Effects of peritoneal dialysis on erythrocyte deformability in chronic renal failure

Abstract

Previous studies on this subject showed different results contrarily. Aim: The aim of the study was to evaluate selected rheological parameters in patients with renal insufficiency undergoing continuous ambulatory peritoneal dialysis. Methods: Venous blood samples were obtained from 35 volunteers (20 patients/15 controls). Blood viscosity was measured at both native hematocrit (Hct) and corrected as 45% using a cone-plate viscometer. Deformability Indexes (Elongation index (EI), maximum elongation index (EImax) and Half-maximal shear stress (SS1/2)) were measured with an ektacytometer (LORRCA). T-test and Mann-Whitney U were used for statistics. Results: Average Hct of the patients (33%±6) was significantly less than the control group (44%±3). While plasma viscosity in the patients was significantly increased, whole blood viscosity of native Hct was significantly decreased at all shear rates resulting from low Hct. Blood viscosity of corrected Hct was increased at each shear rate in the patients compared to the control, although the differences were statistically significant only for the shear rates of 150 s-1and 300 s-1. The EI was found significantly decreased only at two among ten different shear stresses. EImax was significantly higher in the patients than the control and SS1/2 was significantly increased (p<0.05). Conclusions: These results imply that uremic conditions, loss of plasma proteins and increment of oxidative risk, which are previously reported for the peritoneal dialysis patients in the literature, may raise erythrocyte rigidity. Deteriorated mechanical properties of erythrocytes with peritoneal dialysis may have crucial effects on impaired blood flow dynamics and cause inadequate microcirculatory perfusion.