Too Slow to Rise: How Rise Time Affects Patient Comfort

Rise time is the interval required for the ventilator to achieve the target pressure in pressure control or pressure support modes. It is also referred to as the pressurization rate, and it directly influences the peak inspiratory flow delivered to the patient.

When the rise time is set too slow, the pressure increases gradually rather than promptly. This can be uncomfortable for patients who are breathing rapidly or have strong inspiratory drive, because the ventilator flow does not meet their demand, leading to increased work of breathing.

In this example, the pressure–time scalar demonstrates a slow, sloping rise toward the target pressure, producing a triangular-shaped inspiratory pressure waveform instead of the expected square waveform. This inadequate pressurization likely contributed to the high respiratory rate (47 breaths/min) observed in the patient.