Resumen
We have performed a series of studies over the course of a decade with a large animal model of shock and meta-analysis techniques to study transfusion trials. Although clinical trials have established the safety of the current practice of transfusing 18- to 22-day-old stored blood, observational studies have suggested that the oldest units (aged 35?42 days) when transfused have increased risks. These risks are dependent on host factors. Transfused older blood has increased hemolysis with the release of cell free hemoglobin (CFH) and iron. Subjects with infection may be harmed by transfusing iron which promotes bacterial growth. In situations where nitric oxide (NO) is important, such as coronary disease, CFH scavenging of NO may increase risk to patients.