What does "assist-control ventilation" mean?

Assist-control ventilation is a mode of mechanical ventilation that provides a combination of mandatory mechanical breaths and the patient's own spontaneous breaths. In this mode, the ventilator is programmed to deliver a set number of breaths at a predetermined tidal volume or pressure. If the patient initiates a breath, the ventilator responds by delivering an additional breath of the same set parameters, ensuring that the patient receives adequate ventilation regardless of their effort.

This assists patients who may be unable to maintain satisfactory ventilation on their own, while still allowing them the autonomy to initiate breaths as needed. The provision of a set breath for every patient-initiated breath ensures that there is a consistent and supportive ventilation strategy, which can be particularly beneficial in scenarios where patients may be weak or have compromised respiratory function.

Other modes of ventilation, such as spontaneous or pressure support ventilation, do not provide the same level of guaranteed mechanical breaths in response to patient effort, making assist-control a distinctly supportive mode tailored to meet varying patient needs while maintaining control over ventilation parameters.