title: Ionic dialysance and determination of Kt/V in on-line hemodiafiltration with simultaneous pre- and post-dilution.
abstract: OBJECTIVE
  A direct determination of Kt/V using ionic dialysance for estimating K and bio-impedancemetry for estimating V is compared with the usual indirect estimation based on the second generation Daugirdas equation during a new technique of hemodiafiltration with simultaneous pre- and post-dilution (mixed-HDF).
  
  
  METHODS
  In 31 informed consented patients, the urea distribution volume (V) is estimated by total body water (VBCM  ) measured by the Body Composition Monitor (BCM; Fresenius Medical Care, Bad Homburg, Germany) based on bio-impedance spectroscopy. The value (KOCM t)/VBCM is calculated during 114 mixed-HDF sessions (duration 4 hours) from the measurement of ionic dialysance KOCM by the OCM module, standard on the 5008 dialysis monitor (Fresenius Medical Care, Germany). The single pool (Kt/V)sp is determined from blood urea concentration measurements using the Daugirdas equation.
  
  
  RESULTS
  Mixed-HDF is a very high-efficiency hemodialysis with a delivered dialysis dose Kt/V near from 2 per 4-hour session. (KOCM t)/VBCM (1.97 ± 0.28) is consistent with (Kt/V)sp (2.01 ± 0.34) with a correlation coefficient at 0.72.
  
  
  CONCLUSIONS
  Direct calculation of Kt/V from estimating K by OCM and V by BCM is consistent with the usual indirect estimation by the second generation Daugirdas equation. Therefore, the regular determination of V by BCM allows the estimation of single-pool Kt/V at each session without the need of blood sampling.
authors.affiliation: Hemodialysis Center Henri Küntziger, AURA, Paris, France. caroline.creput@auraparis.org
authors.forename: Caroline
authors.initials: C
authors.lastname: Créput
authors.forename: Daniel
authors.initials: D
authors.lastname: Toledano
authors.forename: Thierry
authors.initials: T
authors.lastname: Petitclerc
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001823:Body Composition; D001834:Body Water / Q000378:metabolism; D058266:Dielectric Spectroscopy; D017097:Electric Impedance; D005260:Female; D015312:Hemodialysis Solutions / Q000737:chemistry / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D009994:Osmolar Concentration; D006435:Renal Dialysis / Q000379:methods*; D014508:Urea / Q000097:blood
chemical_list: D015312:Hemodialysis Solutions; D014508:Urea