New AABB Guidelines Recommend More Restrictive Guidelines on Red Blood Cell Transfusion

11-7-23 (by: Scott Gleason) The American Association of Blood Banks (AABB) has published new guidelines on red blood cell transfusion, a widely used procedure in healthcare. The goal of these new recommendations is to assist healthcare providers in making informed decisions regarding red blood cell transfusions while considering patient well-being and the potential for adverse effects. Risks of red blood cell transfusions include an immunogenic allergic reaction, hemolytic reactions, and the transmission of infectious diseases. The new recommendations provide for a more judicious use of red cell components in transfusion citing similar patient outcomes for anemic patients that did and did not receive transfusions.

The recommendations emerge from a comprehensive evidence review. The guideline development process also addresses potential conflicts of interest, emphasizes transparency in articulating values and preferences, and relies on systematic reviews of randomized controlled trials. For adult patients, the guidelines highlight 45 randomized controlled trials encompassing over 20,000 participants. These trials compared restrictive hemoglobin-based transfusion thresholds, typically in the range of 7 to 8 g/dL, with more liberal thresholds of 9 to 10 g/dL. The evidence review indicates that, for most patient populations, following restrictive transfusion thresholds does not negatively impact patient-important outcomes and are recommended.

Consequently, the new guidelines recommend that for hemodynamically stable adult patients a restrictive transfusion strategy is incorporated. Transfusion is suggested when the hemoglobin concentration falls below 7 g/dL. In specific cases such as cardiac surgery, a threshold of 7.5 g/dL may be considered, while for orthopedic surgery or individuals with preexisting cardiovascular disease, a threshold of 8 g/dL can be applied.

For hospitalized adults with hematologic or oncologic disorders, a conditional recommendation was also made for a more restrictive transfusion strategy in this group. Transfusion is suggested when the hemoglobin concentration is less than 7 g/dL, although this recommendation is supported by low-certainty evidence.

The guidelines strongly recommend a restrictive transfusion strategy for hemodynamically stable children. For children with heart conditions, a transfusion threshold based on the specific cardiac abnormality and stage of surgical repair. Recommendations include 7 g/dL for biventricular repair, 9 g/dL for single-ventricle palliation, and 7 to 9 g/dL for uncorrected congenital heart disease. However, this recommendation is based on low-certainty evidence.

AABB believes the new guidelines will empower healthcare professionals to weigh the benefits and potential harms of transfusion, considering patient-specific factors that may influence the appropriate approach. Lower transfusion volumes could impact companies levered to blood transfusion such as companies that provide diagnostic tests for blood typing or infectious disease testing, companies that provide blood collection systems such as Haemonetics and Fenwal, and companies that offer pathogen inactivation technologies such as Cerus.