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Abstract: FR-PO432

Plasma Refill and Changes in Cognition During Hemodialysis

Session Information

Category: Dialysis

  • 801 Dialysis: Hemodialysis and Frequent Dialysis


  • Hull, Charlie, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, United States
  • Wang, (Christina) Hao, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, United States

Rapid ultrafiltration during hemodialysis has been associated with impaired cerebral perfusion. The effects of dialysis-associated hypoperfusion may be enhanced during acute illness due to factors that impair the ability to refill the vascular space (i.e., plasma refill). We sought to investigate whether changes in plasma refill are associated with detectable changes in cognitive function in hospitalized patients receiving intermittent hemodialysis.


We conducted a prospective pilot study of hospitalized patients receiving intermittent hemodialysis at the University of Pennsylvania. Blood pressure was monitored every 15min throughout hemodialysis. Hematocrit monitoring (using CritLine-IV) and ultrafiltration volumes were used to calculate interval plasma refill rates. Digitized cognitive tests were administered at regular intervals during each session; specifically, the Psychomotor Vigilance Test was used to measure reaction time (delayed reaction defined as the bottom 25% or >50ms slower performance) and the Trail Making Tests A/B were used to measure executive function (impaired function defined as the bottom 25% or >10s difference in completion time). Mixed effects logistic regression was used to examine the relationship between interval change in cognitive function and plasma refill rate.


In interim analysis, among 92 participants enrolled, 60 participants were able to complete at least two sets of cognitive testing. The mean age was 56.9±14.9 yr, 50.5% were female, 53% were Black and 40% were White, and 67% were receiving maintenance hemodialysis versus 33% for acute kidney injury. In the first half of hemodialysis, low plasma refill rate, defined as a plasma refill-to-ultrafiltration ratio < 0.75 was associated with delayed reaction time (OR 4.56, 95% CI 1.11-18.90, p = 0.035) and slower executive function but the latter did not reach statistical significance (OR 2.53, 95% CI 0.0.51-12.47, p = 0.253). These associations were independent of age, sex, acute versus chronic hemodialysis, and blood pressure.


These preliminary results offer insight into how changes in plasma refill might relate to tissue perfusion leading to detectable changes in cognition, particularly areas affected by the frontotemporal regions of the brain that are particularly susceptible to ischemic injury. Further evaluation in a larger cohort is needed to better evaluate the potential link.


  • NIDDK Support