INTRAOPERATIVE AUTOTRANSFUSION IS ASSOCIATED WITH MODEST REDUCTION OFALLOGENEIC TRANSFUSION IN PROSTHETIC HIP-SURGERY

Background: The efficacy of intraoperative salvage and washing of woun d blood and the predictors of allogeneic red cell transfusions in pros thetic hip surgery are insufficiently known. Methods: In 96 patients, undergoing primary or revision surgery, salvaged and washed red cells and, if necessary, allogeneic blood were used to keep haematocrit not lower than 33%. The bleeding of red cells during hospital stay was cal culated from the red cell balance. The preoperative red cell reserve ( millilitres of red cells in excess of a haematocrit of 33%) was estima ted and the difference between this volume and the total bleeding of r ed cells was retrospectively used to classify patients with regard to the need for red cells. Stepwise regression analysis was used to defin e patient-related variables associated with allogeneic blood transfusi on. Results: Preoperative knowledge of the type of operation (primary, revision), the preoperative red cell reserve, and the body mass could predict roughly half of the need for banked blood (r(2)=0.45). Only o ne-third of the total bleeding of red cells was retransfused. For comp lete avoidance of allogeneic blood, autotransfusion was most effective in patients with a moderate need (0-4 u). However, 32% of such patien ts required allogeneic blood. Conclusions: Autotransfusion has a limit ed efficacy to decrease the need for allogeneic blood, and other blood -saving methods should be added for this purpose. It is difficult to p redict the need for allogeneic blood preoperatively.