Author Question: The description a mode where each breath is pressure limited and the pressure-limit level is ... (Read 59 times)

SO00 · **on:** Jul 16, 2018

The description a mode where each breath is pressure limited and the pressure-limit level is ad-justed automatically between breaths by using ventilatory mechanics to minimize the patient's work of breathing pertains to which ventilator control type?

a. Servo c. Adaptive
b. Optimal d. Auto-set-point

Question 2

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

jaygar71 · **Reply #1 on:** Jul 16, 2018

Answer to Question 1

ANS: B
The optimal control type has one ventilator set-pointin this case, pressure limitthat automat-ically adjusts to optimize another set-point, which in this case is the patient's ventilatory mechan-ics, according to some model of system behavior, and the output can be maximized or minimized dynamically. With the servo-controlled type, the ventilator output automatically follows a vary-ing input from the patient. The adaptive control type automatically adjusts one set-point to achieve another set-point as the patient's condition changes, such as pressure-limit changing to achieve a preset tidal volume. The auto-set-point control type enables the selection of which op-erator-adjusted set-point to enforce at the moment.

Answer to Question 2

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 Drger 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.