Donor Screening and Deferral

The Donation Process

Education

When prospective donors enter a blood bank, they are asked to read educational materials. These materials contain information on the risks of infectious diseases transmitted by blood transfusion, including the signs and symptoms of AIDS. Prospective donors are asked to acknowledge in writing that they have read and understood these materials, have been given the opportunity to ask questions, and have provided accurate information. The prospective donors can elect to leave at this point without donating. (Self-deferral can occur at any point in the donation process when a donor voluntarily chooses not to complete the process.)

Health History

Prospective donors who do not self-defer proceed to the next step: giving a detailed health history. The history is designed to ask questions that protect the health of both the donor and the recipient. To ensure that every donor is asked the same questions, the AABB recommends use of a uniform donor history questionnaire. However, donor centers often create their own questionnaires, using the same general guidelines. In addition to questions about transfusion-transmissible diseases, prospective donors are asked questions to determine whether donating blood might endanger their health. If a prospective donor responds positively to any of these questions, he or she will be “deferred” or asked not to donate blood. The health history also is used to identify prospective donors who have been exposed to or who may have diseases, such as human immunodeficiency virus (HIV), hepatitis or malaria. These individuals are further evaluated and those at high risk of disease are deferred.

Physical Examination

The donation process includes an abbreviated physical examination that includes checking the blood pressure, pulse, and temperature. A few drops of blood are taken from a finger and tested to ensure that anemia is not present. An abnormality found in any part of the physical examination may be a cause for deferral. Donors also must meet the weight requirement of 110 pounds.

The Actual Donation

A prospective donor who passes successfully through these steps proceeds to the actual whole blood donation process, which takes about 20 minutes. The donor lies down or sits in a reclining chair. The skin covering the inner part of the elbow joint is cleansed. A new, sterile needle connected to plastic tubing and a blood bag is inserted into an arm vein. The donor is asked to squeeze repeatedly his or her hand to help blood flow from the vein into the blood bag. Typically, one unit of blood, roughly equivalent to a pint, is collected. After the blood is collected, it is sent to the laboratory for testing and component preparation. The donor is escorted to an observation area for light refreshments and a brief rest period.

Adult males have about 12 pints of blood in their circulation and adult females have about nine pints. The donor's body replenishes the fluid lost from donation in about 24 hours. The red blood cells that are lost are generally replaced in a few weeks. Whole blood can be donated once every eight weeks.

The Deferral Process

Individuals disqualified from donating blood are known as “deferred” donors. A prospective donor may be deferred at any point during the collection and testing process. Whether or not a person is deferred temporarily or permanently will depend on the specific reason for disqualification (e.g., a person may be deferred temporarily because of anemia, a condition that is usually reversible). If a person is to be deferred, his or her name is entered into a list of deferred donors maintained by the blood center, often known as the “deferral registry.” If a deferred donor attempts to give blood before the end of the deferral period, the donor will not be accepted for donation. Once the reason for the deferral no longer exists and the temporary deferral period has lapsed, the donor may return to the blood bank and be re-entered into the system.

08/05

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