How Much Fluid Do You Need Perioperatively?

People can lose up to 25% of their blood volume and not have any change in vital signs. You're an output people look at, but again, you're an output is not a great marker. A very low CVP is probably helpful in the sense that if your CVP is one or two, you probably are not hypervolemic. And CVP trends if everything else stays normal, stays the same, may be useful. But in general, CVP not a great way either.