Mechanical Ventilation Flashcards
What is volume pre-set assist control ventilation?
A mode in which the operator sets a tidal volume and a minimum ventilatory rate, where both the patient and the ventilator are able to initiate breaths.
What are the advantages of volume pre-set assist control ventilation?
Simple to set
Guaranteed minute ventilation
Rests muscles of respiration
What are the disadvantages of volume pre-set assist control ventilation?
Not synchronised with patient’s breathing
Inappropriate triggering (e.g. as a result of hiccoughs) can result in excessive minute ventilation
Fall in lung compliance results in high alveolar pressure and barotrauma
What is pressure pre-set assist control ventilation?
A constant pressure is applied during inspiration.
This results in a high initial flow until the pressure is reached, at which point the flow slows and stops.
What is the advantage of pressure pre-set assist control ventilation?
Oxygenation may be better due to the flow pattern (initial high rate of flow)
Avoids high inspiratory pressures.
What are the disadvantages of pressure pre-set assist control ventilation?
Not synchronised with the patient’s breathing.
Inappropriate triggering (e.g. due to hiccoughs) can result in excessive minute ventilation.
Change in lung compliance can result in a change in tidal volume.