title: A model of systolic blood pressure during the course of dialysis and clinical factors associated with various blood pressure behaviors.
abstract: BACKGROUND
  Little is known about the behavior of systolic blood pressure (SBP) during hemodialysis.
  
  
  METHODS
  Prospective observational cohort.
  
  
  METHODS
  218 prevalent hemodialysis patients treated at 5 participating DaVita Dialysis units.
  
  
  METHODS
  Clinical variables that may plausibly influence the behavior of SBP during the course of hemodialysis sessions.
  
  
  RESULTS
  SBP at the onset of dialysis and its rate of change (slope) over the first 25% and latter 75% of the treatment interval.
  
  
  METHODS
  SBPs measured and recorded per clinical protocol during the first 30 days of study (median, 11 treatments/patient; SBP measured at 30-minute intervals).
  
  
  RESULTS
  Intradialytic SBP behavior is well characterized by a 2-slope linear spline model, which describes SBP at time zero, a rapid decrease during the first 25% of the treatment (early), and a more gradual decrease thereafter (late). Higher ultrafiltration volume and rate each are associated with greater SBP at the start of dialysis and more rapid early and late SBP decreases. Use of a higher number of antihypertensives was associated with greater time zero SBP. Calcium acetate use is associated with high SBP at the start of hemodialysis and a more pronounced decrease during the early and late parts of treatment.
  
  
  CONCLUSIONS
  Over-representation of blacks and patients with congestive heart failure; observational design; use of clinically measured blood pressures.
  
  
  CONCLUSIONS
  Intradialytic SBP can be characterized using 3 parameters: value at the start of dialysis and slopes during the first 25% and latter 75% of treatment. Practices related to fluid management, antihypertensive use, and metabolic bone disease control are associated with blood pressure behavior during dialysis. Further work is needed to confirm findings and measure associations between various aspects of intradialytic blood pressure behavior and clinical outcomes.
authors.affiliation: Division of Nephrology, Department of Medicine, University of California, Davis School of Medicine, Sacramento, CA, USA.
authors.forename: Kumar
authors.initials: K
authors.lastname: Dinesh
authors.forename: Srikanth
authors.initials: S
authors.lastname: Kunaparaju
authors.forename: Kathryn
authors.initials: K
authors.lastname: Cape
authors.forename: Jennifer E
authors.initials: JE
authors.lastname: Flythe
authors.forename: Harold I
authors.initials: HI
authors.lastname: Feldman
authors.forename: Steven M
authors.initials: SM
authors.lastname: Brunelli
mesh_terms: D001794:Blood Pressure; D005260:Female; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008875:Middle Aged; D008955:Models, Cardiovascular; D011446:Prospective Studies; D006435:Renal Dialysis