Science Questions

How quickly can a person exsanguinate from a cut artery?

If you happen to have your jugular artery or femoral artery cut how long would it take for you to bleed out? I was having a heated discussion with someone about it. He says 36 hours. I say he’s nuts, it would just be a few minutes. Who’s right? Marie

Kat -  I think you are.  If you have an injury to a major artery you could be dead with a matter of minute from loss of blood.  This obviously happens all the time in serious accidents.  Very nasty stuff.  Basically you just have this massive drop in blood pressure.  You can’t supply blood to your brain, you can’t supply blood to your heart.  You conk out pretty quickly.  If it’s in terms of getting all the blood out of you it probably wouldn’t take that long either.  It’s probably good to get all the blood out of normal people anyway.

Chris -  You’ve got a cardiac output of five litres a minute.  In other words your aorta, your main blood vessel, has got 5 litres of blood running through it every minute.  Your circulating volume, the amount of blood in your body is 5 litres.  At most if you cut someone’s aorta, if they had an aneurism that burst they could potentially lose all the blood in their body in one minute.

Kat -  Yep, you’d be in trouble.  Also bleeding over 36 hours is extremely unlikely unless you had some condition like haemophilia which meant you couldn’t clot.

September 2008