We have a new physician who is insisting that we measure tidal volume on the inspiratory limb instead of the expiratory. Has anybody changed to this and what whould be the reasoning behind such a change?
so does he want to know what is being delivered? Which you already now with what is dialed in, right. And what about leaks around the ETT changing the Vt?
I'm not sure what he is looking for exactly. We were doing a ventilator check, while he was present. He started questioning us about the check and why we were using the expiratory limb instead of the inspiratory. I assume he wants to be sure that we are delivering the ordered VT. He stated this was done at a different facility he worked at.
The only time that I like to look at inpiratory limb vt would be when the tidal volume returned is distorted by a leak in the et tube or with uncuffed tubes or leaking chest tubes. You might gain insight as to what is being lost or what is being applied as a vt. Some people use an inspiratory vt as a modified disconnect alarm. Most ventilators have a calibrated inspiratory vt already built in so you may be reduntant.
I believe that most new generation ventilators display what volume is set, a measured inspiratory TV and a measured expiratory TV. The only time I would measure either volume is if I think the ventilator is not correctly measureing these volumes, or to confirm the values that a possible leak is present.
sometimes ventilators can be out of calibration and what TV is set, isn't exactly delivered, it may be more or less than what is dialed in as a setting. Usually biomed with calibrate this so that they are acurate. So I am not sure what was your purpose of check the TV? Remember who's to say the piece of equipment that you are using to varify the TV may be out of calibration, when was it last checked?