What is the measure of npo

It would be much much easier to answer this question

if we knew what "npo" means.

Last time I was in the hospital, "npo" meant "non per oro".

That's Latin for "nothing by mouth". It's the way the doctor

tells the nurses "Don't give him anything to eat or drink".

So in that case, the measure of "npo" is zero.

If you mean something else by "npo", you'll have to come back

and tell us what it means.