Blood transfusions cause "tens of thousands" of non-infectious adverse reactions in hospitalized patients annually and many of them are quite serious resulting in longer, more costly care, says Matthew J. Kuehnert, MD, director of the Centers for Disease Control and Prevention's Office of Blood, Organ, and Other Tissue Safety.
But until now, there hasn't been an organized effort to define them, count them, and find better ways to prevent them.
"Many of them are preventable," Kuehnert says. "But we won't really know until we start tracking them."
The effort, called the Hemovigilance Module, is a joint project between the CDC, the American Association of Blood Banks, and any hospital that wants to volunteer to follow the rules and submit data on these events to the CDC.
So far, about 20-25 hospitals are participating, including about nine hospitals that launched the pilot project last year, says Barbee Whitaker, director of data and special programs for the AABB. "But 60-80 other hospitals have let us put their names on our Web site that they're going to join, and are in one phase or another of taking that step."
The hospitals follow protocol that includes a set of definitions that spell out specifically what constitutes each of 10 categories of transfusion reactions in their patients, and report them to the CDC. They can monitor their own statistics, but not those from other participating hospitals.
Some adverse reactions may be relatively minor, such as a rash, hives, flushing, edema or itching lasting hours or a few days. But reactions can be much more severe, including hypotension, fevers, bronchospasms, anaphylactic shock, renal failure, pain at the IV site, and abrupt onset Transfusion Related Acute Lung Injury, or TRALI.
There's also Acute Hemolytic Transfusion Reaction or AHTR, in which the body's antibodies cause a reaction that results in rapid destruction of red blood cells immediately after or within 24 hours of a transfusion or a delayed reaction, called DHTR, 24 hours to 28 days after the blood is given. Febrile Non-Hemolytic Transfusion Reaction, or FNHTR, Post Transfusion Purpura, or PTP, and Hypotensive Transfusion Reaction are also defined.
All of these can result in longer hospital stays, slower recoveries, and in a few very rare cases, death—reactions that some hospital officials may attribute not to the blood transfusion, but to the illness that caused the patient to be admitted in the first place. "We think that there's a lot of things that go wrong in blood transfusions that get misattributed," Whitaker says.
The effort also is trying to get hospital officials to keep track of human errors in the handling or labeling of blood that result in unintended consequences, such as Mrs. Jones getting blood intended for Mr. Smith, which may or may not result in adverse reaction to those patients.
"These may be considered near misses, in that they could have resulted in an adverse reaction if the circumstances had been different," Kuehnert says.
The actual number or percentage of such events occurring within the estimated 5.3 million U.S. patients transfused annually is unknown because for whatever reason, hospitals in this country have not organized an effort to count them as European countries have been doing for many years.
But a 2004 survey of 1,322 medical facilities reported 32,128 transfusion-related reactions that required diagnostic or therapeutic intervention, according to a report issued a year ago by the CDC.
"This is a new idea for the U.S." says James AuBuchon, MD, president-elect of the AABB, and president and CEO of the Puget Sound Blood Center in Seattle who has long pushed for an effort to count adverse events from transfusions. "Today, every developed country in the world has a hemovigilance system, and since earlier this year, the U.S. has finally joined them."
He adds that perhaps "there's been less of a drive to track this because it's not perceived as a big problem in the general patient population. In the grand scheme of things, it's not like [adverse] drug reactions, which happen far more frequently."
Now, the healthcare climate is changing, and any effort to reduce patient stays, improve care, and avoid paying for avoidable mistakes is assuming a greater priority.
Kuehnert says the field of blood safety has also been preoccupied for many years on keeping infectious disease agents out of the blood supply. "But we know that there's a whole university of other adverse events that are not infectious events."
One area the project is focusing on is a type of adverse event that is poorly understood. It occurs when a transfused patient suffers a minor or severe reaction because they were allergic to white cells that were included in red cell or plasma transfusions.
They can cause fever, chilling, shaking, unconsciousness, and other symptoms that require days of extra hospital stays, and, of course, more expense to the healthcare system. Each one may be more or less expensive to treat, Kuehnert says. "But if there are many of them it adds up to a burden of cost. We think that cost analysis can be very important, but it's something we won't know until we have the data from this project."
"In recent years, there's been an effort to reduce the number of white cells in products," a process known as "washing" or leukocyte reduction, which Kuehnert says "is universal" in European hospitals. But because of its substantial cost, it is done only in certain circumstances in the U.S. when certain patients are known to be at high risk of such reactions.
"I would compare it to a catheter infection," Kuehnert says. "It used to be that hospitals thought they were unavoidable, but then we got data to show that catheter events are preventable if you do certain things."
"Some patients we know are at increased risk, and as long as those patients are recognized, they will get irradiated components that will prevent them from coming down with graft versus host reactions. But there are some cases where the patient did not appear to be a risk; the immune system problem wasn't recognized," AuBuchon says.
"Are they preventable or not preventable? How frequently are they occurring. Maybe we can learn from it and try to prevent it."
"These are rare. And often, any one physician or hospital or any blood center would not see them often enough to connect the dots," AuBuchon says.
Katharine Downes, MD, a blood transfusion specialist at Case Western Reserve University, which was one of the first nine hospitals that participated in the project, says she was surprised at how decentralized record-keeping on adverse transfusion reactions had been. Before, she says, if she wanted information about a transfusion reaction, "I had to look in five different places." Now there's only one.
"What this protocol does is actually create these definitions, signs and symptoms, and lab findings, and it also provides a system to grade [the severity] of the adverse reactions," she says.
Whitaker of the AABB is excited about the project's potential. "There's a tremendous amount of information we're going to learn from this that we've not had the chance to look at before."