Recycling Blood

Being your own donor

Though donations by Americans have picked up in the past few years, the supply of blood barely keeps up with the demand. Use of donor blood rose 76% between 1971 and 1979 and may go higher if surgery increases as the population ages.

Concerned by the blood crunch, doctors are turning to once out-of-favor methods of conserving blood during surgery.* Two techniques now making a comeback:

Intraoperative Autotransfusion. A patient's blood, shed in the course of an operation, is not discarded but instead recycled into his body. Autotransfusion has been tried occasionally since the 1800s, but the equipment used in the process damaged the blood. Furthermore, contaminated blood caused infection. Worse still, air was sometimes pumped into the patient, killing him.

New methods have virtually eliminated these risks. Blood is cleansed to remove damaged red cells and other debris. The collected blood can be hung in a plastic bag above the patient's head and transfused by gravity. Autotransfusion is especially suitable where blood loss is great, as in trauma patients or those undergoing cardiac or orthopedic surgery. At Boston's Beth Israel Hospital, where autotransfusion is used in all heart operations, the need for donor blood in such surgery dropped 60% last year. Using the patient's own blood eliminates the possibility that his blood type will be mismatched and reduces his chances of contracting blood-borne diseases. Says Jerome Hauer, a blood specialist at Beth Israel: "The patient gets the best blood--his own."

Hypotensive Anesthesia. By depressing a patient's blood pressure to very low levels, anesthesiologists can lessen the amount of blood lost and give the surgeon an almost clear field in which to work. This is particularly useful in surgery on vessels that carry blood to the brain and in orthopedic operations like hip implants. The anesthesiologist anesthetizes the patient, then infuses a drug, usually nitroprusside, to dilate the blood vessels. This causes the pressure of blood against the vessel walls to drop from a normal reading of, say, 120/80 to as low as 65/50. The anesthesiologist must be careful that enough blood continues flowing to the brain, heart and kidneys.

Though these techniques are once again popular, their full impact on blood conservation is yet to be assessed. But they are already of lifesaving importance to Jehovah's Witnesses, whose faith forbids transfusions of donor blood.

Temporary blood substitutes are also being tested in the U.S.

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