[Evaluation of efficacy of maximum surgical blood order schedule (MSBOS) in the operating room]

We evaluated efficacy of maximum surgical blood order schedule (MSBOS) using analysis of cross-match to transfusion ratio (C/T ratio) during 1 year after applying MSBOS to operations in our operating room. The MSBOS used was based on our trial reported in 1990. Compared with preoperative prepared blood units before application of MSBOS, C/T ratio decreased from 4.76 to 3.44, and cross matched blood units decrease from 476 units to 344 units (about 72%) per 100 packs of transfused blood. We conclude that application of MSBOS is effective and useful for saving preoperative prepared blood. Analysis with C/T ratio was very useful to recognize the present status of preparations of blood for surgery preoperatively. MSBOS should be re-evaluated regularly because of changes of operative environment such as surgeon, operative method, preoperative condition of patients, and so on.