untreated blood loss

How severe can blood loss be and have the person survive if just left with no treatment?

I have a couple of vampire slayer kids rescue a victim of a vampire attack, and not wanting any attention drawn to their slaying, they just hide her away somewhere and see if she survives. How severe could her blood loss be and she still be alive when they check on her the next day?

Do you mean she has lost blood but is no longer bleeding?

In that case, if we are talking about an adult who wasn't already anemic, than a loss of up to 2 pints of blood is compleatly plausable. You could maybe go a little more but she would be really weak.

Make sure they give her something to drink. She needs to replace som fluids.

edited 14th Jan '13 2:14:59 PM by HistoryMaker

Actually, I'd say the figure is closer to 1.5 to 2 litres (or approx 3 to 4 pints) based on what I've come across. The theory is that the body (of a healthy person) should be capable of compensating up to a loss of 30% of blood volume; with an average person having 5 to 6 litres of blood. Before this point, a person would typically experience symptoms like a fast heart rate or a narrowed blood pressure but is otherwise, for the most part, alright. Moreover, the tipping point is a loss of around 40% (2 to 2.4 litres of blood), which is when the body's compensatory limits are reached and urgent treatment must be given to prevent death.

As such, what you have here is a range of between 1.5 to 2.5 litres to play with where a person is sick/weak, possibly unstable but not in immediate danger of death.

edited 14th Jan '13 2:45:39 PM by peasant

I admit I was being pretty conservative.

However for some reason I was picturing the victim as a small woman, (don't know what that says about me) so she'd be starting with under 4 L of blood.

Also someone who has rapidly lost 40% of their blood volume might be alive but probably wouldn't be conscious.

edited 14th Jan '13 3:17:58 PM by HistoryMaker

From Wiki

"Typically, a healthy person can endure a loss of 10–15% of the total blood volume without serious medical difficulties, and blood donation typically takes 8–10% of the donor's blood volume."

In the UK blood donation is a pint ('Nearly an armful')

edited 14th Jan '13 3:31:03 PM by LastHussar

Depending on the wound placement anywhere from a pint to two liters. Extremities and/or non-important circulatory structures (minor veins, capillary beds, etc.) are your best bet. Torso, chest, neck/head and thigh wounds have your least chance of survival untreated. (And not just because of blood loss.)

It'd also be a good idea to keep pressure on the wound, stop as much blood as escaping as possible. /captain obvious

"Treatment" for blood loss can be fairly mundane.

Unless we're talking about the point where a blood transfussion is needed, just fluid replacement, rest and time will do it.

edited 21st Jan '13 4:54:42 AM by Natasel