The use of acute normovolemic hemodilution in patients undergoing cardiac surgery

Avoiding allogeneic blood transfusion during cardiac surgery and during the post-operative period is of great importance. Acute normovolemic hemodilution (ANH) is one of the options for blood salvage. We have prospectively analyzed 310 consecutive patients (pts) after different open heart procedures, operated on during April-May, 2000. ANH was possible in 226 pts (73%) with hemoglobin level over 125 g/l and hematocrit over 36%. Of those, one unit of blood was withdrawn in 128 pts (70%), while two to five units of blood were taken in 68 pts (30%). Total number of autologous blood units taken was 296, for the average of 1.31 units/pt. Predictors of increased intra- and post-operative blood loss were hematocrit (Hct) <39% (76% vs. 24%, p<0.001), age over 65 (p=0.028), female sex (p=0.006), CPB duration over 90 min (63% vs. 37%; p<0.001) and preoperative left ventricular ejection fraction (LVEF) <35% (63% vs. 37%; p<0.001). All pts with the above-mentioned characteristics were in need for allogeneic blood transfusion. During their hospital stay, 142 pts did not get allogeneic blood (142/310, 46%), and all were in the ANH group (142/226, 62%).