Effects of acute normovolaemic haemodilution and partial exchange transfusion on blood product utilization, haemostasis and haemodynamics in surgery of the thoracoabdominal aorta. A cohort study in consecutive patients

Background This paper ontlines the technique of acute normovolaemic haemodi lution with partial exchange transfusion (ANHPET) in surgery of the thoraci c and thoracoabdominal aorta. Perioperative coagulation parameters and patt erns of blood product utilization observed with this technique are describe d and compared with results for historical controls treated without ANHPET. Methods. During thoracoabdominal aneurysm repair, acute normovolaemic haemo dilution with partial exchange transfusion (ANHPET) was used to withdraw of up to 3 L of blood. This was returned to the patient at the end of the rec onstruction. Albumin 5 % and stored packed red tells (PRC) were used for re placement. Seven patients underwent surgery with ANHPET, and fifteen withou t. Univariate and multivariate analysis of variance was used to examine dif ferences between these groups. Results. No differences were observed between the two groups for estimated blood loss, PRC transfused, and postoperative haemoglobin concentration. Th e ANHPET group received fewer platelets (8 rs 22 units, p=0.0004), cryoprec ipitate (0 vs 13 units, p=0.02), and desmopressin or epsilon-aninnocaproic acid (0 of 7 vs 4 of 15 patients, p=0.04). FFP use was not significantly di fferent (11 ts 17 units), Postoperatively, PTT values were less prolonged ( 26 vs 34 sec, p=0.05) and platelet concentration higher (218 vs 169x109/L, p=0.01) in the ANHPET group, A significant reduction in the total of blood products transfused was observed in the ANHPET group (30 vs 68 units, p=0.0 03), Control of hypertension was facilitated by phlebotomy so that nitrogly cerine was necessary in low doses only (0.25 - 1.0 mug/kg/min), Conclusions. ANHPET reduced blood product transfusion, improved postoperati ve haemostatic parameters and simplified the management of cross-clamping h ypertension.