In Assist Control Ventilation (AC), what happens if the inspiratory effort exceeds the set sensitivity?

In Assist Control Ventilation (AC), when a patient's inspiratory effort exceeds the set sensitivity, the feature designed to assist the patient's breathing is triggered. In this mode, the ventilator is set to deliver a fixed tidal volume for every breath it provides, regardless of whether the breath is initiated by the patient or the ventilator itself.

If the patient initiates a breath and their effort exceeds what is necessary for the ventilator to recognize the effort, the ventilator will still deliver the predetermined tidal volume as set by the caregiver. This ensures that the patient receives adequate ventilation support and maintains consistent respiratory function.

The other options do not align with the principles of assist control ventilation. If no breath were delivered, it would counteract the purpose of providing assistance when the patient is capable of initiating breath. The use of the patient's own tidal volume isn't typical in this mode since AC is designed to ensure that a set volume is provided to maintain respiratory support. Ignoring the effort is also not accurate, as the ventilator is actively responding to the patient's efforts and delivering set tidal volumes accordingly. Thus, the correct understanding of AC indicates that a fixed tidal volume is reliably delivered in response to the patient's respiratory efforts.