Jeffrey McCullough - Transfusion Medicine

A major factor influencing whether blood donors will make subsequent donations is their experience at each donation. Thus, it is important that the blood collection staff provide a warm, friendly, professional, and efficient environment in which the medical assessment and blood donation can take place.

When the donor initially presents at the donation site, identifying information is obtained for the permanent record. This includes name, address, telephone number, birth date, social security number (if allowed in that state), and previous donation history, including any names under which previous donations might have been made. To prevent iron depletion, individuals may donate a red cell unit no more often than every 56 days, or 112 days if they are giving a double unit by automated collection. At the time of registration, the prospective donor is given information about blood donation, transmissible disease testing, and factors or behaviors that would preclude blood donation. Information may also describe the agencies that are notified in the event of a positive test result for a transmissible disease. In obtaining the medical history, a staff member asks or reviews donor responses to questions about these factors. Either at the time of registration or before the blood unit is made available for distribution, the identity of each donor must be checked against a registry of individuals known to be unacceptable as blood donors [6]. Although this process is required by the FDA and is widely used throughout the United States, there has never been a thorough study to establish its value, and some registries do not share information that could limit effectiveness.

Table 4.1 Strategies for collecting safe blood.

There is no standard maximum age for blood donation. Most blood centers do not have a specific upper age limit and instead evaluate each donor individually. Elderly donors have more medical conditions and medications than younger donors, but they do not experience more adverse reactions to donation [7, 8]. Elderly donors have slightly decreased iron stores, especially if they have been regular donors [9–11], but they can safely contribute to the nation’s blood supply [12]. Although 18 years is typically the age at which individuals can take responsibility for their own actions, the lower age limit for blood donation is usually 17 years, and most states have passed laws that also allow donation of whole blood at the age of 16 with parental consent. These special laws dealing with blood donation enable high school students to donate. However, donor safety concerns regarding possible health effects of iron depletion in this age group have led some blood centers to self‐regulatory steps, such as longer minimal donation intervals (e.g., no more than two times per year) and prohibiting automated collection of double red cell units in females younger than 19 years [13].

The medical history is an extremely important part of the selection of donors because it can reveal reasons why donation might not be wise for the donor or reasons why the donor’s blood might pose increased risk for the patient. Because most blood organizations now use the computerized self‐administered history, the interview usually takes less than 10 minutes. Many blood organizations provide the opportunity for the donor to do this online in advance. In addition to obtaining responses to these specific questions ( Table 4.2), the interviewer attempts to assess whether the donor is in good general health, is not under the influence of drugs, and is able to give informed consent for the donation. The interview must occur in a setting that provides privacy for the donor. Although complete visual privacy is not always possible, visual distractions should be minimized, and the donor’s answers must not be audible to others. The interviewer reviews the response in the computer‐assisted donor history and then asks specific questions. The varied levels of computer‐assisted donor screening seem to be acceptable to donors and may decrease errors [14].

An interagency task force developed a standard donor history questionnaire (DHQ) that is approved by the FDA ( https://www.fda.gov/vaccines‐blood‐biologics/guidance‐compliance‐regulatory‐information‐biologics/biologics‐guidances) and is used as a template by most blood banks. There is supplemental material for the DHQ regarding responses to each question, together with a flow chart defining need for and duration of deferral ( http://www.aabb.org/tm/questionnaires/Documents/dhq/v2‐1/DHQ‐v2‐1‐Implementation‐Toolkit.pdf). The DHQ can be self‐administered by the donor or combined with direct questioning and is easily put in a computer‐assisted format. The questions designed to protect the safety of the donor include those regarding medications and whether the donor has a history of heart or lung disease, present or recent pregnancy, recent donation of blood or plasma, or bleeding condition. Questions pertaining to recipient safety include inquiry to the donor’s general health; the presence of a bleeding disorder, Chagas’ disease (although the question is not helpful) [15], or babesiosis; the injection of drugs; blood transfusion; tattoo or ear or body piercing; organ or tissue transplant; travel to areas endemic for malaria, Ebola, or Zika; recent immunizations; contact with persons with hepatitis or other transmissible diseases; ingestion of medications, especially aspirin; or previous notice of a positive test for human immunodeficiency virus/acquired immune deficiency virus (HIV/AIDS).

Individuals who have spent more than 3 months in the United Kingdom from 1980 to 1996 are deferred because of possible exposure to the causative agent of variant Creutzfeldt–Jakob disease, as are those who have spent 5 or more years in selected European countries. Based on studies in the United States and Canada, which have modified restrictions, 1–2% donor loss has been estimated because some form of this question has been included on the questionnaire [16–18].

Table 4.2 Complete list of medical history questions for blood donors.

Source : Fung MK, Eder AF, Spitalnik S, Westhoff CM, eds. Technical Manual, 19th edn. Arlington, VA: American Association of Blood Banks, 2017.

Potential donors who have resided in or traveled to malaria‐endemic areas are deferred for 12 months. However, most transfusion‐transmitted malaria is associated with lengthy residence in malaria‐endemic areas rather than routine or short‐term travel, especially when short‐term travel is concentrated in tourist areas that may have little or no risk [19].