DILUTING EFFECT OF COLLOIDS IN LOW SHEAR RATE CONDITIONS WPŁYW ROZCIEŃCZENIA KRWI PŁYNAMI KOLOIDOWYMI NA LEPKOŚĆ KRWI W ZAKRESIE NISKICH PRĘDKOŚCI ŚCINANIA

Summary Introduction. Hemodilution is one of the methods used in the treatment of peripheral circulatory disturbances. There is a lot of discus- sion about the influence of hemodilution and different kinds of fluids on the metabolism of the organism. Aim of the study. We investigated the influence of kind of colloid fluids used for transfusion on the rheological parameters of blood. Material and Methods. The blood viscosity measurements were performed with the use of a rotary-oscillatory rheometer Contraves LS 40. The investigation included measurements of blood viscosity and a haematocrit value at three stages: before, just after and two hours after transfusion. A group of 40 patients in the age between 45 and 75 years (60 years on average) was chosen for the investigation of the rheological parameters of blood in patients prepared for procedures in epidural anaesthesia. The choice was restricted to patients pre- pared for operations of scrotal or inguinal hernia. Patients suffering from vascular system diseases requiring long-term pharmacological treatment were automatically excluded from the group. In the first subgroup we used Dextran 40 (Polfa Kutno, Poland) with the recom- mended amount of 7 ml per kg body mass (up to the volume of 500 ml) and in the second subgroup 10% HES 200/05 (Fresenius AG, Germany) with the recommended amount of 4 ml per kg body mass (up to the volume of 500 ml). Results and Conclusion. Measurements of blood viscosity at the shear rate of 1 s-1 showed that this viscosity had the lowest value in the group of patients with HES 200/0.5 as a transfusion fluid (p < 0.001).