We’ve done numerous columns over the years about the increasing evidence that more restrictive criteria for transfusions do not lead to worse outcomes for many or even most patient conditions and that transfusions may be associated with a variety of potential adverse effects. The AABB (American Association of Blood Banks) updated its guidelines on transfusion in 2012 (see our April 2012 What's New in the Patient Safety World column “New Transfusion Guidelines from the AABB”) to reflect the trending literature. Now the AABB has once again updated its transfusion guidelines after reviewing the updated literature for randomized controlled trials (RCT’s) dealing with transfusion criteria (Carson 2016).
The updated AABB guideline recommends two tiers of hemoglobin level transfusion triggers:
The guidelines do not include any recommendations regarding patients with acute coronary syndromes, severe thrombocytopenia, or chronic transfusion–dependent anemia.
Interestingly, one point brought out in the discussion is that "standard practice should be to initiate a transfusion with 1 unit of blood rather than 2 units. This would have potentially important implications for the use of blood transfusions and minimize the risks of infectious and noninfectious complications”. That is of interest because one of the triggers historically used by transfusion committees to review cases for appropriateness was the use of a single unit of packed RBC’s rather than at least two units.
The other new recommendation has to do with the freshness of the RBC’s. It states that patients, including neonates, should receive RBC units selected at any point within their licensed dating period rather than limiting patients to transfusion of only fresh (storage length: <10 days) RBC units.
The Carson article also includes the evidence summary and has a nice table summarizing the odds of the various adverse effects of RBC transfusions.
In an accompanying editorial (Yazer 2016) Yazer and Triulzi remind us that good clinical practice dictates that the decision to transfuse should not be solely based on the hemoglobin level. They suggest that future studies look at inclusion of some sort of measure of tissue oxygenation to aid in the clinical decision about transfusion.
The Carson article includes the following Good Clinical Practice Statement: “When deciding to transfuse an individual patient, it is good practice to consider not only the hemoglobin level, but the overall clinical context and alternative therapies to transfusion. Variables to take into consideration include the rate of decline in hemoglobin level, intravascular volume status, shortness of breath, exercise tolerance, lightheadedness, chest pain thought to be cardiac in origin, hypotension or tachycardia unresponsive to fluid challenge, and patient preferences. This practice guideline is not intended as an absolute standard and will not apply to all individual transfusion decisions.”
Prior columns on potential detrimental effects related to red blood cell transfusions:
Carson JL, Guyatt G, Heddle NM, et al. Clinical Practice Guidelines from the AABB. Red Blood Cell Transfusion Thresholds and Storage. JAMA 2016; Published online October 12, 2016
Yazer MH, Triulzi DJ. AABB Red Blood Cell Transfusion Guidelines. Something for Almost Everyone. JAMA 2016; Published online October 12, 2016