title: Low dialysate potassium and central arterial pressure waveform.
abstract: BACKGROUND
  Cardiovascular mortality is high in hemodialysis (HD) patients. Early arterial pressure wave reflections predict mortality in HD patients, and HD acutely improves the central pressure waveform. Potassium (K) plays a crucial role in cardiac electrophysiology, and patients with end-stage kidney disease depend on HD for neutral K balance. We aimed to study the impact of dialysate K concentrations on central arterial pressure waveform.
  
  
  METHODS
  Thirty-three chronic HD patients were studied before and after a HD session, and the prescribed dialysate K concentration was recorded. In a subset of 23 patients without arrhythmias, pulse wave analysis was performed on radial arteries. Nine patients had dialysate K set to 1 mmol/L (group 1), and 14 patients had K set to 2 or 3 mmol/L (group 2). Augmentation index (AIx), defined as difference between the second and first systolic peak divided by central pulse pressure, was used as a measure of arterial stiffness.
  
  
  RESULTS
  HD reduced the AIx in group 1 only (p = 0.0005). Likewise, central systolic pressure was reduced in group 1 only (p = 0.006). The relative reduction of AIx post-HD was significantly higher in group 1 compared with group 2 (p < 0.0001). The association between low dialysate K and AIx reduction remained statistically significant after adjustment for variables including the change in central and peripheral systolic pressure and mean arterial pressure.
  
  
  CONCLUSIONS
  Low dialysate K is strongly and independently associated with the acute improvement of AIx.
authors.affiliation: Department of Medical Sciences, Uppsala University , Uppsala , Sweden.
authors.forename: Inga
authors.initials: I
authors.lastname: Soveri
authors.forename: Jaak
authors.initials: J
authors.lastname: Kals
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D062186:Arterial Pressure / Q000187:drug effects* / Q000502:physiology; D001795:Blood Pressure Determination; D005260:Female; D015312:Hemodialysis Solutions / Q000737:chemistry / Q000494:pharmacology* / Q000627:therapeutic use; D006801:Humans; D007676:Kidney Failure, Chronic / Q000503:physiopathology / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D011188:Potassium / Q000494:pharmacology* / Q000627:therapeutic use; D006435:Renal Dialysis; D016896:Treatment Outcome
chemical_list: D015312:Hemodialysis Solutions; D011188:Potassium
keywords: central pressure augmentation; hemodialysis; potassium