Describe Pressure Controlled Ventilation (PCV)
This is a pressure cycled mode (machine delivers a set pressure - the tidal volume generated depends on how compliant the lungs are) that is completely controlled by the ventilator. Because of a characteristic decelerating flow pattern, it results in lower peak pressures and longer inspiratory times. PCV is useful in situations where the lungs are stiff - it might reduce the incidence of barotraumas. It might also result in better gas exchange when used with high inspiratory times. The disadvantage of PCV is that tidal volumes are not guaranteed and depends on how stiff the lungs are.