# Blood Donations / Save-a-Life Ratio

**URL:** <https://boards.straightdope.com/t/blood-donations-save-a-life-ratio/58869>\
**Category:** Factual Questions\
**Created:** [March 21, 2001, 3:35pm UTC](https://boards.straightdope.com/t/blood-donations-save-a-life-ratio/58869 "2001-03-21T15:35:19Z")\
**Posts on this page:** 8\
**Page:** 1

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**Author:** ![bup](https://avatars.discourse-cdn.com/v4/letter/b/6bbea6/32.png) [@bup](https://boards.straightdope.com/u/bup)\
**Post date:** [March 21, 2001, 3:35pm UTC](https://boards.straightdope.com/t/blood-donations-save-a-life-ratio/58869/1 "2001-03-21T15:35:19Z")

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What are the odds that donating a pint of blood will save  
a life?

I know a lot of it is used for elective surgery, and I  
_think_ a lot of it is used for research, and I hope they  
generally have enough so that sometimes it just goes past  
the expiration date.

So, does anybody know?

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**Author:** ![Ethilrist](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ethilrist/32/4604_2.png) [@Ethilrist](https://boards.straightdope.com/u/Ethilrist)\
**Post date:** [March 21, 2001, 3:38pm UTC](https://boards.straightdope.com/t/blood-donations-save-a-life-ratio/58869/2 "2001-03-21T15:38:00Z")

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Doesn’t much matter to me. If they only save one life for every thousand units, it’s worth it.

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**Author:** ![gigi](https://avatars.discourse-cdn.com/v4/letter/g/a587f6/32.png) [@gigi](https://boards.straightdope.com/u/gigi)\
**Post date:** [March 21, 2001, 4:39pm UTC](https://boards.straightdope.com/t/blood-donations-save-a-life-ratio/58869/3 "2001-03-21T16:39:49Z")

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WAG here, but it seems that the chances that a life will be saved by one pint of blood alone are tiny. If someone is in a life-threatening blood loss situation, they will need more than one pint. Still, your pint contributes to the life saved. I donate plasma and platelets and these are used in surgery, with one pint able to be used for more than one newborn, for example.

According to [http://www.redcross.org/donate/give/](http://www.redcross.org/donate/give/), “Your single donation can help save up to three lives.” Again, this would depend on what you meant by saving a life.

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**Author:** ![gigi](https://avatars.discourse-cdn.com/v4/letter/g/a587f6/32.png) [@gigi](https://boards.straightdope.com/u/gigi)\
**Post date:** [March 21, 2001, 4:48pm UTC](https://boards.straightdope.com/t/blood-donations-save-a-life-ratio/58869/4 "2001-03-21T16:48:25Z")

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From [http://www.drkoop.com/conditions/Blood\_Donation/page\_68\_319.asp:](http://www.drkoop.com/conditions/Blood_Donation/page_68_319.asp:)

> [@](#):
>
> Less than 5 percent of healthy Americans eligible to donate blood actually donate each year…About 14 million units (including about one million autologous donations) of blood are donated in the United States each year by about eight million volunteer blood donors. These units are transfused to as many as four million patients per year…The need for blood is great – on any given day, about 40,000 units of red blood cells are needed. Accident victims, people undergoing surgery and patients receiving treatment for leukemia, cancer or other diseases, such as sickle cell disease and thalassemia, all utilize blood. More than 23 million units of blood components are transfused every year.

I’m not sure how much blood “expires”–it all seems needed.

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**Author:** ![bup](https://avatars.discourse-cdn.com/v4/letter/b/6bbea6/32.png) [@bup](https://boards.straightdope.com/u/bup)\
**Post date:** [March 21, 2001, 5:08pm UTC](https://boards.straightdope.com/t/blood-donations-save-a-life-ratio/58869/5 "2001-03-21T17:08:14Z")

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> [@](#):
>
> \*Originally posted by gigi \*  
> \*\*WAG here, but it seems that the chances that a life will be saved by one pint of blood alone are tiny. If someone is in a life-threatening blood loss situation, they will need more than one pint. Still, your pint contributes to the life saved. \*\*

Fair enough. I guess I’d like to know “X% of donated blood  
is used in situations in which the recipient would most  
likely have died otherwise,” and the Red Cross probably  
doesn’t go around giving that number too readily, because  
it might discourage people from donating.

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**Author:** ![mnemosyne](https://avatars.discourse-cdn.com/v4/letter/m/c4cdca/32.png) [@mnemosyne](https://boards.straightdope.com/u/mnemosyne)\
**Post date:** [March 21, 2001, 10:23pm UTC](https://boards.straightdope.com/t/blood-donations-save-a-life-ratio/58869/6 "2001-03-21T22:23:04Z")

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I’m sure some of it does expire, due to such things as the need to blood-type people. If there is high demand for 0- blood, wouldn’t there be a chance that A+ go bad? They can only store blood for a certain amount of time, too. It’s possible that none of it expires in certain places (bigger cities, perhaps), but in smaller hospitals it does go bad.

Just a WAG, though 🙂

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**Author:** ![fatherjohn](https://avatars.discourse-cdn.com/v4/letter/f/b2d939/32.png) [@fatherjohn](https://boards.straightdope.com/u/fatherjohn)\
**Post date:** [March 22, 2001, 2:13am UTC](https://boards.straightdope.com/t/blood-donations-save-a-life-ratio/58869/7 "2001-03-22T02:13:19Z")

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[QUOTE]  
\*Originally posted by bup \*  
\*\*

> [@](#):
>
> Fair enough. I guess I’d like to know “X% of donated blood  
> is used in situations in which the recipient would most  
> likely have died otherwise,” and the Red Cross probably  
> doesn’t go around giving that number too readily, because  
> it might discourage people from donating. \*\*

Another WAG here, but, it might very well be that current donation is sufficient that, in the last x years, not a single person has died for lack of available blood for transfusions.

This conjecture is supported by the fact that blood is available for research - presumably, saving lives would take priority.

Further, if somebody had died for lack of available blood, I have a feeling we would have heard about it. Certainly the Red Cross (or whoever) is not afraid to let everyone know that blood supplies are “dangerously low.”

Thus, the marginal change in probability per pint of blood might be very close to zero. (Heck, it might even be negative, if you think that blood transfusions sometimes increase peoples’ chances of dying).

And I agree that the Red Cross (or whoever) would be disinclined to publicize this sort of thing, for fear that it will discourage people from donating blood.

Of course, if enough people stopped donating, it might very well endanger lives.

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**Author:** ![dwyr](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dwyr/32/363_2.png) [@dwyr](https://boards.straightdope.com/u/dwyr)\
**Post date:** [March 23, 2001, 3:18am UTC](https://boards.straightdope.com/t/blood-donations-save-a-life-ratio/58869/8 "2001-03-23T03:18:02Z")

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I can only answer for my geographical area of course (Ky), but very few donated units expire. If a unit does reach the expiration date without being used it’s sent back to the blood center (a private one, not Red Cross). There they rejuvenate the unit and it is put in with the frozen stock. Frozen units are kept as an emergency reserve in case there are no donated units available anywhere and they have a ten year shelf-life compared to around 35 days or so for a liquid unit. Blood supplies here are often tight though and our local blood center often buys units from any state that has an excess. In the ten years I’ve worked at this hospital I’ve noticed that they’ve had to dip into the frozen stocks most often in the past two or three years. Usually it’s for type O blood because it’s used in all trauma cases, being compatible with all other types.
