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.

Rate

We can decide how often we give the patient a breath each minute.

Flow rate

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.

FiO2

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?