The effect of multiple blood conservation techniques on donor blood exposures in adult coronary and valve surgery performed with a membrane oxygenator: A multivariate analysis on 1310 patients

The object of the study was to retrospectively evaluate protective and risk factors for receiving donor blood products and red cell transfusions after coronary and valve surgery performed with a hollow-fiber oxygenator and with multiple blood-saving techniques. During the period of January 1991 to June 1993, 1310 patients underwent primary coronary and valve surgery using a hollow-fiber oxygenator at our institution; the mean age of this population was 61 ± 10 years; 977 patients were men (74.6%). Of these patients, 73.5% (963/1310) underwent coronary, 21.5% (281/1310) valve, and 5% (66/1310) combined surgery. Two hundred seventy-six (21.1%) needed donor blood product transfusions, while 153 (11.7%) patients underwent red cell transfusions. Significant risk factors for homologous blood product exposure after multivariate logistic regression analysis were, in order of importance: (1) postoperative blood loss (O.R. = 1.0009 per mL, p = 0.0000); (2) cardiopulmonary bypass (CPB) time (O.R. = 1.008 per min, p = 0.0001); (3) age at intervention (O.R. = 1.031 per calendar year, p = 0.0026); and (4) reoperation for bleeding (O.R. = 1.71, p = 0.0078). Protective factors were: (1) male gender (O.R. = 0.56, p = 0.0000); (2) preoperative withdrawal of autologous blood (O.R. = 0.66, p = 0.0016); and (3) a preoperative hematocrit greater than 34% (O.R. = 0.76, p = 0.005). When considering risk factors only for donor red cell exposure, multivariate regression analysis identified the following risk factors: (1) reoperations for bleeding (O.R. = 2.04, p = 0.0002); (2) postoperative blood losses (O.R. = 1.0007 per mL, p = 0.0005); (3) CPB time (O.R. = 1.0075 per min, p = 0.0008); and (4) age at intervention (O.R. = 1.03 per calendar year, p = 0.0160). Protective factors were: (1) intraoperative 'high-dose' aprotinin administration (O.R. = 0.61, p = 0.0024); and (2) preoperative donation if autologous blood (O.R. = 0.65, p = 0.0093); and (3) intraoperative withdrawal of autologous blood by phlebotomy (O.R. = 0.67, p = 0.0114). Applying multiple blood-saving techniques, coronary and valve procedures can now be performed with a low incidence of postoperative donor blood products and red cells exposures; autologous blood predonation and aprotinin administration were highly effective in reducing postoperative transfusion needs.