Educational use only — not medical advice. This is a teaching example and must not be used to guide care of any individual patient. Learn more →

Important Alarm in APV – High Pressure Limit

Why the high-pressure-limit alarm caps the pressure an adaptive mode can deliver, and how it can leave delivered tidal volumes below target.

APVAlarmsM2M5
Fig 1.As our last case illustrated, in APV, the ventilator titrates the amount of pressure it gives above PEEP with each breath to deliver the set target volume within the itime we choose. Ventilators have safety mechanisms that put an upper limit on the range of pressures that can be applied. On the Hamilton G5, the ventilator will not allow for the applied pressure plus set PEEP to be higher than the pressure limit alarm minus 10 cmH2O. If that ceiling is reached and the delivered tidal volume is still lower than the target tidal volume (as you can see as a exhaled tidal volume or VTE of 162ml on the left side of the screen), the alarm you see on the left upper corner will appear. Delivered tidal volumes wont increase unless you go in the alarms tab and change the upper limit of the airway pressure alarm.
Preview — work in progress