Identifying Therapeutic Hemodialysis Targets Through Cerebrovascular Reactivity; RESPIRACT 2

NCT05445219 | Active Not Recruiting

• 1 other identifier: 121136
• Study Type: observational
• Target: 37
• Locations: 1 country
• Sites: 1

Brief Summary

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.

Conditions

Chronic Kidney Failure

Keywords

Hemodialysis; Cerebrovascular Reactivity; Cognitive Impairment

Outcome Measures

Primary Outcomes (8)

• Baseline RespirAct measurement Pre Dialysis Weekday Treatment

  The CVR diagnostic assessment with the RespirAct will be performed prior to the dialysis treatment by all consenting patients on a weekday HD session. Examining CVR before the dialysis session will allow for insight into the patient's baseline CVR function. CVR via the RespirAct device is an automated breathing circuit that uses a gas bladder to control and deliver carbon dioxide (CO2). It has various gas cylinders that are used in order to obtain the correct increase in CO2 in each patient.

  20 minutes to complete the assessment before HD treatment

• RespirAct measurement Post Dialysis Weekday Treatment

  The CVR diagnostic assessment with the RespirAct will be performed after the dialysis treatment by all consenting patients on a weekday HD session. Examining CVR after the dialysis session will allow for insight into how the patient's CVR function has been altered by the dialysis treatment. CVR via the RespirAct device is an automated breathing circuit that uses a gas bladder to control and deliver carbon dioxide (CO2). It has various gas cylinders that are used in order to obtain the correct increase in CO2 in each patient.

  20 minutes to complete the assessment after HD treatment

• Baseline RespirAct measurement Pre Dialysis Weekend Treatment

  The CVR diagnostic assessment with the RespirAct will be performed prior to the dialysis treatment by all consenting patients on a weekend HD session. Examining CVR before the dialysis session will allow for insight into the patient's baseline CVR function. By timing this assessment after the weekend dialysis break insight into how CV is affected by fluid status can be observed. CVR via the RespirAct device is an automated breathing circuit that uses a gas bladder to control and deliver carbon dioxide (CO2). It has various gas cylinders that are used in order to obtain the correct increase in CO2 in each patient.

  20 minutes to complete the assessment before HD treatment

• RespirAct measurement Post Dialysis Weekend Treatment

  The CVR diagnostic assessment with the RespirAct will be performed after the dialysis treatment by all consenting patients on a weekend HD session. Examining CVR after the dialysis session will allow for insight into how the patient's CVR function has been altered by the dialysis treatment. Specifically, HD sessions after the weekend dialysis break require higher ultrafiltration rates as more fluid is retained by the patients. This leads to a more aggressive treatment to get the patient down to their dry weight. Therefore, having this treatment follow the weekend break dialysis treatment the intensity of dialysis treatment and its effects on CVR can be assessed. CVR via the RespirAct device is an automated breathing circuit that uses a gas bladder to control and deliver carbon dioxide (CO2). It has various gas cylinders that are used in order to obtain the correct increase in CO2 in each patient.

  20 minutes to complete the assessment after HD treatment

• Baseline Doppler measurement Pre Dialysis Weekday Treatment

  The CVR diagnostic assessment also needs to include Doppler in order to obtain arterial blood flow velocity. This will be performed prior to the dialysis treatment by all consenting patients on a weekday HD session. Examining CVR before the dialysis session will allow for insight into the patient's baseline CVR function.

  20 minutes to complete the assessment before HD treatment

• Doppler measurement Post Dialysis Weekday Treatment

  The CVR diagnostic assessment also needs to include Doppler in order to obtain arterial blood flow velocity. This will be performed after the dialysis treatment by all consenting patients on a weekday HD session. Examining CVR after the dialysis session will allow for insight into whether the patient's CVR function was changed by the HD treatment.

  20 minutes to complete the assessment before HD treatment

• Baseline Doppler measurement Pre Dialysis Weekend Treatment

  The CVR diagnostic assessment also needs to include Doppler in order to obtain arterial blood flow velocity. This will be performed prior to the dialysis treatment by all consenting patients on a weekday HD session. Examining CVR before the dialysis session will allow for insight into the patient's baseline CVR function while having more fluid retained, as there has been a weekend break since the last HD session.

  20 minutes to complete the assessment before HD treatment

• Doppler measurement Post Dialysis Weekend Treatment

  The CVR diagnostic assessment also needs to include Doppler in order to obtain arterial blood flow velocity. This will be performed after the dialysis treatment by all consenting patients on a weekday HD session. Examining CVR after the dialysis session will allow for insight into whether the patient's CVR function was changed by the HD treatment. Having this treatment follow the weekend break dialysis treatment the intensity of dialysis treatment and its effects on CVR can be assessed.

  20 minutes to complete the assessment after HD treatment

Secondary Outcomes (26)

• Heart Rate Monitoring by Finapres NOVA- weekday treatment

  Duration of the CVR assessment and HD treatment (roughly 4.5 hours)

• Blood Pressure Monitoring by Finapres NOVA- weekday treatment

  Duration of the CVR assessment and HD treatment (roughly 4.5 hours)

• Mean Arterial Pressure Monitoring by Finapres NOVA- weekday treatment

  Duration of the CVR assessment and HD treatment (roughly 4.5 hours)

• Heart Rate Monitoring by Finapres NOVA- weekend treatment

  Duration of the CVR assessment and HD treatment (roughly 4.5 hours)

• Blood Pressure Monitoring by Finapres NOVA- weekend treatment

  Duration of the CVR assessment and HD treatment (roughly 4.5 hours)

Interventions

RespirAct DIAGNOSTIC_TEST

The RespirAct device is an automated breathing circuit that uses a gas bladder to control and deliver CO2 to measure cerebrovascular reactivity

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

Patients ≥ 18 years old, receiving hemodialysis treatment at least 3 times per week at a London Health Sciences Centre facility

You may qualify if:

• Patients ≥ 18 years old, receiving hemodialysis treatment at least 3 times per week at a London Health Sciences Centre facility
• English proficiency

You may not qualify if:

• Mental incapacity to consent
• Declined to participate
• Severe chronic obstructive lung disease (COPD) /Asthma
• History of cerebrovascular accident (stroke, transient ischemic attack)
• Previous neurosurgery
• History of carotid stenosis or carotid surgery
• History of vasculitis
• Documented Dementia
• Pregnancy
• Not fluent in English

Sponsors & Collaborators

• London Health Sciences Centre Research Institute OR Lawson Research Institute of St. Joseph's: lead
• Heart and Stroke Foundation of Canada: collaborator

Study Sites (1)

London Health Sciences Centre

London, Ontario, N6A 5W9, Canada

Location

MeSH Terms

Conditions

Kidney Failure, Chronic; Cognitive Dysfunction

Condition Hierarchy (Ancestors)

Renal Insufficiency, Chronic; Renal Insufficiency; Kidney Diseases; Urologic Diseases; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Urogenital Diseases; Male Urogenital Diseases; Chronic Disease; Disease Attributes; Pathologic Processes; Pathological Conditions, Signs and Symptoms; Cognition Disorders; Neurocognitive Disorders; Mental Disorders

Study Officials

• Christopher W McIntyre, MD/PHD

  London Health Sciences Centre - Victoria Hospital

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: CROSS SECTIONAL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principal Investigator

Study Record Dates

• First Submitted: June 27, 2022
• First Posted: July 6, 2022
• Study Start: May 20, 2023
• Primary Completion: October 31, 2024
• Study Completion (Estimated): December 31, 2026
• Last Updated: May 4, 2026

Record last verified: 2026-04

Data Sharing

• IPD Sharing: Will not share

Locations

CA (1)