Volume controlled ventilation
We can put a certain volume of air into the patient with each breath in mechanical ventilation.
Pressure controlled ventilation
We can put air into the patient until the pressure reaches a certain value.
We can decide how often we give the patient a breath each minute.
For example, we can give a certain volume of gas , but the flow rate will determine whether we give that volume slowly or quickly over that breath.
In other words, the oxygen concentration we give to the patient, from 21% (room air) to 100%.
What triggers the breath?
Do we have the patient decide when they want to breathe, or do we have the ventilator decide when to initiate a breath? Or indeed a combination of the two? Is it ventilator controlled or patient controlled?