[Malsua]

I’m not a Dr. but do bones carry blood? I thought that was the job of arteries and veins. If you've enough trauma to break a femur, the chances that your femoral artery was severed are quite elevated. You'll bleed out in minutes if it's completely severed.

[tioga]

Emergency medicine uses IO access if venous access is unattainable......I think they estimate you lose 1500 mL from a femur fracture. Enough to cause significant blood loss.

The marrow of long bones has a rich network of vessels that drain into a central venous canal, emissary veins, and, ultimately, the central circulation. The bone marrow therefore functions as a noncollapsible venous access route when peripheral veins may have collapsed because of vasoconstriction. This approach is particularly important in patients in shock or cardiac arrest, when blood is shunted to the core with peripheral vasoconstriction. The IO route allows medications and fluids to enter the central circulation within seconds.