Acute preoperative hemodilution in patients undergoing radical prostatectomy: a case study analysis of efficacy

Despite published guideline and consensus conference recommendations, the role of acute preoperative hemodilution in elective surgery has not been defined. We performed a case study analysis of this technique in a large surgical program in order to estimate its degree of efficacy as practiced routinely, and to better define its role as a blood conservation strategy. Patients undergoing elective radical prostatectomy by one surgeon during a 3-yr period were analyzed retrospectively for blood loss, hematocrit levels, records of acute hemodilution, and transfusion outcomes. Patient blood volumes were determined by nomogram; final hematocrits after discrete blood volumes lost by surgery or by hemodilution were estimated. Sixteen (4.4%) of 410 total patients reviewed underwent hemodilution, representing 0 (0%), 4 (3%), and 12 (8%) of the 112, 146, and 152 patients undergoing surgery in years 1, 2, and 3, respectively. Median whole blood volume and mean red blood cell (RBC) volume removed by hemodilution was 1000 mL (range, 400-1500 mL) and 338 mL (range, 156-585 mL), respectively, representing 15% of patients' admission RBC volume. Net intraoperative RBC volume "saved" in losses by this technique was 95 mL (range, 25-204 mL), representing only 9.3% (range, 4%-17%) of total RBC volume lost during hospitalization. RBC volume removed by hemodilution constituted 34% (95-283 mL) of the total RBC volume transfused. We conclude that use of acute preoperative hemodilution remains in evolution and, as a single blood conservation intervention, contributes only modestly to blood conservation.