Hemodynamics During Dialysis and Changes in Cognitive Performance.

INTRODUCTION: Hemodialysis (HD) patients are at increased risk for cognitive impairment. Blood pressure (BP) fluctuations during HD may affect cerebral perfusion and subsequently cognitive function.

OBJECTIVE: Examine and provide information on the relationship between intradialytic hemodynamics and cognitive outcomes over a 1-year period.

METHODS: HD patients without diagnosed dementia who were 50 years old or older were given a neurocognitive battery at baseline and at 1-year follow-up. Over the 1-year period, we collected demographic and laboratory data, as well as dialytic BP and ultrafiltration rate (UFR) measurements and tested the association between changes in cognitive test scores and intradialytic hemodynamics, adjusting for demographic and clinical variables.

RESULTS: Thirty-nine participants enrolled in the study and 32 remained at 1-year follow-up. The mean (SD) age was 66.8 (10.0) years. Hypertension was present in 100% and diabetes mellitus in 47% of the cohort. The average change in systolic BP from predialysis to postdialysis was -9.9 (16.3) mmHg, and average maximum drop in systolic BP during dialysis was 27.9 (10.2) mmHg. Overall, the cognitive test scores did not have significant changes from baseline to 1 year. In our linear regression analysis there was no association between the BP measures and cognitive changes, although UFR was associated with change in performance on a test of executive functioning.

CONCLUSIONS: In prevalent HD patients, cognitive function was generally stable over a 1-year period, and there was no association with intradialytic hemodynamic variables.