Arming Yourself With the Facts About Donating Blood

Since the earthquake, Southern Californians have been rolling up their sleeves to donate blood, says Barbara Wilks, an American Red Cross spokeswoman. Some were responding to donation requests made when the blood supply here dropped dangerously low in early January; other donors thought the quake might greatly increase the need for blood.

“The supply is now in good shape, except for Group O, which is in chronic short supply,” Wilks says.

Here, some commonly asked questions about blood donations.

Question: How long does it take to donate blood?

Answer: The collection process takes four to 10 minutes, says Cheryle Babbitt, director of donor services for the American Red Cross, Southern California region. Donors must first answer questions about their health and are asked to stay afterward for a few minutes to be sure they feel OK. “So allow an hour to an hour and 15 minutes,” Babbitt says.

Q: What type of blood is most in demand?

A: “Currently, the largest shortage is for Type O, both negative and positive,” Babbitt says.

Explained simply, those with positive blood types have a particular protein in the bloodstream, says Dr. James Mosley, USC professor of medicine and director of the Transfusion Safety Study, a government-sponsored investigation. Those with negative blood types lack this protein.

Type O negative is the universal donor type, because it can be given to anyone. “Type O negative is also preferred for infants,” Babbitt says, “because their blood types are not yet well developed.” Those with positive blood types can receive negative blood, but those with negative cannot receive positive.

About 85% of all people have positive blood types.

Q: Which types of blood are most common?

A: Here’s a rough breakdown of blood types among the U.S. population, provided by the American Assn. of Blood Banks:

O positive: 37%

O negative: 7%

A positive: 36%

A negative: 6%

B positive: 9%

B negative: 1%

AB positive: 3%

AB negative: 1%

Q: What information is needed when you donate?

A: You’re asked your weight (on your honor). Your body temperature, blood pressure and pulse are taken. A drop of blood will be taken to test for anemia. You don’t need to know your blood type.

Q: Should I follow any special diet before giving blood?

A: No. Eating normally is best.

Q: How much does it hurt?

A: To simulate what it will feel like, Babbitt says, “pinch the inside of your elbow for one minute.”

Q: How much blood is taken?

A: About a pint.

Q: Any special advice for the squeamish?

A: Alert the person who will take your blood if you have a history of fainting or dizziness so you can be watched closely. Take along a stereo headset with soothing music. Tune out other people’s negative talk. And remember, it’s voluntary. You can always change your mind.

Q: How often can I donate blood?

A: Healthy people can donate blood every 56 days. That interval allows time for the blood supply to replenish itself.

Q: Who shouldn’t donate?

A: Pregnant women, people who weigh less than 110 pounds, people who have a cold or the flu.

Q: Who can’t donate?

A: People who are HIV-positive or at risk of being HIV-positive; anyone who has had hepatitis B; certain other medical conditions, including a history of cancer, could disqualify a donor; the Red Cross requires donors to be at least 17.

Q: What is the risk, for donors, of coming into contact with HIV-contaminated needles?

A: In the United States, there is no risk. A new sterile needle is used for each donor.

Q: What happens to the blood after it’s collected?

A: It goes to a laboratory, where it is tested to determine type and whether it is negative or positive. It is tested for syphilis, hepatitis B and C, and for HIV. The Red Cross warns potential donors not to use donations as an opportunity for free HIV testing. If infected recently, donors may have a negative test result yet be capable of infecting others. If an infected donor is still in the window period--which can be six months or even longer--the virus is present but antibodies to it have not yet formed. The screening tests detect antibodies, not the virus, Babbitt says.

To further minimize the chance of contaminated blood slipping through, careful attention is paid to the answers each donor gives to health questions about risk behaviors for acquiring AIDS, she says.

Donors whose sample tests positive for any of the above diseases are notified, says Marcia Lane, a spokeswoman for the American Assn. of Blood Banks.

Blood that passes the tests is sent to a processing lab, where components such as red blood cells, plasma and platelets are separated out. After labeling, the blood is ready for distribution to hospitals.

Q: After donating, are there any special diet precautions?

A: No, although most centers offer refreshments such as juice and crackers. The Red Cross asks donors to relax for a few minutes. Although most people feel fine after donating, some may have a faint feeling, upset stomach or other minor problem.

Q: What is the status of artificial blood? Will it make blood donations unnecessary anytime soon?

A: Several blood substitute products are under development, with many companies now involved in phase one trials, according to Biomedical Business International, a Santa Ana-based industry publication. But the race has been besieged with problems, such as some volunteers reporting high blood pressure and other unexpected side effects.

Even so, some industry experts predict that artificial blood could be on the market in two years--a timeline others term highly optimistic.

But artificial blood will never replace the need for human blood, says Dr. Robert Winslow, UC San Diego professor of medicine and a national expert on artificial blood. “Many blood substitutes are manufactured from human blood.” Artificial blood will be used mainly for elective surgery, Winslow says, then trauma.

Q: Where can I donate? Do I need an appointment?

A: The Red Cross conducts blood drives at many companies. There are also mobile collection units at shopping centers and other public sites. Or call (800) 974-2113 to find a site. Making an appointment will save you time.