP, flow, tidal volume, and inspiratory time
Flow asynchrony is a result of what?
The flow provided by the ventilator being inadequate to match the patient’s inspiratory demand
Trigger asynchrony can manifest as what?
Missed triggering, delayed triggering, auto-triggering, double triggering, and reverse triggering
Missed triggering and delayed triggering are normally a result of what?
Auto-PEEP
Auto-triggering is normally a result of what?
Circuit leaks
Water in the circuit
Inappropriately set sensitivity
and Hyperdynamic cardiac contractions
Flow asynchrony is a result of what?
A result of the ventilator providing less flow then the patient’s respiratory center requires
Why can volume ventilation be expected to cause the most asynchrony?
Because it controls volume, flow, and time
What causes Trigger Delay?
Auto-PEEP, Poor Sensitivity Setting, and Ventilatory Malfunction
How can a Trigger Delay be modified?
Minimizing Auto-Peep, Apply PEEP, Decrease minute volume/tidal volume, Appropriately set sensitivity, or you may need to replace the ventilator
How can Auto-triggering be modified?
New ventilator circuit, Removal of water from the circuit, and Appropriate setting of sensitivity
What causes Double Triggering?
Inadequate tidal volume, short inspiratory time, and an inappropriate mode of ventilation
How can Double Triggering be modified?
Increase tidal volume (<8ml/kg PBW), Increase inspiratory time to match patient’s inspiratory time, and Mode changed to pressure support
What causes missed triggering?
Dynamic airway obstruction and
Delivery of excessive minute ventilation/tidal volume
What causes Reverse Triggering?
Controlled breath and Expiratory phase
