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Cerebral Oxygen SaturationNCT01424800

Influence of Variations in Systemic Blood Flow and Blood Pressure on Cerebral Oxygenation Measured by Cerebral Oximetry

A study testing A disposable NIRS (near-infrared spectroscopy) sensor will be applied on the patient's forehead for continuous registration of the cerebral oxygen saturation. in people with Cerebral Oxygen Saturation, run by University Hospital, Ghent at 1 site in Belgium.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

This study emphasizes on the influence of changes in systemic flow and systemic mean arterial blood pressure (MAP) during cardiopulmonary bypass (CPB) on cerebral oxygenation assessed by near-infrared spectroscopy (NIRS). Read more about this study

Who is it for?
Ages 21 years and older
Conditions the study is for
Cerebral Oxygen Saturation
What is being tested?
A disposable NIRS (near-infrared spectroscopy) sensor will be applied on the patient's forehead for continuous registration of the cerebral oxygen saturation.
Type of treatment
Medical device
Could I receive a placebo?
No, everyone receives an active treatment
How many people
34 participants
Where
1 siteBelgium
Study dates
Jul 2011to Dec 2011
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 21 years and older
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • Age 21-100 years, scheduled for elective cardiac surgery, written informed consent.

Who cannot join

  • History of cerebrovascular disease or symptomatic carotid artery stenosis.

Trial locations and contacts

1 site in 1 country.

Belgium1 site
  • University Hospital Ghent

    Ghent, 9000

Other trials in Belgium

About this study

This study emphasizes on the influence of changes in systemic flow and systemic mean arterial blood pressure (MAP) during cardiopulmonary bypass (CPB) on cerebral oxygenation assessed by near-infrared spectroscopy (NIRS). The aim of the study is to determine whether variations in systemic flow, in MAP, or in both variables at the same time have the greatest impact on the cerebral oxygen saturation.

Read the detailed description

Cerebral autoregulation is defined as the whole of regulatory mechanisms that maintains a constant cerebral blood flow (CBF) during changes in cerebral perfusion pressure (CPP). Cerebrovascular resistance adjusts when CPP changes in order to keep CBF constant. In contrast with this concept of pressure-mediated autoregulation, it is suggested that cerebral autoregulation is focused on maintaining homeostasis of the cerebral metabolic rate of oxygen (CMRO2). We assume that both flow and pressure contribute to the regulation of CMRO2.

Assessment of cerebral oxygenation - Cerebral oxygen saturation will be monitored with near-infrared spectroscopy (NIRS). NIRS allows simple, continuous and non-invasive measurement of cerebral oxygen saturation (ScO2)and primarily cerebral venous saturation. Cerebral oxygen saturation will be monitored with a FDA-approved devices: INVOS 5100 (Somanetics Corporation, Troy, MI, USA).

To study the effects of changes in pressure and in flow, we need a condition where we can alter these variables separately and in a controlled manner. Therefore this study will be performed during cardiopulmonary bypass (CPB). Pressure will be varied with the administration of routinely used vasoactive substances, while flow will be varied by altering the pump flow manually. We hypothesize that if we change one parameter (pressure or flow), a compensatory mechanism will preserve the CMRO2 homeostasis, with no change in ScO2. On the other hand, if we change both pressure and flow, we expect a significant effect on cerebral oxygen saturation. With 20 % changes in pressure and/or flow, we expect a change in NIRS values of approximately 5 %. Previous studies showed that this kind of reduction is well tolerated by the brain. This means that the proposed changes are within the normal physiological range, and will have no adverse effects.

Being tested
A disposable NIRS (near-infrared spectroscopy) sensor will be applied on the patient's forehead for continuous registration of the cerebral oxygen saturation.

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • A disposable NIRS (near-infrared spectroscopy) sensor will be applied on the patient's forehead for continuous registration of the cerebral oxygen saturation.Device

    When the patient is on CPB, pressure and/or flow will be changed while continuously measuring ScO2. Temperature, CO2 , arterial oxygen content, hematocrit and anesthesia will be kept constant during the measurements. First, baseline MAP (mean arterial pressure), baseline ScO2 and baseline central venous oxygen saturation (SvO2) are determined. With the interventions, we will induce a change of 20% in MAP and/or flow. This is within the normal range during operations. Changes in blood pressure will be obtained by the use of vasoactive agents (sodiumnitroprusside for blood pressure decrease and phenylephrine for blood pressure increase). Flow is regulated by manual control of the pump flow. Values of the different variables will be obtained after a 5 min stabilisation period. Flow/pressure interventions will be randomized.

Study groups in NCT01424800
Study groupRoleWhat they receive
change in blood pressure and blood flowExperimental34 patients will form the experimental group, in which changes of blood pressure and blood flow will be induced and monitored.
Receives: Device: A disposable NIRS (near-infrared spectroscopy) sensor will be applied on the patient's forehead for continuous registration of the cerebral oxygen saturation.

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Blood flow

    Changes in blood flow during cerebral oxygen saturation measured with NIRS, during surgery when the patient is on cardiopulmonary bypass.

    Measured: during the entire surgery

  2. Blood pressure

    Changes in blood pressure during cerebral oxygen saturation measured with NIRS, during surgery when the patient is on cardiopulmonary bypass.

    Measured: during the entire surgery

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted29 Aug 2011 (estimated)
  2. Study startJul 2011
  3. Primary completionDec 2011
  4. Study completionDec 2011

Resources

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
Basic science
Allocation
Not applicable
Intervention model
Single group
Masking
None (open label)
Enrolment
34 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT01424800
Sponsor's protocol ID
2011/208
Status last verified
Mar 2012
First submitted
22 Aug 2011
Last updated
6 Mar 2012
Results posted
No
Data monitoring committee
No

Questions about this trial

What is this clinical trial studying?

A study testing A disposable NIRS (near-infrared spectroscopy) sensor will be applied on the patient's forehead for continuous registration of the cerebral oxygen saturation. in people with Cerebral Oxygen Saturation, run by University Hospital, Ghent at 1 site in Belgium.

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 1 inclusion and 1 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 6 Mar 2012. 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 Belgium. 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. 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?

Blood flow (time frame: during the entire surgery). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?
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 6 Mar 2012.

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