What is the benefit of "double red" blood donation over whole blood donation?

May 8, 2010 10:01 AM

What is the benefit of "double red" blood donation over whole blood donation?

I am a regular whole blood donor. About a year ago I tried the "double red" donation process, where they hook you up to a machine that filters out your red blood cells, and pumps the rest (plasma, platelets, etc.) back into your arm. Apparently, they can take twice as many red cells this way compared to the regular whole blood process. I didn't really care for it, as it took quite a bit longer than the whole blood process, and feeling the cold plasma being pumped back into my arm was kind of uncomfortable.

Ever since then, I've been wondering why they came up with this new method. If you do double reds, you have to wait twice as long (16 weeks instead of 8) before you can donate again. So what's the point? If I were to switch from doing whole blood donation every 8 weeks to doing double red donation every 16 weeks, aren't they still getting the same amount of useful blood from me either way, over the course of a year? Whole blood donation is a lot quicker and easier, and the double red machines can't be cheap to purchase and maintain. I'm just trying to figure out why the Red Cross seems to be pushing the double red option so heavily. I get asked to do it every time I go in now, and when I decline, they act somewhat disappointed.

posted by Nothlit to Health & Fitness (6 answers total)

From the Red Cross:


Red cells are the most transfused blood component, and certain blood types are often in short supply.

Double red cell donations from Type O donors and donors with Rh-negative blood types play a very important role in maintaining blood supply levels.

Donors need to meet slightly higher hemoglobin and body height/weight requirements in order to be able to give a double red cell donation.

So my guess is that in your area red blood cells are in higher demand than other blood components (this is true in most but not all places; certainly it is where I work). Also you meet the height/weight and hemoglobin requirements so you are one of a smaller pool of donors who can do that type of donation.

Good for you for donating in the first place; I hope they don't pester you so much that you stop donating.
posted by TedW at 10:08 AM on May 8, 2010

Best answer: Most donors aren't as regular about donating as you. They might only do it 1-3 times a year. This way, the Red Cross can get 'more bang for the buck' per visit.
posted by barnone at 10:10 AM on May 8, 2010

Best answer: I suspect that it's predicated on the notion that most donors don't max out the frequency of blood donation. In other words, on average donors are more likely to donate less frequently than every 16 weeks anyway. For those who donate more frequently the amount of red blood cells procured over repeated visits may be unchanged, but for those who don't, there will potentially be a net gain in products (assuming that those donors don't further reduce their rate of donation, which seems reasonable enough).

The Red Cross claims that despite adding 30 minutes to the process, many donors prefer double red donation because they are left with more blood volume at the end of the process, so they feel less hypovolemic (i.e. "dehydrated" in common parlance, though that term is misused), and the needles are apparently smaller and more comfortable.

I can't speculate on the expense of performing double red donations...
posted by drpynchon at 10:12 AM on May 8, 2010 [1 favorite]

In my country, the blood service uses component donation to collect platelets - and as red blood cells are not lost, platelet donors can donate more often.

Whole blood donors have to wait 16 weeks between donations, while component donors (depending on which components are taken) can donate as often as every 2 weeks.
posted by Mike1024 at 10:43 AM on May 8, 2010

Response by poster: Ah, I guess that's the point I hadn't considered: that most people probably don't donate as regularly. So for someone who only goes in once or twice a year, doing double reds would result in a net increase in blood supply. I guess the benefit outweighs the cost of the more complex equipment necessary to perform the collection.
posted by Nothlit at 10:57 AM on May 8, 2010

The other possible benefit is the blood type thing. My memory of bio is fuzzy, but Wikipedia confirms that blood type is based on proteins or something on the surface of red blood cells. If your blood type is one that is in high demand, it may be that they really need the red cells, and the plasma (which is not typed) they can get from donors who have a more common blood type.

On preview, I think TedW's quote sort of points at that, but it's not made explicit.
posted by spaceman_spiff at 3:52 PM on May 8, 2010