Unneeded hospital blood tests giving heart attack victims life-threatening anemia

Wednesday, August 10, 2011 by: S. L. Baker, features writer
Tags: blood tests, anemia, health news

(NaturalNews) It feels like a horrific tale about barbaric medical practices from ancient history: people with a life threatening heart condition are subjected to bloodletting until they become anemic. But this is no joke and it is happening right now. According to new research, hospitals are routinely subjecting heart attack patients to many excessive routine blood tests. These already seriously ill people are becoming sicker -- and may even die as a result.

These are the facts revealed in a new study just published in the Archives of Internal Medicine, one of the JAMA/Archives journals. It turns out that when someone has a heart attack, known by the medical term myocardial infarctions (MI), they are at increased risk for death and worse health in general if they are anemic. And a lot of them become anemic in the hospital.

So is this because having a heart attack sometimes causes some kind of internal bleeding, resulting in dangerous anemia? The answer is no. The anemia is usually the result of the actions of the hospital staff. The new research found that blood loss from the overuse of phlebotomy (blood drawn for diagnostic testing) is behind the development of hospital-acquired anemia (HAA).

Anemia, a condition in which the body does not have enough healthy red blood cells (hemoglobin), is associated with greater mortality and worse health status in patients with heart attacks. That makes sense when you consider that red blood cells provide oxygen to body tissues and a lack of oxygen places extra stress on the cardiovascular system. Symptoms of anemia include fatigue, weakness, irregular heartbeat, and shortness of breath.

Adam C. Salisbury, M.D., from Saint Luke's Mid America Heart and Vascular Institute in Kansas City, Mo., and his research team pointed out that HAA could mostly be prevented if strategies were implemented to reduce blood loss in high-risk patients. In other words, it's time to stop taking so much blood from heart attack victims for repeated and unnecessary tests that their health is worsened and their risk of dying is increased.

The researchers noted in a media statement that diagnostic phlebotomy has been associated in a variety of patient populations with in-hospital declines in red blood cell levels and even the need for blood transfusions. "Blood loss from phlebotomy could be an actionable target for intervention," write the authors.

Salisbury and colleagues analyzed data from the Cerner Corp.'s Health Facts database involving 17,676 patients who were admitted with heart attacks but no anemia from 57 hospitals. Then, in order to measure blood loss, the researchers identified how many times each patient had blood taken. They checked to see what specific lab tests were ordered and what size of hematology tubes were used for collecting blood.

For each patient, the researchers multiplied these blood volumes by the number of tubes of each type that were collected during the heart attack victims' hospital stays. In addition, they calculated the average blood drawn for every 24 hours of hospitalization as well as the average phlebotomy volumes for each of the first 10 days of hospitalization.

The results showed a whopping one in five of the heart attack patients developed moderate to severe anemia, due to blood loss from excessive hospital tests. In fact, estimates of the mean blood loss from phlebotomy for these patients made anemic in the hospital were almost 100 mL higher than estimated blood loss in patients who did not develop moderate to severe HAA the course of the hospitalization.

Just how much blood was taken from heart attack patients varied widely depending on what hospital was doing the tests. Overall, the relative risk for developing anemia from hospital tests increased by 18 percent for each 50 mL of blood drawn.

"In conclusion, blood loss from phlebotomy is substantial in patients with MI, varies across hospitals, and is independently associated with the development of HAA," write the authors. "Studies are needed to test whether strategies that limit both the number of blood draws and the volume of blood removed for diagnostic testing can prevent HAA and improve clinical outcomes in patients with MI."

In an accompanying editorial, Stephanie Rennke, M.D., and Margaret C. Fang, M.D., both from the University of California, San Francisco, call hospital-acquired anemia a hazard of hospitalization. "With the increasing evidence that health care system interventions can reduce or prevent many hospital-acquired complications, efforts to implement effective strategies to make medical care safer and more effective are crucial," they wrote.

"Investigations on how to modify this risk (e.g., through reducing unnecessary phlebotomy or reducing the volume of blood obtained during a hospitalization) could provide important insights into how to reduce anemia in the hospital and improve the value and appropriateness of care."

For more information:
http://archinte.ama-assn.org