title: Sodium profiling, but not cool dialysate, increases the absolute plasma refill rate during hemodialysis.
abstract: Intradialytic hypotension is often caused by a discrepancy between ultrafiltration and plasma refilling. Increasing the plasma refill rate could therefore reduce intradialytic hypotension. We used a recently developed method to measure the effect of cool dialysate and sodium (Na) profiling on refill during hemodialysis (HD). Using a Gambro AK200 with blood volume (BV) sensor plus computer-guided external pump, a high ultrafiltration rate quickly induced a preset BV reduction. A software feedback mechanism subsequently adjusted the ultrafiltration rate continuously to maintain BV between very narrow preset boundaries. The continuously changing, software-generated ultrafiltration rate then quantitatively equalled refill. Absolute plasma refill rate was measured in six stable patients without intradialytic hypotension, undergoing HD without intervention, with cool dialysate (1 degrees C below core temperature), and with Na profiling (gradually declining from 150 to 140 mmol/l). Baseline refill rate was 20.1 + or - 4.0 ml/min (mean + or - SD). Although cool dialysate did not affect refill (22.2 + or - 4.1 ml/min, p = 0.27 vs. baseline), Na profiling induced a significant improvement (26.8 + or - 3.7 ml/min, p = 0.006 vs. baseline). Using our method to measure absolute plasma refill rate during HD, we demonstrated that Na profiling indeed improves the plasma refill rate. A potential effect of cool dialysate could not be established.
authors.affiliation: Department of Nephrology, University Medical Center Utrecht, Room F03.2.23, PO Box 85500, 3508 GA Utrecht, The Netherlands. w.j.brummelhuis@gmail.com
authors.forename: Walter J
authors.initials: WJ
authors.lastname: Brummelhuis
authors.forename: Rob J
authors.initials: RJ
authors.lastname: van Geest
authors.forename: Leonard J
authors.initials: LJ
authors.lastname: van Schelven
authors.forename: Walther H
authors.initials: WH
authors.lastname: Boer
mesh_terms: D015314:Dialysis Solutions / Q000737:chemistry*; D006801:Humans; D007022:Hypotension / Q000209:etiology / Q000517:prevention & control*; D006435:Renal Dialysis / Q000009:adverse effects* / Q000379:methods*; D012964:Sodium / Q000032:analysis*
chemical_list: D015314:Dialysis Solutions; D012964:Sodium