Online Kt/V monitoring in haemodialysis by UV absorbance: variations during intra-dialytic meals.

BACKGROUND/AIMS: The aim of this study was to analyse if intra-dialytic food intake may lead to changes in online Kt/V.

METHODS

Forty patients were analysed using haemodialysis machines with integrated online Kt/V monitoring based on UV absorbance or ionic dialysance. Kt/V was monitored before, during and after food intake. Samples of dialysate were analysed for urea, uric acid, creatinine and glucose levels.

RESULTS

Food intake was associated with a significant decrease in relative Kt/V when determined by UV absorbance. The drop in Kt/V was independent of changes in blood pressure or body posture. No significant changes in online Kt/V were found using the ionic dialysance method. Dialysate samples showed a continuous clearance of urea, uric acid and creatinine during meals but a rapid increase in glucose.

CONCLUSION

Our data suggest that the short meal-associated decrease in online Kt/V as measured by UV absorbance does not represent a true decline in Kt/V but might reflect an intermittent increase in UV-absorbing dialysed solutes.