The potential role of oxygen-carrying products in autologous blood transfusion protocols.

For surgical patients transfusion of autologous blood (AB) is the most useful of measures to reduce patient's exposure to homologous blood (HB). In our Institute an autotransfusion program was started in 1982 utilizing all the autotransfusion techniques currently available. The integrated use of the techniques offered to the majority of the patients the possibility of receiving AB (98% of the elective surgery patients) and a consistent conservation of HB has been achieved (60-70%). However 42% are still exposed to some HB. Critical parameters that render the patients unable to fulfill the anticipated transfusion needs with the current AB transfusion techniques are: the patient's ability to predonate sufficient AB prior to surgery and the amount of blood transfused intraoperatively that in turn depends on different "transfusion trigger". In our Institute over 50% of all the blood units are transfused the day of operation (60% being AB, 40% HB) and 50% postoperatively (only 33% being AB). For this reason, a clinical application for the oxygen-carrying products can be the replacement of the blood lost during, or immediately after the operation permitting the surgeon to operate safely at a lower Hct levels, thereby delaying the transfusion of blood and saving the AB obtained.