ACUTE HEMODYNAMIC-EFFECTS OF PREOPERATIVE HEMODILUTION WITH BOVINE HEMOGLOBIN FOR LIVER SURGERY

Haemoglobin solutions can be an alternative to allogeneic red-cell tra nsfusions because they combine colloid osmotic with oxygen transport p roperties. Since severe toxic side effects have been overcome by ultra purification, clinical interest has been focused on haemodynamics chan ges during application of haemoglobin preparations. The present clinic al study examines changes of haemodynamic and oxygen transport paramet ers during and after haemodilution with ultrapurified polymerized bovi ne haemoglobin (HBOC-201) in comparison to hydroxyethyl starch (HES). Methods: After approval of the Ethics Committee, 12 patients (6 males and 6 females, mean age 59 +/- 10 years, ASA 1-2) undergoing elective liver resection were randomly allocated to receive either 3 ml.kg(-1) 6% HES 70000/0.5 (group 1) or 0.49.kg(-1) HBOC-201 (group 2) within 30 min following autologous blood donation of 1 I and substitution with 2 I Ringer's lactate. Measurements of blood gases, haemodynamics, and oxygen transport parameters were performed after induction of general anaesthesia, prior to and after blood donation, during and after infus ion,at the beginning of surgery, and in the intensive care unit.Result s: Demographic characteristics did not differ between groups. In contr ast to the HES group, mean arterial pressure increased by 18% over bas eline measurements in group 2. While pulmonary vascular resistance sho wed a trend to higher values in group 2, systemic vascular resistance increased to a maximum of 42% over baseline in group 2 and was twice a s high as in the HES group. The cardiac index was lower in the HBOC-20 1 group than in the HES group. During and after HBOC-201 infusion, mix ed-venous oxygen saturation and content and calculated oxygen delivery were lower in group 2 in comparison to group 1, while the oxygen extr action ratio was higher in group 2. Free haemoglobin reached a maximal concentration of 1.0 +/- 0.2 g.dl(-1) 30 min after the HBOC-201 infus ion was started, but was not detectable in urine over time. The mean i ntravascular half-life of HBOC-201 was 8.5 h. Conclusions: Patients di d not show any severe complications during and after infusion of HBOC- 2O1. However, vasoconstrictive side effects resulted in increased syst emic but not pulmonary resistance. Ongoing studies with higher doses o f HBOC-201 applied in a larger number of patients will probably reveal potential clinical consequences of the demonstrated haemodynamic chan ges.