International Forum on ‘Perioperative blood salvage’: a Spanish contribution

Abstract

We read with interest the conclusions of the International Forum on 'Perioperative blood salvage' published by Engelfriet & Reesink in a recent issue of Vox Sanguinis [1]. To obtain the relevant information on this alternative to allogeneic blood transfusion, the authors sent a 9-item questionnaire to experts in the field. They were able to obtain only six contributions to this Forum from investigators working at Germany, Austria, the Netherlands, and UK, and considered the answers of sufficient interest to warrant publication. Since 1986, our group (Multidisciplinary Autotransfusión Study Group, Spain) is conducting clinical and laboratory research in this field, especially in the elective orthopaedic surgery setting, and we would like to contribute to this Forum in regard to postoperative blood salvage. Questions 2 and 8. Indications and effectivenessWe found that postoperatively collected unwashed filtered shed blood after orthopaedic is safe and effective in reducing allogeneic blood transfusion requirements [2]. We retransfuse drained blood if a minimum of 400 ml are collected within the first six postoperative hours, and up to a maximum of 1000-1200 ml. However, the contribution of unwashed filtered shed blood return to allogeneic blood transfusion reduction decreases if a transfusion protocol is adopted. From these data it can be inferred that a transfusion protocol does in itself reduce by 25-30% the relative risk for allogeneic blood transfusion and, therefore, it must be the first strategy to include in a blood saving program [2].Questions 4 and 6. Removal of tissue and biochemical debris, leukocytes and platelets Blood processing devices are quite effective (> 95%) in removing chemical contaminants, whereas the removal of tissue debris, leukocytes and platelets is only partial. In contrats, tissue debris and cells in unwashed filtered shed blood are easily detected using a standard blood cytometer, and eliminated by filtration, whereas chemical contaminants (cytokines, heparin, plasma haemoglobin, etc.) are not [2]. However, in our experience, the return of unwashed filtered shed blood after orthopaedic surgery does not modify the postoperative acute phase response [3] or the postoperative cellular immune response [4]. In addition, unwashed filtered shed blood seems to contain factors with antiinflammatory properties [5]. Finally, we did not observe any clinically significant coagulation disorder or increase of postoperative infection rate after retransfusion of unwashed filtered shed blood [2]. These data question the need for processing postoperatively salvaged blood after orthopaedic surgery. Questions 5 and 7. Quality control and untoward reactionsWe do not routinely perform a quality control of this blood, except for a haematimetric analysis. In our experience, not clinically relevant untoward reactions were witnessed after the reinfusion of unwashed filtered shed blood [2][3][4][5]. However, we believe that, to meet with European Directives on transfusion safety, the elaboration of quality standa...