Identifying Therapeutic Hemodialysis Targets Through Cerebrovascular Reactivity; RESPIRACT 2

Patients with chronic kidney disease receiving hemodialysis (HD) suffer from higher rates of brain vascular disease and decreased cognition than the general population. One way to assess brain vascular health and response to HD stress, is to test how the brain's blood flow responds to carbon dioxide (CO2) to measure Cerebrovascular Reactivity (CVR). In this study, the investigators will compare the magnitude and speed of the brain's blood flow response to a step-wise change in CO2 with hemodynamic, dialysis, and cognitive parameters. The goal of the study is to establish therapeutic targets that can be altered during the dialysis procedure to protect the brain from HD stress.