title: Physiologic variability of vascular access blood flow for hemodialysis.
abstract: OBJECTIVE
  To assess the variability of blood flow (QVA) through a native arteriovenous fistula (AVF) in the long-term and to determine the QVA reduction at which an intervention is appropriate.
  
  
  METHODS
  The study was performed in a group of 34 chronic hemodialysis patients with no history of a AVF intervention. QVA was measured using the thermodilution method (Blood Thermodilution Monitor, Fresenius). Median follow-up was 41 months and the median number of QVA measurements in each patient was 15. The coefficient of variation (CV) of QVA was calculated for each patient.
  
  
  RESULTS
  Mean QVA was 904 +/- 334 ml/min. The mean CV was 23.3 +/- 11.2%.
  
  
  CONCLUSIONS
  QVA may fluctuate during a long-term follow-up period. The detection of QVA decrease by 20-25% could be still within physiological limits. Based on the results we recommend to first repeat the measurement at a shorter interval and to refer the patient to a radiologist only when the decreasing trend is confirmed.
authors.affiliation: Department of Internal Medicine Strahov, General University Hospital, Prague, Czech Republic. m.valek@seznam.cz
authors.forename: Martin
authors.initials: M
authors.lastname: Válek
authors.forename: Frantisek
authors.initials: F
authors.lastname: Lopot
authors.forename: Sylvie
authors.initials: S
authors.lastname: Dusilová-Sulková
authors.forename: Vladimír
authors.initials: V
authors.lastname: Polakovic
mesh_terms: D000368:Aged; D001164:Arteriovenous Fistula / Q000503:physiopathology* / Q000628:therapy; D001783:Blood Flow Velocity; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D006435:Renal Dialysis; D012189:Retrospective Studies