STS News, Summer 2021 — The Society, along with three other leading medical specialty societies, recently released a new clinical practice guideline that includes recommendations for reducing blood loss during heart surgery and optimizing patient outcomes.
Since 2011—when the guideline was last updated—there has been a “remarkable increase” in minimally invasive procedures that has contributed to a favorable shift in blood product utilization and management, according to coauthor Victor A. Ferraris, MD, PhD, from the University of Kentucky College of Medicine in Lexington.
“Blood management guidelines are a ‘moving target’ that change with the advent of new or modified evidence,” he said.
As a result, the new comprehensive, well-researched document—a multidisciplinary collaboration among STS, the Society of Cardiovascular Anesthesiologists, the American Society of ExtraCorporeal Technology, and the Society for the Advancement of Patient Blood Management (SABM)—features 23 new or updated recommendations. This is the third iteration of the guideline on blood management and the first in 10 years.
“This guideline provides clinicians with a detailed assessment of patient blood management in the cardiac surgical patient—what has been proven to work and what has not, as well as the ability to incorporate these techniques with the most up-to-date evidence,” said lead author Pierre R. Tibi, MD, from Yavapai Regional Medical Center in Prescott, Arizona.
Patient-Centered Blood Management
It’s important to note that in previous guidelines, the term “blood conservation” was used; the new recommendations yield to the broader term “patient blood management” (PBM).
PBM—developed in 2008—is “the timely application of evidence-based medical and surgical concepts designed to maintain hemoglobin concentration, optimize hemostasis and minimize blood loss in an effort to improve patient outcomes,” according to SABM.
Based on a growing body of evidence published over the years (much of which was reviewed by the writing committee), PBM has moved away from simply reducing the use of blood components and now focuses more on developing multidisciplinary and multimodal strategies centered on patient outcomes.
The major tenets of PBM, which are confirmed in this guideline, are:
Managing anemia
Minimizing blood loss
Reducing the need for allogeneic blood transfusions
This approach also places patients at the heart of the decision-making process, helping to ensure that they are fully informed of the risks and benefits of their treatments and that their values and choices are incorporated into the treatment pathway.
“As medicine evolves and we learn more, it always is important to review past assumptions, validate new information, and concisely present the best current recommendations,” said senior author Susan D. Moffatt-Bruce, MD, PhD, MBA, from the Royal College of Physicians and Surgeons of Canada in Ottawa. “These recommendations are really centered on the patient and how they would want to be treated during complex cardiothoracic procedures.”
Blood Is a ‘Liquid Organ’
Among the most important changes to the practice guideline is the adoption of PBM as a treatment of the whole patient, with blood considered a “liquid organ” or “vital entity” in taking care of the surgical patient, rather than focusing simply on when or when not to transfuse, explained Dr. Tibi.
Blood transfusions—which can be a critical and life-saving facet of cardiothoracic surgery patient care—date back to the 17th Century when British physician William Harvey, MD, discovered the circulation of blood and attempted the first blood transfusion.
In the hundreds of years since, the practice has certainly evolved, being proven generally safe and saving millions of lives. However, it does carry the risk of serious side effects, according to Dr. Tibi. With the potential to introduce disease and cause potent immunological reactions or even death, transfused blood does not work as well as a patient’s own blood.
“Blood transfusions can be harmful to the body. Therefore, unless the proven benefit of blood transfusions outweighs the known risks, it is better to treat patients before, during, and after surgery in ways that decrease the risks of needing blood as much as possible for the best outcomes,” he said.
These risks can be lessened through the use of PBM, by safeguarding the patient’s own blood and ensuring transfusions are not needed. In fact, some hospital systems in the US have experienced as much as a 45% overall reduction in the rate of transfusions since starting PBM programs.
“Patient safety is well supported in this guideline, as it reduces the risks associated with blood transfusions,” said Dr. Moffatt-Bruce.
Avoiding Blood Transfusions
For example, the guideline includes preoperative interventions related to identifying and managing anemia, which is “extremely prevalent” in the cardiac surgical population, especially in elderly patients or those with multiple comorbidities and chronic diseases.
The most common cause of anemia is iron deficiency, occurring in up to 50% of anemic patients, according to the guideline. Historically, patients with preoperative anemia are more likely to require transfusions, so treating iron-deficiency anemia should be done before surgery. If successful, this can dramatically reduce the need for a blood transfusion.
The new guideline also suggests that in cardiac operations with cardiopulmonary bypass, the “well-established method” of red cell salvage via centrifugation may be routinely used. Red cell salvage is an important part of the blood conservation aspect of PBM.
Another new addition to the guideline is the recommendation to administer human albumin after cardiac surgery, which also has been shown to minimize the need for transfusion. Also, retrograde autologous priming should be used wherever possible, according to the guideline. This simple, safe, and effective process has been shown to decrease transfusion rates, especially for cardiac operations that result in excessive blood loss.
“The guideline has been assembled by experts from different specialties and backgrounds who have reviewed the most recent data,” said Dr. Moffatt-Bruce. “This guidance allows clinicians to standardize treatment with the knowledge that they are utilizing the best information while considering all aspects of patient care.”
Dr. Tibi expects that some clinicians will be surprised by several of the recommendations, especially those that carry a “great deal of evidence” and likely will require changes to routine treatments for their patients undergoing cardiac surgery (e.g., the information related to the preoperative treatment of anemia and the assorted perfusion techniques).
For patients, it’s important that their hospitals, surgeons, and care teams are aware of PBM and that they are utilizing the “best, most proven techniques available,” Dr. Tibi advises. “Patients should certainly ask, ‘What do you do so that my chances of receiving blood are minimized?’”
In developing this guideline and identifying relevant evidence, a systematic review was outlined and extensive literature searches were conducted by a workgroup. The group then wrote and developed recommendations based on the critical appraisal of approximately 90 highly cited articles included in the final review.
The guideline is available at annalsthoracicsurgery.org.
