Abstract
Purpose: For the first step to investigate the blood volume change during hemodialysis, we studied it without ultrafiltration. Methods: Ten chronic hemodialysis patients were studied. We measured the hematocrit during hemodialysis and calculated the blood volume (BV) change continuously using CRITLINE (IN-LINE DIAGNOSTICS). We approximated the time-sequential changes in BV (ΔBV) to the equation: ΔBV(%)=a×{1-exp[-b×TIME (hr)]}-c×TIME (hr) and determined the relationship between the coefficients (a, b, c) and clinical parameters. Results: 1) In all patients, BV was increased during hemodialysis and could be approximated to the equation very well (0.92<r<0.99, p<0.0001). 2) Coefficient (a), the degree of increase of BV, was 8.66±2.92 and almost equal to the percentage of the lost BV for the extracorporeal circuit to the whole By. Coefficient (a) was significantly related to the cardio-thoratic ratio of the chest X-ray film (CTR) (r=0.88, p=0.0008) and serum albumin concentration before hemodialysis (r=0.80, p=0.03). 3) Coefficient (b), the speed of increase of BV, was 2.02±0.77, 99.9% of the total increase was achieved by 2 hours after the beginning of hemodialysis. 4) Coefficient (c) varied from -1.64 to 1.06, and was related to no clinical parameters. Conclusions: BV was increased during hemodialysis without ultrafiltration. The mechanism of the BV increase was thought to cover the lost BV for the extracorporeal circuit. Coefficient (a) could be the indices of hydration and plasma refilling.
