P1524absolute Blood Volume and Vascular Refilling in Haemodialysis Patients

Abstract

Background and Aims The imbalance between UF and refilling rate is considered a major cause for intradialytic hypotension. Recent studies report a feasable and noninvasive method to estimate vascular refilling by determining absolute blood volume. It was the aim of this study to analyze absolute blood volume in a group of haemodialysis patients and to examine vascular refilling volume. Method Thirty stable chronic HD patients were studied (36,7% female, 63,3% male), aged 71,07 ± 13,31 years. Dialysis duration and UF requirements were based on physician prescription. Vascular refilling was calculated as: VREF = VUF – ΔV, where ΔV is the difference between absolute blood volume at the beginning and the end of dialysis. Relative blood volume monitor (BVM) was used. Hemodial Int. 2016;20(3):484–91. Results Absolute blood volume at the beginning of the dialysis was 6,27 ± 2,78 L (92,44 ± 32,66 ml/kg) and at the end 5,83 ± 2,77 L (85,94 ± 30,44 ml/kg). Ultrafiltration (UF) volume was 2,64 ± 0,82 L (11,14 ± 4,02 ml/kg/h). Vascular refilling was calculated as 2,24 ± 0,74 L, with a refilling fraction of 85,33 ± 11,07%. We found a strong correlation between refilling volume and UF volume (r2 0,861) (Figure 1), and a mild correlation between refilling volume and predialysis volume overload (r2 0,529). Conclusion Measurement of absolute blood volume is easy and noninvasive, and it allows us to study refilling volume. We found a strong correlation between UF volume and refilling volume.

An improved method to estimate absolute blood volume based on dialysate dilution

“…6 As information on absolute BV is most convenient when available directly at treatment start so that the proper ultrafiltration (UF) target can be set at the beginning of dialysis, the technique was established for measurement immediately after the beginning of dialysis. 1,6,7 Adoption of this method by different groups [8][9][10][11] revealed some methodological issues incompletely appreciated before. The purpose of this study was to revisit the original method description, provide more detail on treatment conditions and timing of measurements, and to analyze how timing will affect the reproducibility of measurements.…”

“…Adoption of this method by different groups 8‐11 revealed some methodological issues incompletely appreciated before. The purpose of this study was to revisit the original method description, provide more detail on treatment conditions and timing of measurements, and to analyze how timing will affect the reproducibility of measurements.…”