Intraoperative salvage of small volumes of shed blood

Modern autotransfusion devices have made intraoperative auto-transfusion of small volumes above approximately 100 ml of shed blood technically feasible, resulteting in packed red blood cells of high quality. For this indication, continuously working systems, conventional autotransfusion devices with specially designed small volume bowls, and machines with a dynamically adapting separation chamber can be used. In adults, however, washing less than 600 - 800 ml of shed blood (haematocrit 0.25 - 0.30) will help to avoid allogeneic blood transfusions only occasionally. The anaesthetist should not be guided by strict limiting values, but has to consider initial haemoglobin concentration, transfusion trigger, expected postoperative blood loss and, above all, both haematocrit and volume of shed blood as well as institutional resources and other factors. Collecting shed blood in a reservoir filter seems to be advisable whenever intraoperative blood loss cannot clearly be predicted. Additional processing of drainage blood in the early postoperative period can be considered in certain operations (e.g. total knee arthroplasty).