The AIDS epidemic has heightened efforts to conserve blood, experts say.
Limiting blood transfusions, stockpiling blood for elective surgery or reusing a patient's own blood can reduce the risk of exposure to HIV, hepatitis or other bloodborne diseases.
Such techniques also lessen some of the demand on the often insufficient supply of donated blood in this country.
Because of the relative scarcity of blood and concerns about potential disease transmission, many blood providers have been encouraging hospitals not to use blood they don't need, said Bill Coenen, president of the Council of Community Blood Centers, which represents 59 independent blood centers that supply 40% of the blood collected in the U.S.
Blood conservation "took off after the fright about AIDS and blood," said Shelley M. Brown, M.D., director of blood bank and transfusion services at Lenox Hill Hospital in New York. "It has become more and more popular; just like any movement, it just takes time for the public to be educated about the options," she said.
Now, many more people give blood before surgery, and most hospitals have protocols for determining when a transfusion is appropriate, Dr. Brown said.
Safety first.Although the Food and Drug Administration requires all blood used in the United States to be tested for the presence of HIV, no one can guarantee with 100% certainty that a unit of blood is disease-free. It's estimated that one of every 225,000 units of blood might be tainted but undetected.
To put that in perspective, some 14 million units of blood are donated each year, and more than 20 million units of blood components, such as red cells and platelets, are transfused every year, according to the American Association of Blood Banks.
Blood may be tainted even though it's tested because the test used to screen blood samples measures the buildup of HIV antibodies. If a blood donor's infection is recent, HIV may not be detected because of an estimated three-week to six-month lag from the time a person becomes infected until there are enough antibodies present to test positive.
Collecting alternatives.Recognizing the public's concern about safety, groups such as the American Red Cross recommend that people store their blood for elective surgery. Such "autologous" donations help
prevent a drain on donated supplies of blood.
For December and January, the nation's blood supply is at 80% of the optimal level, said Felix Perez, a Red Cross spokesman. There are many reasons behind insufficient blood supplies. For example, East Coast layoffs have diminished the number of people willing to give blood during work-site donation drives, he said.
Health professionals also are increasing efforts to reduce the amount of blood needed for transfusion. For example, the nation's anesthesiologists, who perform more than half of all transfusions each year, are reducing the amount of red cells needed and using techniques to minimize bleeding during surgery, the New York State Society of Anesthesiologists reports.
In addition, more hospitals are using blood-salvaging devices that reduce the need for transfusion, experts said.
Haemonetics, a Braintree, Mass.-based manufacturer of a device that collects and washes a patient's own blood for reinfusion, has seen a shift in physicians' attitudes about transfusions.
"With the concern over safety in transfusion, it's had a very positive effect on the business," said Stephen P. Oliver, manager of investor relations. The average price for the company's Cell Saver is $25,000; the tubing and bags used with it cost $100 to $150 per patient.
conservation techniques can be applied post-operatively as well, Dr. Brown said. People who bleed after surgery, including hip replacement and heart patients, are having their blood collected and returned to them, she said.
Having friends or relatives donate blood on behalf of the patient also is thought to improve the safety of transfusions.
But Ronald Miller, M.D., professor and chairman of the department of anesthesiology at the University of California-San Francisco, warned colleagues at a recent meeting that so-called "directed donations" aren't necessarily safer and could be more dangerous. Family and friends often are first-time donors whose blood hasn't been previously screened for disease, while the nation's donor pool contains many repeat donors; their blood has been tested many times, he explained.
Synthetic blood replacements also offer the promise of relieving worries about disease-tainted blood. A handful of companies are developing blood or blood product substitutes, but those products won't be on the market for several years.