How we reduce allogenic blood transfusions in the patients undergoing surgery of ascending aorta

Background

Allogenic blood transfusion is associated with many risks. For the reduction of its usage acute normovolemic haemodilution (ANH) and intraoperative blood salvage were recommended.

Aim

The reduction of allogenic blood transfusion during the operations on ascending aorta by the usage of ANH, intraoperative salvage of blood and antifibrinolitic drug - aprotinin.

Materials and methods

During the observation period (Jan 1997-Oct 1999) there were 83 patients (13 female and 70 male) of age 56.2 ± 9.8 who underwent ascending aorta surgery. Exclusion criteria for ANH were haemoglobin concentration < 11 g/dl and haemodynamic instability. All patients were premedicated with midazolam 5 mg and meperidine 50 mg i.m. Anaesthesia: midazolam 0.1 mg/kg, fentanyl 5 µg/kg, and pancuronium 0.1 mg/kg; maintenance: the same drugs plus isoflurane 0.5-1 vol%. ANH was started after induction of anaesthesia and completed before the beginning of operation. Autologous blood 15 ml/kg was withdrawn from a. radialis into standard autologous blood collection sets containing CPDA-1. Gelatin and Hartman's solutions were infused to maintain baseline central venous pressure (CVP). 10⁶ iu of aprotinin were given i.v. and 2 × 10⁶ iu were added into the solution for extra-corporal circulation. Autologous blood was processed into packed red blood cells (PRBC), plasma and platelet. Arterial pressure, heart rate and CVP were continuously measured. Cell saver was installed in all patients. Arterial blood samples were obtained for analysis of blood gases, haemoglobin concentration, platelet count, electrolytes, acid-base status and activated coagulation time. PRBC were given toward the end of operation and in postoperative period when haemoglobin concentration was < 8.0 g/dl.

Statisticalanalysis

All data are expressed as mean values (SD).

Results

ANH procedure lasted for 20 ± 5 min and 1350 ± 150 ml of autologous blood was withdrawn. Three units of PRBC of allogenic blood were given to 59 (71.1%) out of 83 patients during their stay in hospital, while no allogenic blood had to be given to the rest of them (24 patients or 28.9%).

Discussion

The efficacy of ANH in the reduction of allogenic blood transfusion is still a debated issue [1]. Our data confirm that ANH has a beneficial effect on the reduction of allogenic blood transfusion.

Conclusion

ANH is the useful method for saving allogenic blood in major surgery.