P1423INCREASED BLOOD FLOW RATE IN HIGH-FLUX HAEMODIALYSIS - IS IT RELEVANT FOR PHOSPHORUS REMOVAL IN HAEMODIALYSIS PATIENTS?

Abstract

Abstract Background and Aims High-flux haemodialysis (HD), beside other uremic solutes harmful for patients, controls the level of phosphorus, major factor for HD-related morbidity and mortality. First line in phosphorus control in HD patients is dietary phosphorus intake reduction, whereas its’ removal is undervalued by hemodialysis. The primary objective was to analyse whether change in the rate of blood flow is relevant in phosphorus removal in HD patients. Second objective was to evaluate other variables impacted by higher blood flow rates. Method Retrospective study was conducted enrolling 80 patients from a single center in a period of 12 months. In the first six months, all patients were on lower blood flow rate (LBFR group) than the same patient group was switched to a higher blood flow rate in the following six months (HBFR group). Demographic, clinical and laboratory variables were collected and intra/inter-patient group analysis was performed. Results Forty-seven patients were male, and 41.3% were female. Mean age of the study population was 61.2±13.47 years (males 60.3±13.38, females 62.4±13.68). Mean dialysis vintage was 63.31±66.57 months. The average real blood flow rate in LBFR group was 290.75±19.65 ml/min (median 285.34 ml/min), 344.87±9.12 ml/min in HBFR group (median 339 ml/min), p=0.0002. The level of phosphorus in LBFR group was 1.52±0.03 mmol/L, and 1.45±0.04 in HBFR group, p=0.007. Other variables that significantly showed improvement following the increase of blood flow rate were eKT/V (p=0.0006), urea clearance (p=0.02) and transferrin saturation (p=0.04). The level of post-HD urea (p=0.02) and body surface area (p=0.04) were decreased. Weekly EPO dosage decrease in HBFR group (p=0.02) was not correlated with increased iron sucrose administration (LBFR group 59.99±36.18 mg/wk, HBFR group 65.8±28.7, p=0.45). There were no significant changes related to cardiac function; systolic (p=0.44) and diastolic pressure (p=0.36), mean arterial (p=0.43) and pulse pressure (p=0.26) remained in reference range. Also, the average dose of calcium-based phosphate binders did not change significantly (p=0.34). Conclusion This study showed that increased blood flow rate in HD patients reduces phosphorus and EPO consumption, improves urea clearance without significant impact on cardiac function and calcium overload with calcium-based phosphate binders.