Drawing patients' blood may not be something that most hospitalists put a lot of thought into. Whether by routine protocol or specific order, many, many blood draws are made over the course of the day in the hospital.
“Physicians often have no idea of the magnitude of the amount of blood that we take for laboratory tests. We often order these tests and don't think about the cumulative effect,” said Adam C. Salisbury, MD, a researcher and cardiology fellow at the University of Missouri-Kansas City.
Based on new research by Dr. Salisbury and colleagues, physicians may want to start being a little more thoughtful about their blood draws, however. The researchers found a clear association between diagnostic phlebotomy and hospital-acquired anemia (HAA) in patients hospitalized with acute myocardial infarction (MI), in a study published in the October 2011 Archives of Internal Medicine.
One in five patients in the study who did not have anemia when first hospitalized with acute MI subsequently developed moderate to severe anemia in the hospital. Diagnostic blood loss was substantial among the patients who developed HAA. Their mean estimated phlebotomy was 173.8 mL, equivalent to about half a unit of whole blood; 12% of patients had more than 300 mL of blood drawn while they were in the hospital, and nearly 4% had at least 500 mL drawn.
Dr. Salisbury and colleagues had previously found anemia to be associated with worse health status after MI, including higher mortality (in a study in the July 2010 Circulation: Cardiovascular Quality and Outcomes), but physicians had generally assumed that the association resulted from patients being treated with anticoagulants or undergoing invasive procedures. However, in that publication they found that anemia was common in patients who did not experience bleeding events.
So it was significant when the new study, which excluded patients who had undergone coronary bypass grafting, concluded that every 50 mL of blood drawn increased the risk of anemia by about 18%.
And patients with acute MI are not the only ones at risk of developing HAA. “When we bring patients into the hospital, drawing blood every day is the one thing we do uniformly—not only in heart attack patients but in all medical patients,” said Dr. Salisbury.
Patients most at risk of anemia include the elderly and those with kidney disease, heart failure, chronic lung disease, and pneumonia, he added. They are also often the same patients who have the longest hospital stays and are exposed to more blood draws, Dr. Salisbury said.
The good news is that hospitalists can do something about this problem with little expenditure of hospital resources. “There can be good reasons to draw blood every day, but there are also some things we can do to reduce the amount of blood we take,” Dr. Salisbury said.
Minimizing HAA risk
Several hospitals have already implemented procedures for reducing the amount of blood drawn and thereby the risk of HAA. The University of California San Francisco Medical Center has established a protocol at its Mt. Zion and Moffitt-Long hospitals aimed at reducing the expense associated with daily blood draws, a move that is also reducing the quantity of blood lost by patients.
Before, physicians on the medical services at those hospitals typically would request a complete blood count for each day a patient was hospitalized, according to Stephanie Rennke, MD, an assistant clinical professor in the department of hospital medicine. Now that type of order cannot be automatically entered into the system. Instead, the physician must decide each day whether to order a blood test, prompting a reevaluation about what that patient needs.
Responsibility for adherence to the protocol extends throughout several departments. If a clinician writes an order for daily blood work despite the protocol, the unit clerk or the person who transcribes the order must remind the physician about the protocol.
Dr. Rennke noted that HAA is a problem that has been relatively hidden because hospitalized patients often have other issues that demand more immediate attention. “In the hospital, it comes down to prioritization, what needs to be done right away. But HAA is as much of an issue and should be as much in the forefront of discussion as prevention of hospital-acquired infections or falls or pressure ulcers, which are all very important,” she said.
The Cleveland Clinic has taken another approach to the problem. There it is now standard in most ICU and general medicine areas to use smaller containers for blood collection, in order to reduce blood waste.
In addition, the hospital's electronic health record (EHR) system has been modified so that if a physician orders a blood test that requires large quantities of blood collection, the system will show whether that test was previously done and the results. If a physician decides to order the test again, that order will be scrutinized and possibly questioned by the lab. Prior to this modification, the electronic system “had no stop sign about ordering multiple blood tests. It just allowed you to order as many blood tests as you wanted. That was the default system,” said Ajay Kumar, MD, FACP, former medical director of blood management at the Cleveland Clinic.
Now, as chief of the division of hospital medicine at Hartford Hospital in Connecticut, Dr. Kumar is collecting data about blood utilization there, and looking for opportunities to reduce waste and over-collection, with an eye toward establishing practices that promote conservation. Hartford Hospital already has one important check in place: The EHR system defaults to a limited number of blood orders. Unless a physician actively requests frequent blood tests, they are done only a limited number of times.
The next step, Dr. Kumar said, will be building an alert into the EHR about whether the tests ordered by physicians—and the frequency of them—are clinically required.
Although Dr. Salisbury's hospital, St. Luke's Mid-America Heart Institute, does not have a formal protocol for HAA prevention, several interventions to reduce diagnostic blood loss are currently being studied and several physicians there use smaller tubes for smaller blood draws instead of the standard-sized tubes, he reported. “We have found that the smaller tubes are compatible with our existing equipment and that we can run the same lab tests and get the same things done with a smaller blood sample,” Dr. Salisbury said.
His hospital also has a system that encourages physicians to run their labs on stored serum, rather than requesting a new blood draw each time a new service evaluates a patient. A prospective study is underway to compare this existing voluntary practice, where interested physicians use smaller tubes and stored serum, with a standardized protocol that will request that all physicians use smaller tubes, use stored serum samples, and batch the blood draws. “We have an intervention that is likely to work—smaller tubes, batched samples, stored serum—and that really doesn't cost anything for hospitals but requires a more uniform application. This intervention could clearly benefit patients,” Dr. Salisbury said.
St. Luke's Mid-America Heart Institute is also taking a more proactive role in monitoring for anemia, trying to identify patients who are at high risk when they are admitted and alerting staff to be vigilant about the amount of blood that is drawn. Other strategies they use to reduce HAA include identifying previously unrecognized iron deficiencies and trying to reduce the amount of bleeding during procedures, for example, by using anticoagulant regimens known to reduce risk of bleeding or taking a radial rather than groin approach for coronary angiography in high-risk patients, Dr. Salisbury said.
The role of hospitalists
Hospitalists may be the ideal candidates to take a leadership role in finding ways to prevent HAA, according to the experts. “Hospitalists are uniquely positioned to effect change,” Dr. Rennke said. “[They] many times are in leadership positions and are in direct communication with individuals who can help implement these systems to make them happen.”
Hospitalists are not only critical to initiating changes in the institution's systems and procedures, they can help deploy these interventions across all hospital settings, according to Dr. Salisbury. “At our hospital, it is the hospitalists who have been the earliest and most aggressive adopters of these interventions for reduced blood loss,” he said. “They have been more likely to request smaller tubes for their patients and to request that blood they are ordering be added to stored serum when appropriate. To get these efforts generalized to the rest of medical patients in the hospital—and even to surgical patients—the hospitalists are critical.”
Dr. Kumar credits his experience as a hospitalist to his understanding of hospital systems—and ways they can be changed. The convenience of an electronic medical record, for example, made it easy to make multiple requests for blood testing and blood products. “Being a hospitalist [at the Cleveland Clinic], I was able to understand how systems that make our lives easier actually can lead to more waste,” he said. “Hospitalists are such heavy users of the system, we understand the pitfalls and issues better than anyone else,” he said.
As such, it is hospitalists who must get involved in changing these systems, Dr. Kumar added. “They are the ones well-suited to understand the appropriateness of resources and the need to cut down on waste,” he said.
Hospitalists' experience with multidisciplinary cooperation can also be helpful, since anemia prevention efforts need to include “not only the physicians who practice at the bedside but also the physicians in the lab who can help us know how small we can make our tubes and still use them with existing analytic equipment,” Dr. Salisbury said.
“HAA is a modifiable problem where the solutions might not increase costs to hospitals and will certainly be a win for patients,” he said. “Hospitalists are critical to this effort.”