Fresh unrefrigerated whole blood (FUWB) has been variously defined as blood collected at less than 4 hours (ultra-fresh),53 24 hours54 and 72 hours.55 Most published data concern FUWB stored at room temperature for less than 24 or 48 hours, but not less than 4 hours.54
FUWB may have a role in massive transfusion, without the potential for clinical sequelae from storage lesion. However, few well-conducted studies have investigated the efficacy or risks of using FUWB, and reports of its benefits have been largely anecdotal.
The use of FUWB has been advocated in cardiac surgery, burns and massive transfusion, particularly in the military setting.54,56,57 The potential role of FUWB in civilian settings has been extrapolated from the military experience.
A recent study of neonates undergoing cardiopulmonary bypass surgery reported improved clinical outcomes with reconstituted FUWB compared with stored blood components.58 However, other studies have reported conflicting results.59,60
The use of FUWB that has not been screened at the time of donation carries an increased risk of transmission of infectious agents. Additional potential risks of FUWB include ABO haemolysis and (if the product has not been irradiated) transfusion-associated graft-versus-host disease.
The use of FUWB is best limited to clinical trials and situations where there is life-threatening bleeding, and blood component therapy is unavailable.