[Changes in circulating blood volume in patients with ischemic heart disease during and after surgery with...

Twelve men scheduled for elective coronary bypass graft surgery were investigated. Blood volume was measured using as a tracer iodine contained in Uropolin and endogenous iron. Concentration of this markers was measured by proton induced x-ray emission PIXE) method. Arterial blood was sampled before operation, every ten minutes during extracorporeal circulation and every hour during the day of operation. Simultaneously all of the outcome and income fluids were noted so it was possible to calculate changes in blood volume related to water moving from intravascular into extravascular space or inversely. It was found that patients suffered from coronary disease had lower circulating blood volume than the normal population. During extracorporeal circulation and the first hours after operation changes in blood volume ranges +/- 20% and this was caused by continuous water exchange between intravascular and extravascular spaces. The degree and direction of the changes were not related to time and type of infused fluids used in the pump prime as well. Most of the patients had the blood volume higher after operation than before, but that did not influence blood pressure and central venous pressure significantly.