Guidance for clinical use of a haemoconcentration-based determination of recirculation in dialysis: Reproducibility, reliability, sensitivity of the measurements in clinical practice

BACKGROUND: Blood access is of outmost importance for haemodialysis treated patients. Access blood flow is the first determining factor conditioning blood volume, clearance and dialysis delivery. Access blood flow reduction may result in increased recirculation of the extracorporeal circuit and dialysis deficiency, and be indicative of a pre-thrombosis state. Modern dialysis monitors are equipped with automatic systems to determine recirculation. AIM: We aimed at assessing the reproducibility, reliability and sensitivity of recirculation ratio measurements during its use in clinics. METHODS: Forty-four unselected patients routinely treated with a monitor equipped with an ultrafiltration-based density modification to automatic assessment of recirculation were included in the study and two hundred and sixty-four dialysis procedures with over one thousand measurements of recirculation were analysed. RESULTS: The median recirculation ratio observed was 3% and interquartile range of 6. Only 4% of the measurements were between 10% and 15% and 6% were greater than 15%. The observed recirculation ratio values were consistent throughout the dialysis sessions and reproducible as 90% of sessions had a difference in maximum values up to 10%. CONCLUSIONS: Recirculation monitoring remains an important parameter to prevent both blood access complications and dialysis insufficiency. Recirculation measurements showed to be uneventful and provided relevant clinical information.