What is the flow shape in assist control ventilation?

In assist control ventilation, the flow shape is characterized as square flow. This is because, during assist control mode, the ventilator delivers a preset volume of air or a set pressure at a rapid rate, producing a constant flow for the duration of the breath. This results in a sharp, vertical rise in flow that is sustained for the entirety of the breath, forming a "square" appearance on a flow-time graph.

This characteristic is significant as it allows for a predictable and uniform delivery of air to the patient, helping to ensure adequate ventilation and oxygenation. The square flow pattern is particularly beneficial because it minimizes the work the patient has to do to initiate a breath, supporting those who may have compromised respiratory function.