Transfus Apher Sci
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We review the experimental evidence showing systemic and microvascular effects of blood transfusions instituted to support the organism in extreme hemodilution and hemorrhagic shock, focusing on the use of fresh vs. stored blood as a variable. The question: "What does a blood transfusion remedy?" was analyzed in experimental models addressing systemic and microvascular effects showing that oxygen delivery is not the only function that must be addressed. ⋯ It is concluded that fresh RBCs are shown to be superior to stored RBCs in transfusion, however increased oxygen affinity may be a positive factor in hemorrhagic shock resuscitation. Although experimental studies seldom reproduce emergency and clinical conditions, nonetheless they serve to explore fundamental physiological mechanisms in the microcirculation that cannot be directly studied in humans.
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Randomized Controlled Trial Multicenter Study
Addressing the question of the effect of RBC storage on clinical outcomes: the Red Cell Storage Duration Study (RECESS) (Section 7).
The question of whether storage of red blood cells (RBCs) alters their capacity to deliver oxygen and affects patient outcomes remains in a state of clinical equipoise. Studies of the changes which occur while RBCs are stored have led to several physiologically plausible hypotheses that these changes impair RBC function when the units are transfused. Although there is some evidence of this effect in vivo from animal model experiments, the results of several largely retrospective patient studies have not been consistent. ⋯ The primary outcome is the change in the Multiple Organ Dysfunction Score (MODS), a composite measure of multiorgan dysfunction, by day 7. Secondary outcomes include the change in the MODS by day 28, all-cause mortality, and several composite and single measures of specific organ system function. The estimated total sample size required will be 1434 evaluable subjects (717 per arm).