Well yes all patients usually have diminished intravascular volume post dialysis if they are set to remove fluid during treatment. As dialysis nurse stated, some patients BP drops when they stand and the staff need to know that when you leave and walk out your pressure is ok so you don't get dizzy and fall. It is a safety measure.
It is iportant to watch "trendng" in blood pressure. This is why we do pre and post B/P checks. I am less concerned with the actual numbers in B/P than I am with the amount of change in B/P after treatment. In other words, you may have an "ideal" B/P of 120/80, but it ay be hypotensive for you and cause problems. I hope this helps.