Decades ago, our blood bank system began disassembling units of donated blood, ushering in the era of component therapy. Now, it seems, we are seeing the light and starting to re-look at the concept of using fresh whole blood. To see the difference between fresh whole blood and “rebuilt” whole blood from components, read this post.

The military has a keen interest in studying the practice of using whole blood, since combat locations have a considerable number of “walking blood banks” (i.e. soldiers) . An abstract being presented tomorrow at EAST was submitted by the US Army Institute of Surgical Research. They performed a straightforward study looking at mortality in combat casualties, comparing troops who received fresh whole blood (FWB) to those who received component therapy (kind of). They used regression analysis to try to identify and control for other variables, and also analyzed a subgroup who required massive transfusion.

Here are the factoids:

• A total of 215 soldiers received FWB, and 896 did not. Of note, the non-FWB patients did not necessarily receive platelets.
• Overall, survival was similar in both groups at about 94%
• After controlling for physiologic injury severity and blood product/crystalloid volumes, the risk of death was twice as high in the group that did not receive FWB
• Survival was higher in FWB patients who underwent massive transfusion (89% vs 80%), although this was only marginally significant

Bottom line: I see this an an interesting but preliminary study, with many unanswered questions. It’s not really a comparison of patients receiving fresh whole blood vs component therapy, because not all of the latter patients received platelets. It also did not take into account the specific anatomic injury areas, particularly critical ones such as brain injury. But this study should certainly stimulate some better designed projects for followup.

Here are some questions for the authors to consider before their presentation:

• Did you do a power analysis to estimate how many patients would need to be enrolled to discover a real difference? If so, how many?
• Have you performed a subanalysis on patients in the non-FWB group who received platelets? This would then be a comparison of FWB vs component therapy.
• Any idea of the age of the components given vs the day 0 FWB?
• Be sure to show and interpret your significance testing in the presentation

Reference: EAST 2018 Podium paper #15.