Perspective:

The following are 10 points to remember summarizing guidelines from the AABB (formerly the American Association of Blood Banks) for the administration of blood products to stable adults and children based on results from a systemic review encompassing 6,264 patients (19 trials).

1. Transfusion thresholds for the administration of red blood cells (RBCs) to patients are highly variable in clinical practice, but the AABB found little evidence to suggest benefit from liberal use of RBC transfusions.

2. Based on the results of three large randomized trials, RBC transfusions should be considered at a hemoglobin threshold of ≤7g/dl in stable patients in the intensive care unit.

3. In surgical patients, the threshold for transfusion is a hemoglobin ≤8 g/dl or for symptoms (chest pain, hypotension, etc.).

4. In the meta-analysis, mortality risk was nonsignificantly lower (relative risk [RR], 0.85 [0.7-1.03]) in those with restricted transfusions. The AABB argues that the trial results support absence of harm from restricted transfusions. Comments on power to assess harm were not provided.

5. In patients with cardiovascular disease, trial heterogeneity was significant. Trials (FOCUS and TRICC) with coronary artery disease (CAD) patients have not shown benefit (some studies trended toward harm) with a more liberal transfusion strategy, but some studies have demonstrated increased risk for myocardial infarction. Overall, the AABB feels a transfusion threshold of ≤8 g/dl is reasonable for patients with CAD who are stable, but symptomatic (e.g., chest pain, hypotension, tachycardia).

6. In patients with an acute coronary syndrome, the AABB does not have sufficient data to provide recommendations.

7. The AABB could not provide recommendations regarding transfusions in the setting of symptomatic anemia that does not surpass the above thresholds.

8. If a restrictive transfusion policy was followed, patient transfusion exposure would decrease an average of 40% (RR, 0.6 [0.52 = 0.72]).

9. None of these above recommendations apply to patients who are clinically unstable.

10. The AABB is calling for clinical trials to be undertaken to better assess transfusion thresholds, risks, and benefits of the current recommendations.