Cerebral AutoregulationFLOWMAPCANCT05681741
Impact of Cardiopulmonary Bypass Flow on Cerebral Autoregulation
A study testing current versus high pump flow in people with Cerebral Autoregulation and Cardiopulmonary Bypass, run by Clinique de la Sauvegarde at 1 site in France.
Trial summary
Cerebral autoregulation is defined by the capacity of the brain to maintain a constant cerebral blood flow (CBF) despite variations of arterial pressure. However, when the arterial pressure is below a critical threshold, cerebral blood decreases. Read more about this study
- Who is it for?
- Ages 18 to 90 years
- Conditions the study is for
- Cerebral Autoregulation, Cardiopulmonary Bypass, Mean Arterial Pressure
- What is being tested?
- current versus high pump flow
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 40 participants
- Where
- 1 siteFrance
- Study dates
- 8 Jan 2023to 12 Sep 2023
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 90 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Patient, male or female, over the age of 18
- Patient scheduled to undergo valvular heart surgery with planned CPB
- Patient with a Euroscore below 7%
- Patient affiliated or entitled to a social security scheme
- Patient having received informed information about the study and having signed a free and informed consent to participate in the study
Who cannot join
- Patient with untreated or uncontrolled severe hypertension despite treatment
- Patient with chronic renal failure, with glomerular filtration < 30 mL/min/1.73m² or requiring a kidney transplant
- Patient with left ventricular ejection fraction < 40%
- Patient with a history of ischemic stroke
- Patient having or about to benefit from renal vascular surgery
- Patient with preoperative sepsis
Show all 12Show fewer
- Patient who required a norepinephrine infusion within 24 hours before surgery
- Patient presenting with an inaccessible temporal Doppler window
- Patient candidate for emergency surgery
- Pregnant, parturient or breastfeeding woman
- Patient with preoperative uni or bilateral carotid stenosis > 50%
- Protected patient: adult under guardianship, curators or other legal protection, deprived of liberty by judicial or administrative decision
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Impact of Cardiopulmonary Bypass Flow on Cerebral Autoregulation in Cardiac Surgery, a Cross-over Study
Cerebral autoregulation is defined by the capacity of the brain to maintain a constant cerebral blood flow (CBF) despite variations of arterial pressure. However, when the arterial pressure is below a critical threshold, cerebral blood decreases.
This critical threshold is called the lower limit of cerebral autoregulation (LLA).
Read more
Cardiopulmonary bypass is a unique environment wherein systemic blood flow is totally controlled by the cardiopulmonary bypass pump. High pump flows combined with low arterial pressures has been shown to not compromise neurologic postoperative outcomes.
Our hypothesis is that that LLA may depend on the cardiopulmonary bypass flow, ie the LLA may decrease when the cardiopulmonary bypass flow increases, explaining why low arterial pressure may be well tolerated.
Read the detailed description
Cerebral tissue perfusion is partly ensured by cardiac output and arterial pressure. In cardiac surgery, and especially during bypass surgery, one of the main objectives is to maintain sufficient blood flow and an optimal mean arterial pressure (MAP) to limit the deleterious consequences of organ hypoperfusion. To have a physiological regional organ blood flow, some organs, such as the brain, need a minimum MAP threshold (the lower limit of autoregulation, LLA) to ensure a constant cerebral blood flow (CBF). This is known as the cerebral autoregulation (CA). As the brain is at high risk of ischemia and definitive functional consequences in case of cerebral hypoperfusion, maintaining MAP above the LLA of the brain limit the deleterious postoperative neurological outcome.
CA can be determined by continuously calculating the correlation between MAP and CBF. CBF is assessed by continuous monitoring of the middle cerebral artery velocity (mV). moving Pearson correlation coefficient between 30 consecutive, paired MAP and cerebral blood flow velocity values will be calculated to generate the mean velocity index (Mx). The Blood pressure in the autoregulation range is indicated by an Mx value that approaches zero (there is no correlation between flow velocity and MAP), whereas an Mx approaching 1 indicates dysregulated cerebral blood flow (flow velocity and MAP are correlated). A value of 0.4 is accepted as the threshold of CA corresponding to the LLA.
During cardiopulmonary bypass (CPB), MAP is physiologically related to bypass flow and systemic vascular resistance. The adjustment of MAP during CPB is therefore achieved by the administration of vasoconstrictors or vasodilators as well as by the variations of the pump flow.
This research assumes that a change in the pump flow rate will lead to a change in the LLA. Therefore, if the flow rate is higher, it is possible that the LLA will be lower.
In this randomized trial, two different rates of pump flow will be compared with respect to LLA testing.
Regional brain oxygen saturation, assessed by near-infrared spectroscopy will also be monitored during surgery.
- Being tested
- current versus high pump flow
- Keywords
- FlowMapca
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
current versus high pump flowProcedure or surgery
during each phase of randomized pump flow, arterial pressure will be increased from 40 to 90 mmHg with vasodilators and/or vasoconstrictors
| Study group | Role | What they receive |
|---|---|---|
| current pump flow (between 2 and 2.4 l/min/m²) | Sham comparator | the pump flow will be constant during this randomized phase Receives: Procedure: current versus high pump flow |
| high pump flow (between 2.6 and 3 l/min/m²) | Active comparator | the pump flow will be constant during this randomized phase Receives: Procedure: current versus high pump flow |
What is being measured
The primary outcome is the main question the study is designed to answer.
measurement of MAP LLA (mmHg)
Determination of MAP LLA according to the calculation of the mean velocity index
Measured: 15 to 25 min during the procedure
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted12 Jan 2023
- Study start8 Jan 2023
- Primary completion3 Jul 2023
- Study completion12 Sep 2023
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Cerebral AutoregulationStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Diagnosis
- Allocation
- Randomised
- Intervention model
- Crossover
- Model description
- parallel affectation
- Masking
- Double blind
- Who is masked
- Participant, Outcomes assessor
- Enrolment
- 40 participants (actual)
Sponsor and investigators
- Lead sponsor
- Clinique de la Sauvegarde
- Sponsor type
- University, hospital or other
- Collaborators
- GCS Ramsay Santé pour l'Enseignement et la Recherche
- Responsible party
- Principal investigator, Johanne Beuvelot, Clinique de la Sauvegarde
- Investigators
- Olivier Desebbe, MD, Principal investigator, Clinique de la Sauvegarde
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05681741
- Sponsor's protocol ID
- Ramsay Sante Sauvegarde Clinic
- Acronym
- FLOWMAPCA
- Status last verified
- Sep 2023
- First submitted
- 28 Dec 2022
- Last updated
- 14 Sep 2023
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Desebbe O, Berna A, Joosten A, Raphael D, Malapert G, Rolo D, Taccone FS, Gergele L. Impact of cardiopulmonary bypass flow on the lower limit of cerebral autoregulation during cardiac surgery: a randomized cross-over pilot study. J Clin Monit Comput. 2025 Jun;39(3):571-580. doi: 10.1007/s10877-025-01290-2. Epub 2025 Apr 12.
PubMed 40220213
Study at a glance
From the registry record, last updated by the sponsor on 14 Sep 2023. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Impact of Cardiopulmonary Bypass Flow on Cerebral Autoregulation in Cardiac Surgery, a Cross-over Study
- ClinicalTrials.gov ID
- NCT05681741
- Acronym / sponsor ID
- FLOWMAPCA / Ramsay Sante Sauvegarde Clinic
- Keywords
- FlowMapca
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 40 participants (actual)
- Lead sponsor
- Clinique de la SauvegardeUniversity, hospital or other
- Collaborators
- GCS Ramsay Santé pour l'Enseignement et la Recherche
- Study start
- 8 Jan 2023 (actual)
- Primary completion
- 3 Jul 2023 (actual)
- Study completion
- 12 Sep 2023 (actual)
- First posted
- 12 Jan 2023 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Cerebral autoregulation is defined by the capacity of the brain to maintain a constant cerebral blood flow (CBF) despite variations of arterial pressure. However, when the arterial pressure is below a critical threshold, cerebral blood decreases.
This critical threshold is called the lower limit of cerebral autoregulation (LLA).
Cardiopulmonary bypass is a unique environment wherein systemic blood flow is totally controlled by the cardiopulmonary bypass pump. High pump flows combined with low arterial pressures has been shown to not compromise neurologic postoperative outcomes.
Our hypothesis is that that LLA may depend on the cardiopulmonary bypass flow, ie the LLA may decrease when the cardiopulmonary bypass flow increases, explaining why low arterial pressure may be well tolerated.
Detailed description
Cerebral tissue perfusion is partly ensured by cardiac output and arterial pressure. In cardiac surgery, and especially during bypass surgery, one of the main objectives is to maintain sufficient blood flow and an optimal mean arterial pressure (MAP) to limit the deleterious consequences of organ hypoperfusion. To have a physiological regional organ blood flow, some organs, such as the brain, need a minimum MAP threshold (the lower limit of autoregulation, LLA) to ensure a constant cerebral blood flow (CBF). This is known as the cerebral autoregulation (CA). As the brain is at high risk of ischemia and definitive functional consequences in case of cerebral hypoperfusion, maintaining MAP above the LLA of the brain limit the deleterious postoperative neurological outcome.
CA can be determined by continuously calculating the correlation between MAP and CBF. CBF is assessed by continuous monitoring of the middle cerebral artery velocity (mV). moving Pearson correlation coefficient between 30 consecutive, paired MAP and cerebral blood flow velocity values will be calculated to generate the mean velocity index (Mx). The Blood pressure in the autoregulation range is indicated by an Mx value that approaches zero (there is no correlation between flow velocity and MAP), whereas an Mx approaching 1 indicates dysregulated cerebral blood flow (flow velocity and MAP are correlated). A value of 0.4 is accepted as the threshold of CA corresponding to the LLA.
During cardiopulmonary bypass (CPB), MAP is physiologically related to bypass flow and systemic vascular resistance. The adjustment of MAP during CPB is therefore achieved by the administration of vasoconstrictors or vasodilators as well as by the variations of the pump flow.
This research assumes that a change in the pump flow rate will lead to a change in the LLA. Therefore, if the flow rate is higher, it is possible that the LLA will be lower.
In this randomized trial, two different rates of pump flow will be compared with respect to LLA testing.
Regional brain oxygen saturation, assessed by near-infrared spectroscopy will also be monitored during surgery.
Study design
- Primary purpose
- Diagnosis
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Double blind (participant, outcomes assessor)
- Number of arms
- 2
- Model description
- parallel affectation
| Arm | Type | Receives |
|---|---|---|
| current pump flow (between 2 and 2.4 l/min/m²) | Sham comparator | Procedure: current versus high pump flowthe pump flow will be constant during this randomized phase |
| high pump flow (between 2.6 and 3 l/min/m²) | Active comparator | Procedure: current versus high pump flowthe pump flow will be constant during this randomized phase |
Who may qualify
- Ages
- 18 to 90 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (5 listed)
- Patient, male or female, over the age of 18
- Patient scheduled to undergo valvular heart surgery with planned CPB
- Patient with a Euroscore below 7%
- Patient affiliated or entitled to a social security scheme
- Patient having received informed information about the study and having signed a free and informed consent to participate in the study
Key exclusion criteria (12 listed)
- Patient with untreated or uncontrolled severe hypertension despite treatment
- Patient with chronic renal failure, with glomerular filtration < 30 mL/min/1.73m² or requiring a kidney transplant
- Patient with left ventricular ejection fraction < 40%
- Patient with a history of ischemic stroke
- Patient having or about to benefit from renal vascular surgery
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| current versus high pump flowduring each phase of randomized pump flow, arterial pressure will be increased from 40 to 90 mmHg with vasodilators and/or vasoconstrictors | Procedure or surgery | current pump flow (between 2 and 2.4 l/min/m²), high pump flow (between 2.6 and 3 l/min/m²) |
Primary outcome
measurement of MAP LLA (mmHg)
Time frame: 15 to 25 min during the procedure
Determination of MAP LLA according to the calculation of the mean velocity index
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 14 Sep 2023.
- Derived from this study: PubMed 40220213Desebbe O, Berna A, Joosten A, Raphael D, Malapert G, Rolo D, Taccone FS, Gergele L. Impact of cardiopulmonary bypass flow on the lower limit of cerebral autoregulation during cardiac surgery: a randomized cross-over pilot study. J Clin Monit Comput. 2025 Jun;39(3):571-580. doi: 10.1007/s10877-025-01290-2. Epub 2025 Apr 12.
- Individual participant dataSharing planned: No
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Homeostasis
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Olivier Desebbe, MD principal investigator
Clinique de la Sauvegarde
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing current versus high pump flow in people with Cerebral Autoregulation and Cardiopulmonary Bypass, run by Clinique de la Sauvegarde at 1 site in France.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 12 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 14 Sep 2023. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in France. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
measurement of MAP LLA (mmHg) (time frame: 15 to 25 min during the procedure). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT05681741, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 14 Sep 2023.