Restrictive blood transfusion strategy recommended
MedWire News: The AABB (formerly known as the American Association of Blood Banks) recommends a restrictive red blood cell (RBC) transfusion strategy for most patient populations, in new guidelines published in the Annals of Internal Medicine.
The guidelines provide a "strong recommendation" based on "high-quality" evidence that physicians should consider transfusion at hemoglobin concentrations of 7 g/dL or less in adult and pediatric intensive care unit patients.
In postoperative surgical patients, transfusion should be considered at a hemoglobin concentration of 8 g/dL or less, or when patients are displaying symptoms such as chest pain, orthostatic hypotension, or tachycardia unresponsive to fluid resuscitation, or congestive heart failure.
"Our recommendation is based on the evidence that restrictive transfusion is safe and associated with less blood use [than liberal transfusion]," write Jeffrey Carson (UMDNJ-Robert Wood Johnson Medical School, New Brunswick, New Jersey, USA) and co-authors.
They explain that although approximately 85 million units of RBCs are transfused annually worldwide, transfusion practices vary widely.
To determine optimal use of RBCs to maximize clinical outcomes and avoid the harms and costs of unnecessary transfusions, the AABB conducted a systematic review of randomized clinical trials evaluating transfusion thresholds published from 1950 to 2011.
A panel of 20 experts examined the proportion of patients who received any RBC transfusion and the number of RBC units transfused to describe the effect of restrictive transfusion strategies on RBC use.
To determine the comparative outcomes of restrictive and liberal transfusion strategies, they examined overall mortality, nonfatal myocardial infarction, cardiac events, pulmonary edema, stroke, thromboembolism, renal failure, infection, hemorrhage, mental confusion, functional recovery, and length of hospital stay.
Based on the evidence, the panel also suggests adhering to a restrictive strategy in hospitalized patients with pre-existing cardiovascular disease and considering transfusion for patients with symptoms of anemia or a hemoglobin level of 8 g/dL or less.
For hospitalized hemodynamically stable patients with acute coronary syndrome, there was insufficient evidence to recommend either a liberal or restrictive transfusion threshold.
Finally, the panel suggests that, although physicians most commonly use hemoglobin concentration to decide when to transfuse, symptoms of anemia should also be taken into account when making such decisions.
Carson and co-authors conclude: "We believe these guidelines provide a carefully considered set of recommendations that incorporate the quality of the evidence, benefits and risks of transfusion, and joint judgment of an expert panel from many subspecialties."
By Laura Cowen