The blood centre as a community health resource.

Blood centres in the USA encounter over 35,000 blood donors every day, a number that is far exceeded worldwide. This daily encounter of thousands of people with the healthcare system offers an unusual opportunity for blood centres to engage these donors in ways that contribute to individual and community health. In addition, a positive interaction at the blood centre may encourage donors to return more often, thus enhancing the blood supply. The wealth of medical information gathered by blood centres also presents an opportunity for epidemiological studies of health and illness that affect the community at large. Donors receive a 'mini-physical' as part of the donor qualification process. Required procedures include blood pressure measurement and haemoglobin determination. Targeted education, counselling and referral of donors with hypertension and/or low haemoglobin engages them in the care of critical personal health issues. Carbonyl iron supplied to female donors of child-bearing age replaces iron lost in the donation and can retain them as active blood donors. A range of optional screening tests and procedures offer enhanced interactions between the donor and the blood centre. Inexpensive tests, such as cholesterol and random blood glucose determination, can detect abnormalities that may initiate further medical interventions to address cardiovascular and diabetic risks. These enhanced medical interactions with donors must be undertaken with care and appropriate medical supervision. However, the opportunity, indeed the responsibility, to act on important medical information enhances the range of medical support for donors and is an opening for blood centres to expand their involvement in the health of the community.

Overcoming blood shortages: red blood cell and platelet substitutes and membrane modifications.

Blood shortages are increasingly common as the donor base declines and extensive restrictions on blood donation disqualify many donors. Red blood cell (RBC) and platelet substitutes have long been anticipated as alternatives to standard transfusions. However, difficulties in manufacturing, efficacy, and safety have slowed the development of these products. New understanding of the relationship between blood viscosity, oxygen transport, and vasoactivity have led to more effective RBC substitutes, several of which are in advanced clinical trials. In addition, creative approaches to RBC membrane modification, such as the enzymatic cleavage of ABH glycoproteins, may lead to a universal RBC. Advances in the understanding of platelet membrane behavior at low temperatures may lead to extended platelet storage at refrigerator temperatures. Standard transfusions of human RBCs and platelets will not be replaced soon. However, these new products will be a useful alternative for selected clinical applications and will lessen our dependence on our marginally adequate blood supply.