Clinical practice guidance released today outline recommendations for reducing blood loss during cardiothoracic surgery and improving patient outcomes. The document, a multidisciplinary collaboration among The Society of Thoracic Surgeons (STS), the Society of Cardiovascular Anesthesiologists (SCA), the American Society of ExtraCorporeal Technology (AmSECT), and the Society for the Advancement of Patient Blood Management (SABM), is available online in The Annals of Thoracic Surgery and two other journals.
“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, from the Royal College of Physicians and Surgeons of Canada, Ottawa, Canada. “These recommendations are really centred on the patient and how they would want to be treated during complex cardiothoracic procedures.”
Since the last update of the guidance in 2011 there has been a “remarkable increase” in minimally invasive procedures that has contributed to a favourable shift in blood product utilisation and management, according to co-author Victor A Ferraris, from the University of Kentucky College of Medicine, Lexington, USA. As a result, the new practice guideline, which features 23 new or updated recommendations, marks the third iteration and the first in 10 years. “Blood management guidelines are a ‘moving target’ that change with the advent of new or modified evidence,” he said.
Unlike in the previous guideline, which used the term “blood conservation”; the new recommendations yield to the broader term “patient blood management” (PBM). PBM—developed in 2008—is a standard of care designed to optimise patient outcomes by minimising blood loss, preventing anaemia, and reducing the need for allogeneic blood transfusions. This approach also places patients at the heart of the decision-making process, ensuring that they are fully informed of the risks and benefits of their treatments and incorporating their values and choices into the treatment pathway, according to the authors of the guideline.
“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, from Yavapai Regional Medical Center, Prescott, USA.
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, says Tibi.
“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.
Risks can be lessened through the use of PBM, to ensure that a patient’s own blood is adequate and transfusions are not needed.
“Patient safety is well supported in this guideline, as it reduces the risks associated with blood transfusions,” adds Moffatt-Bruce.
The guideline includes preoperative interventions related to identifying and managing anaemia. The most common cause of anaemia is iron deficiency, occurring in up to 50% of anaemic patients, according to the guideline. Historically, patients with preoperative anaemia are more likely to require transfusions, so treating iron-deficiency anaemia should be done before surgery. If successful, this can dramatically reduce the need for a blood transfusion, the guidelines suggest.
The new guidelines also suggest that in cardiac operations with cardiopulmonary bypass (CPB), the “well-established method” of red cell salvage via centrifugation may be routinely used. In this process, blood that the patient loses during the operation is collected, filtered, and washed by a machine before being reinfused into the patient.
Another new addition to the guideline is the recommendation to administer human albumin after cardiac surgery, which also has been shown to minimise the need for transfusion, the authors suggest. This medicine typically is used to treat or prevent shock following serious injury, bleeding, or surgery by increasing the volume of blood plasma. Also, priming of the CPB circuit with a patient’s own blood (known as “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 Moffatt-Bruce. “This guidance allows clinicians to standardise treatment with the knowledge that they are utilising the best information while considering all aspects of patient care.”
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.