“And the blood in these veins,
Isn't pumping any less than it ever has.
And that's the hope I have,
The only thing I know is keeping me alive”

Paramore – Last Hope Lyrics on LyricsMode
She knows that her body is still alive, and shows no sign of dying out, and even though she feels like there is no hope inside, really she knows that her blood is still pumping, and there is no way out other than the blood to stop pumping.