If you need an emergency transfusion, the quality of the blood you receive should be the least of your concerns. And donated blood poses very little risk of disease. (See How Safe Is the Blood Supply?) If, however, you have the luxury of planning for elective surgery, you can take steps to reduce your risk even further.

• Autologous blood donation — This fairly common procedure involves having your own blood drawn days or weeks before surgery, then getting it transfused back during surgery. With adequate planning, healthy adults typically can give three or four units of autologous (self-donated) blood, which is more than enough for most procedures that require transfusions. (Note: Directed donations, in which family members or friends donate blood for a specific person, are not recommended. Such donations can be riskier than blood from the public supply because directed donors may feel pressure to conceal risk factors for blood-borne disease. Blood donated by a relative also increases the risk of a rare but potentially life-threatening condition in which white blood cells attack the body.)



• Hemodilution — This procedure, which is not widely practiced, involves drawing several units of blood from the patient in the operating room immediately before surgery. The removed blood is replaced with a liquid solution, which dilutes the remaining blood in the body. During surgery, the patient "bleeds" diluted blood, reducing the actual blood loss. The withdrawn blood is then replaced at the end of surgery.



• Blood salvage — In the operating room, machines remove blood from the surgical site, cleanse the blood, remove contaminants and prepare it for re-infusion into the patient. The technique is used mainly during operations that involve greater amounts of blood loss and little risk of contamination, such as heart or vascular surgery.

How Safe Is the Blood Supply?