title: A model to predict optimal dialysate flow.
abstract: Diffusive clearance depends on blood (Qb) and dialysate flow (Qd) rates and the overall mass transfer area coefficient (KoA) of the dialyzer. In this article we describe a model to predict an appropriated AutoFlow (AF) factor (AF factor = Ratio Qd/Qb), that is able to provide adequate Kt/V for hemodialysis patients (HDP), while consuming lower amounts of dialysate, water and energy during the treatment. We studied in vivo the effects of three various Qd on the delivered dose of dialysis in 33 stable HDP. Hemodialysis was performed at Qd of 700 mL/mn, 500 mL/mn, and with AF, whereas specific dialysis prescriptions (treatment time, blood flow rate [Qb], and type and size of dialyzer) were kept constant. The results showed that increasing the dialysate flow rate more than the model of AF predicted had a small effect on the delivered dose of dialysis. The Kt/V (mean ± SD) was 1.52 ± 0.16 at Qd 700, 1.50 ± 0.16 at Qd 500, and 1.49 ± 0.15 with AF. The use of the AF function leads to a significant saving of dialysate fluid. The model predicts the appropriate AF factor that automatically adjusts the dialysate flow rate according to the effective blood flow rate of the patient to achieve an appreciable increase in dialysis dose at the lowest additional cost.
authors.affiliation: Service of Nephrology, Hemodialysis and Kidney Transplantation, Military Hospital of Instruction, Mohammed V, Rabat, Morocco. a_alayoud@yahoo.fr
authors.forename: Ahmed
authors.initials: A
authors.lastname: Alayoud
authors.forename: Mohammed
authors.initials: M
authors.lastname: Benyahia
authors.forename: Dina
authors.initials: D
authors.lastname: Montassir
authors.forename: Amine
authors.initials: A
authors.lastname: Hamzi
authors.forename: Yassir
authors.initials: Y
authors.lastname: Zajjari
authors.forename: Abdelali
authors.initials: A
authors.lastname: Bahadi
authors.forename: Driss
authors.initials: D
authors.lastname: El Kabbaj
authors.forename: Omar
authors.initials: O
authors.lastname: Maoujoud
authors.forename: Taoufik
authors.initials: T
authors.lastname: Aatif
authors.forename: Kawtar
authors.initials: K
authors.lastname: Hassani
authors.forename: Zouhir
authors.initials: Z
authors.lastname: Oualim
mesh_terms: D000328:Adult; D000368:Aged; D001783:Blood Flow Velocity; D018592:Cross-Over Studies; D015314:Dialysis Solutions / Q000008:administration & dosage / Q000493:pharmacokinetics*; D005260:Female; D006801:Humans; D007676:Kidney Failure, Chronic / Q000503:physiopathology / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D008962:Models, Theoretical; D011446:Prospective Studies; D006435:Renal Dialysis / Q000379:methods*
chemical_list: D015314:Dialysis Solutions