Health & Medicine - Posted by Stephanie Desmon-JHU on Wednesday, April 25, 2012 11:44 - 1 Comment
More blood may amp surgery cost and risk
JOHNS HOPKINS (US) — Surgical patients often get expensive, potentially risky blood transfusions they don’t need, in part because of a lack of clear guidelines, researchers say.
Overuse of transfusions is a problem, they say, because blood is a scarce resource and because recent studies have shown that surgical patients do no better, and may do worse, if given blood prematurely or unnecessarily.
Straight from the Source
“Transfusion is not as safe as people think,” says Steven M. Frank, leader of a study described in the journal Anesthesiology.
“Over the past five years, studies have supported giving less blood than we used to, and our research shows that practitioners have not caught up,” says Frank, associate professor of anesthesiology and critical care medicine at the Johns Hopkins University School of Medicine.
“Blood conservation is one of the few areas in medicine where outcomes can be improved, risk reduced, and costs saved all at the same time. Nothing says it’s better to give a patient more blood than is needed.”
The concern about overuse does not apply, Frank says, to cases of trauma, hemorrhage or both, where infusing blood quickly can be lifesaving.
General guidelines from three different medical societies govern when a surgical patient should get blood, but tend to be imprecise, Frank says. In a healthy adult, a normal hemoglobin level—the quantity of red blood cells carrying oxygen through the body—is roughly 14 grams per deciliter of blood.
The guidelines state that when hemoglobin level falls below 6 or 7 grams per deciliter, patients will benefit from transfusion; if levels are above 10, a patient does not need blood. But when readings are in between, there has been little consensus about what to do.
Recent studies, Frank says, suggest that physicians can safely wait until hemoglobin levels fall to 7 or 8 before transfusing, even in some of the sickest patients.
In their study, Frank and his colleagues examined anesthesia records of more than 48,000 surgical patients at the Johns Hopkins Hospital over the 18 months from February 2010 to August 2011. Overall, 2,981 patients (6.2 percent) were given blood transfusions during surgery. The researchers found wide variation among surgeons and among anesthesiologists, compared to their peers, as to how quickly they order blood.
For example, patients undergoing cardiac surgeries received blood at much lower trigger points compared to patients having other surgeries. Patients undergoing surgery for pancreatic cancer, orthopedic problems, and aortic aneurysms, on the other hand, received blood at higher trigger points, often at or above 10 grams per deciliter.
The amount of blood transfused, Frank says, did not clearly correlate with how sick the patients were or with how much blood is typically lost during specific types of surgery. Blood is lost during many operations, though hemoglobin levels don’t often fall to the point where blood transfusion is necessary, he says.
Blood transfusion introduces a foreign “transplant” into the body, initiating a series of complex immune reactions. Patients often develop antibodies to transfused red blood cells, making it more difficult to find a match if future transfusions are needed.
Transfused blood also has a suppressive effect on the immune system, which increases the risk of infection, including pneumonia and sepsis, Frank says. He also cites a study showing a 42 percent increased risk of cancer recurrence in cancer surgery patients who receive transfusions.
Blood is in short supply and expensive, Frank says. It costs $278 dollars to buy a unit of blood from the American Red Cross, for example, and as much as $1,100 for the nonprofit to acquire, test, store, and transport it. Medicare pays just $180 for that unit of blood.
The decision about when to give a blood transfusion during surgery is made jointly by the surgeon and the anesthesiologist; the anesthesiologist administers the blood, Frank says.
After Frank presented his research to the department of surgery, the department director told the surgeons that although most of them were trained to transfuse when hemoglobin levels fall below 10, transitioning to a trigger of 7 or 8 made sense.
“A lot of our practices are just handed down through the generations,” Frank says.
Although Frank’s study focuses only on one hospital, he says the lack of consistent guidelines for ordering blood puts patients at risk all over the country.
Coming up with an exact algorithm for blood transfusion is impossible, as each situation and each surgery is different. But Frank believes that what is best for patients is to strive to transfuse less whenever possible.
More news from Johns Hopkins: http://releases.jhu.edu