Cerebral Blood Flow During Hemodialysis

Not Applicable

Completed

Brief Summary: The purpose of this study is to evaluate the effect of the hemodialysis procedure on cerebral blood flow (CBF) in elderly maintenance hemodialysis (HD) patients. The investigators hypothesize that HD induced blood pressure changes are associated with a fall in global and/or regional CBF during HD. Second, the investigators hypothesize that near infrared spectroscopy (NIRS) will correlate with CBF measured by\[15O\]H2O PET.

Detailed Description: The investigators aim to include 14 participants. Each participant will undergo a single HD study session in the PET center of the UMCG. During this study session, each participant will undergo three gated \[15O\]H2O PET-CT scans before, during (after 20 minutes) and at the end of the HD session. NIRS will be used to measure cerebral tissue regional oxygen saturation (rSO2) during the HD study session. INVOS (In Vivo Optical Spectroscopy), a monitoring device, will be used to measure rSO2, with sensors placed bilaterally on the patient forehead. Participants will further undergo a MRI scan of the brain, bilateral carotid artery duplex echosonography, cognitive testing, blood pressure and heart rate measurements during the HD study session, and laboratory measurements during the HD study session.

Recruitment & Eligibility

Inclusion Criteria

Adult, age ≥ 65 years, HD patients who have been treated with maintenance HD, of which at least 6 patients for a longer period of time (>1 year).
Patients must have an arteriovenous fistula without recirculation
The hemoglobin value must be in the target range (6.2 - 8mmol/l) since at least 1 month

Exclusion Criteria

The absence of informed consent
Diagnosis of dementia, hydrocephalus, history of raised intracranial pressure, significant (>70%) carotid artery stenosis, end-stage liver disease.
Actively treated cancer
Actual hospital admission at timing of HD study session
MRI incompatible implants in the body or any other contraindication for MRI
Claustrophobia
The refusal to be informed of significant carotid artery stenosis or structural brain abnormalities that could be detected during the study.

Arm && Interventions

Group	Intervention	Description
CBF change during hemodialysis	NIRS (Invos)	\[15O\]H2O PET-CT scan and NIRS (Invos)
CBF change during hemodialysis	[15O]H2O PET-CT scan	\[15O\]H2O PET-CT scan and NIRS (Invos)

Primary Outcome Measures

Name	Time	Method
Change in CBF From Baseline (Before Start of the Hemodialysis Study Session), at 20 Minutes, and at the End of the Hemodialysis Study Session, Measured by [15O]H2OPET-CT	at t= -5 minutes, t= 20 minutes, and at t=220 minutes.The change from baseline (-5min) to the end of hemodialysis (220min) is reported.

Secondary Outcome Measures

Name	Time	Method
Change in rSO2 From Baseline (Before Start of the Hemodialysis Study Session), at 20 Minutes, and at the End of the Hemodialysis Study Session, Measured by NIRS	at t= -5 minutes, t= 20 minutes, and at t=220 minutes.The start of dialysis was considered as t=0. Therefore, baseline is t=-5minutes.	Change in rSO2, between baseline (-5 minutes) and the end of the hemodialysis (t=220 minutes) study session.