The pressure support level is automatically adjusted by the ventilator to maintain appropriate breathing frequency, tidal volume, and end-tidal carbon dioxide, depending on the patient's pathologic condition

This mode description pertains to which of the following ventilator control types?
a. Adaptive c. Knowledge-based
b. Set-point d. Neurally adjusted ventilatory assist

ANS: C
The knowledge-based control type has the set-points automatically adjusted according to a rule-based expert system, such as breathing frequency, tidal volume, and end-tidal carbon diox-ide levels. An example of this kind of control type is SmartCare on the Dräger EvitaXL. The adaptive control type changes set-point types based on the patient's changing condition. For example, mandatory breaths are pressure limited, and this pressure-limit setting is automatically adjusted between breaths to achieve the preset tidal volume. In the set-point control type, the output of the ventilator automatically matches a constant operator-preset input value. Neurally adjusted ventilatory assist is not a control type. It is a mode that adjusts set-points automatically, based on the electrical activity of the diaphragm and the level of response to the electrical activi-ty as set by the operator.