RE: How would you measure the volume of all the blood in your body?

[ovij]

Both of the methods used take quite a while. I know the constant perfusion method can take up to 4 hours. In an emergency quicker diagnostic test are used to identify the problem, like using specific blood markers from a blood test. Although these values may not always be the most accurate, the speed with which they can be obtained is useful in deciding how to proceed in an emergency.