The doctor doesn't need to drain all your blood to figure out if there is something going on.
"Can you think of no way someone could drain the blood?"
"We have to begin trying to drain blood from a stone."
The man's brown face turned gray as blood drained from it.
Now more requests do you want to drain all the blood from my body?
"Carol is going to drain our blood to make the next one."
I saw a man drain her blood into a bathtub.
He drained so much blood from me now that I was scarcely about to stand.
He held still while she made a precise cross cut and drained the blood.
The doctor can use a chest tube to drain the blood.