Ventilators nowadays in common use are:
|A||Volume preset, time cycled|
|B||Pressure preset, time cycled|
|C||Pressure preset, flow cycled|
|D||Volume preset, flow cycled|
Volume preset, time cycled
Ventilators are of two types:
1. Volume preset and time cycled.
2. Pressure preset and flow cycled.
Pressure preset type ventilators deliver tidal volume only after preset pressure is reached so if airway pressure increases the patient can be severely hypoventilated that is why these ventilators are out of use. Volume preset type ventilators will deliver preset tidal volume at fix interval.