UMEM Educational Pearls

Historically, guideline recommendations have been to use a transfusion threshold of hemoglobin < 7 g/dL for patients unless they are a) undergoing orthopedic surgery or b) have cardiovascular disease (CVD).  

Applefeld et al conducted a meta-analysis in 2018 which suggested that restrictive (i.e. lower hemoglobin trigger, typically 7-8) transfusion targets lead to worse outcomes in CVD patients than liberal (i.e. higher hemoglobin trigger, typically 9-10) targets, and those authors have updated this analysis to include data from newer trials.  Interestingly, the conclusion remains similar: that when you look at the larger studies on restrictive vs liberal transfusion targets, CVD plays an important role, as patients with CVD tend to do better with liberal targets, and patients without CVD tend to do better with restrictive targets.  Of note, CVD is variably defined in these studies, and sometimes limited only to active Acute Coronary Syndromes, and other times refers to all patients with acute or chronic CVD.  However, according to their analysis, the aggregated data suggests that we should continue having higher transfusion targets in patients with CVD, and perhaps even more in the 9-10 range, as opposed to the goals of 7 or 8 which are common.

Bottom Line: We will likely continue to see different transfusion targets recommended for patients with cardiovascular disease (CVD), and may even see guideline and blood bank recommendations raise the target for these patients more into the 9-10 range, or expand this group to include chronic CVD.  This would mean a substantial increase in recommended RBC transfusions, and as emergency physicians it is important for us to monitor these recommendations, especially since transfusions are not harmless and raising hemoglobin thresholds could lead to complications that are difficult to measure in the literature.