Acute normovolaemic haemodilution vs controlled hypotension for reducing the use of allogeneic blood in patients undergoing radical prostatectomy

Blood loss in patients undergoing radical prostatectomy may be substantial. In a randomized, prospective study, we assessed two methods of reducing the need for allogeneic blood transfusion with regard to efficacy and costs. Sixty patients undergoing retropubic radical prostatectomy were allocated randomly to one of three groups. In group 1 (n = 20), acute normovolaemic haemodilution (ANH) was initiated after induction of anaesthesia; autologous blood 15 ml kg-1 was withdrawn and replaced by colloid solutions (gelatin) to maintain haemodynamic stability. In group 2 (n = 20), controlled hypotension was established using sodium nitroprusside (target mean arterial pressure (MAP) approximately 50 mm Hg). Group 3 (n = 20), without manipulations, served as a control group. Troponin T (TnT), a sensitive marker for myocardial ischaemia, and various coagulation variables were measured in the perioperative period. Packed red blood cells (PRBC) were given when haemoglobin concentration was less than 7 g dl-1. Cost calculations did not include hospital overhead costs or staff costs. In the ANH group, mean 1278 (SD 150) ml of autologous blood were withdrawn. Significantly more volume was infused in the ANH patients (gelatin 2450 (550) ml) than in the two other groups. Coagulation data (platelet count, activated partial thromboplastin time (aPTT), fibrinogen, antithrombin III (AT III), D-dimers) did not differ significantly between the three groups. The hypotension group had significantly lower blood loss (1260 (570) ml), whereas the ANH (1820 (680) ml) and control group (1920 (590) ml) did not differ significantly. Patients in the hypotension group needed significantly less PRBC (total 14 units; 75% of patients did not need PRBC) than the ANH (total 21 units; 55% of patients did not need PRBC) or control patients (total 28 units; 40% of patients did not need PRBC). Total costs were lowest in the hypotension group (41% less than in the control patients) (P < 0.05). We conclude that the use of hypotension during radical prostatectomy resulted in approximately 40% reduction in total transfusion costs. ANH was less effective and more costly than controlled hypotension.