Vampire attack and biology

As vampires aren't human, it's a moot point as to how much blood their stomach could hold. I always assumed it didn't go to their stomachs, which would be a bit silly, but was infused quickly throughout their whole body.

As for blood loss...

Class I Hemorrhage involves up to 15% of blood volume. There is typically no change in vital signs and fluid resuscitation is not usually necessary.


Class II Hemorrhage involves 15-30% of total blood volume. A patient is often tachycardic (rapid heart beat) with a narrowing of the difference between the systolic and diastolic blood pressures. The body attempts to compensate with peripheral vasoconstriction. Skin may start to look pale and be cool to the touch. The patient may exhibit slight changes in behavior. Volume resuscitation with crystalloids (Saline solution or Lactated Ringer's solution) is all that is typically required. Blood transfusion is not typically required.


Class III Hemorrhage involves loss of 30-40% of circulating blood volume. The patient's blood pressure drops, the heart rate increases, peripheral hypoperfusion (shock), such as capillary refill worsens, and the mental status worsens. Fluid resuscitation with crystalloid and blood transfusion are usually necessary.


Class IV Hemorrhage involves loss of >40% of circulating blood volume. The limit of the body's compensation is reached and aggressive resuscitation is required to prevent death.

efreysson said:

Thanks for responding.



Can you tell me more about the mental effects?

And the setting I have in mind is pre-industrial. How long would recovery from the first two stages take without modern medicine?

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Google is your friend.

Vampire kill / turning bites are most often portrayed as a direct strike to the carotid artery. This is high pressure / high speed blood coming directly from the heart, so in terms of treatment, you're looking at a spurting wound on the neck.

Also, most often, vampires aren't depicted as "filling up on" blood. They're replacing the blood their bodies no longer produce, so they can take in as much as a human can lose, assuming they've not already bitten someone else. It's a handy-wavy kind of pseudo-biology accepted by readers / fans of the genre. A vampire takes in blood; that blood then circulates through the vampire's system.

Considering that vampires are fantasy creatures, non-existent in the world we humans inhabit (unless you really believe otherwise), you are totally free to make them function in whatever manner works for your story. No point in asking about medical research on their biology.

caw

Sat Nam! (literally "Truth Name"--a Sikh greeting)

Can't tell you anything about vampire biology. But I can tell you what it feels like to lose 25% of your blood. (I experienced a tonsillectomy from hell.) After I was stabilized, I was dizzy much of the time. My mother told me I looked very pale. I was excused from physical exercise for at least a month. I fatigued easily. I was a hair's breadth from a transfusion, but fortunately didn't need one. Someone who had to do hard labor after a vampire attack could die. Might not happen if they could take time off to rest.

Blessings,

Siri Kirpal

efreysson said:

Thanks for responding.



Can you tell me more about the mental effects?

And the setting I have in mind is pre-industrial. How long would recovery from the first two stages take without modern medicine?

Click to expand...

I'm sure the mental effects can be whatever you want since bleeding to the point of unconsciousness is described, but not while being gnawed on by a vampire. Without the vamp and just bleeding, first there is some confusion, then dizziness, then an inability to stand or walk combined with tunnel vision, then the floor looks very inviting and then you pass out. When there's not enough blood getting to your brain, fear turns to confusion.

As far as recovery goes, red cells are constantly being made and will ramp up production after blood loss. For severe blood loss that is still survivable, within a few days to a week or so they'd be up to walking but tired and short of breath. Essentially full recovery basically 6-8 weeks, though still tired. Full recovery 2-3 months.

Competitive eaters often train by drinking a gallon or two of water to train their stomach to distend easily

Well, the human stomach can hold about a liter of liquid typically, but it can expand, which puts the maximum at about a gallon. But of course, you'd be full long before then. The human body contains anywhere from 4.7 to 5.5 liters of blood, so I'd say a victim would be close to incapacitated and would definitely need some kind of treatment. The victim would be feeling cold, clammy, and weak from losing that much blood, and probably wouldn't be able to stand very easily. The main thing I'd worry about is stopping the bleeding so the victim doesn't lose any more blood than necessary. Bottom line though, they'd almost certainly survive if they got help quickly enough. But everybody is different, the effects often depend on how much you've eaten and how hydrated you are.

efreysson said:

Can you tell me more about the mental effects?

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Dizziness, loss of equilibrium, blacking out or a hazy effect, time slowing, unable to understand questions asked of you, shutting down of sensory perception, especially touch, blurring or narrowing vision, hallucinations and passing out. But that's just me.

Comes back pretty quick with fluids, leaves a bit of a headache and some grogginess as well as a temporary dislocation, not realizing where you are or, sometimes, who people are.

Jeff

blacbird said:

Considering that vampires are fantasy creatures, non-existent in the world we humans inhabit (unless you really believe otherwise), you are totally free to make them function in whatever manner works for your story. No point in asking about medical research on their biology.

caw

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I did ponder moving the thread BUT, I do think there are genuine scientific questions here that can be answered without speculation. So here it stays.

And thank you folks for answering with facts.

Cyia said:

Vampire kill / turning bites are most often portrayed as a direct strike to the carotid artery. ...

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Not necessarily. You have very large jugular veins in the neck as well that can bleed a lot of blood fast but are not under the kind of pressure an artery is.

Red blood cells turnover every few months so the body, provided it had the right nutrition, would recover completely in a couple months.

Right after you have a large bleed you are going to have low blood pressure and might need to lay flat to keep from passing out. However, in a few hours, faster if you are very well hydrated, fluid will shift from your vascular space into the bloodstream. Your blood pressure would recover but now you don't have enough red cells to carry the O2. So you'd be weak, tired and you'd still have a too-fast heart rate as your body responded to low O2 in your vital organs.

I will also add that you can see a vasovagal response so add in nausea, and cool clammy skin.