Clinical Trial Details
— Status: Withdrawn
Administrative data
| NCT number |
NCT03981757 |
| Other study ID # |
19.0273 |
| Secondary ID |
|
| Status |
Withdrawn |
| Phase |
N/A
|
| First received |
|
| Last updated |
|
| Start date |
January 1, 2023 |
| Est. completion date |
April 30, 2023 |
Study information
| Verified date |
February 2024 |
| Source |
University of Louisville |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Interventional
|
Clinical Trial Summary
Study of Regional cerebral Oxygenation and Brain Blood Volume changes during Carotid
Endarterectomy using the NeurOS system
Description:
1. Title of the Research Project： Study of Regional cerebral Oxygenation and Brain Blood
Volume change during Carotid Endarterectomy using the NeurOS system (COBBV-CE Trial)
2. Background/Problem Statement: The use of regional cerebral oxygenation (rSO2) monitoring
has grown clinically, even becoming the standard of care in some institutions.
Monitoring of intracranial tissue oxygenation is fundamentally possible because light in
the near infrared spectrum (700-900nm) penetrates bone, muscle, and other tissue.
Oxyhemoglobin and deoxyhemoglobin have distinct peak absorption spectra, but there is an
isobestic wavelength (i.e., wavelength for which the peak absorption of light is similar
for oxyhemoglobin and deoxyhemoglobin, approximately 810nm) for absorption by total
hemoglobin. Determination of rScO2 thus is possible with transmission of just 2
wavelengths of near-infrared spectroscopy (NIRS) to determine the relative
concentrations of oxyhemoglobin versus total hemoglobin. A decrease in rSO2 from
baseline >20% or an absolute rSO2 value <50% often is reported in clinical investigation
as representing a clinically meaningful reduction or "desaturation."
Cerebral autoregulation was found to be impaired in carotid stenosis patients. Recent
research found that NIRS allows continuous non-invasive monitoring of cerebral oxygenation
during CEA, with high sensitivity and acceptable specificity in predicting cerebral ischemia
and the need for shunting, which makes it an attractive alternative to stump pressure.
Regional cerebral oxygenation provides a clinically acceptable surrogate of cerebral blood
flow (CBF) for clinical autoregulation monitoring. Monitoring CBF autoregulation with rSO2
has many clinically attractive features, including the following: It is noninvasive,
monitoring requires little caregiver intervention, and it has sufficient resolution to
discriminate the lower autoregulatory threshold to prevent brain ischemia. On the other hand,
simply raising mean blood pressure targets, however, may not necessarily be beneficial
because for some individuals this may result in blood pressure above the upper limit of
autoregulation, which potentially could lead to cerebral hyperperfusion, increasing cerebral
embolic load and/or enhancing cerebral edema in the setting of systemic inflammatory response
to cardiac surgery. Individualizing blood pressure during CPB based on physiological
endpoints such as rSO2 monitoring, rather than empiric targets, may provide a means for
modifying the risk for renal injury and major organ morbidity and possibly mortality. In
patients undergoing combined CEA and CABG surgery, it was found that the utility of NIRS
could compliment patient selection for CEA as well as for individual patient management
during. The brain blood volume changes during CEA has not been defined and would be
significantly reduced by carotid artery clamping during CEA. Abnormalities of the circle of
Willis would contribute to reduced brain blood volume. The combination of rSO2 and cerebral
blood volume would be very helpful to prevent mal-perfusion of either side of the brain.
Postoperative delirium could happen after CEA due to reperfusion of the previously ischemic
regions of the brain, regulation of cerebral blood volume after CEA would also prove
beneficial to prevent postoperative delirium.
Problem Statement: Disposable rSO2 sensors are costly and is becoming a rate limiting factor
hindering its widespread clinical use. Reusable sensors like NeurOS cerebral oximetry are
only a fraction of cost with similar performances in healthy volunteers. We will use NeurOS
in accordance with its approved labeling and indications by FDA. CEA surgery has significant
variations and great clinical importance of cerebral oxygenation during different stages of
surgery. Blood volume changes before, during and after CEA have not been studied previously
and could provide critical information to prevent postoperative cognitive changes. The NeurOS
system calculates the sum of attenuation of two wavelengths to provide brain blood volume
index (BVI) continuously.
Patients presenting for carotid endarterectomy face two challenges during surgery. First, how
to protect the brain when the carotid artery is clamped, meaning no blood flow to that side
of the brain from this carotid artery. Second, how to prevent hyperemia when the carotid
artery is open and might provide too much blood flow to the brain. Our aim is to study the
cerebral oxygenation and brain blood volume changes during carotid endarterectomy and
identify whether they are related to clinical outcomes.
3. Objectives:
1. To study the cerebral oxygenation changes with NeurOS system and correlate desaturation
with outcomes.
2. To study the brain blood volume changes during CEA surgery and correlate with clinical
outcomes.
4. Study Design/Methodology: Patients will have NeurOS pads placed on their foreheads.
Continuous monitoring of arterial blood pressure, cerebral oxygenation and brain blood volume
index for the whole length of surgery will be recorded and saved in a USB drive for retrieval
and analysis. Key point data include: Baseline, Anesthesia Induction, Incision, Carotid
Clamping, Clamp Release and Skin Closure. These key points data will be extracted for
analysis.
1. . Sample selection and size: 100 consecutive carotid endarterectomy patients at Jewish
Hospital, Louisville, KY (6 months to recruit)
2. . Describe the proposed intervention: Apply the single use NeurOS cerebral oximetry
sensor adhesive onto patients' forehead who are going to have CEA surgery in the
operating room before anesthesia induction.
3. . Data collection procedures, instruments used, and methods for data quality control:
Anesthesia providers (attending anesthesiologists, residents and CRNAs) provide routine
anesthesia care for CEA surgery. NeurOS rSO2 reading are automatically recorded in the
VO200-NeurOS Cerebral Oximetry Monitor and the INOVS Monitor respectively. Significant
events (Baseline, Anesthesia Induction, Incision, Carotid Clamping, Clamp Release and
Skin Closure) will be marked manually by the anesthesia providers in the NeurOS system.
Brain blood volume index will be automatically recorded and retracted from the NeurOS
system once surgery is over. All data will be downloaded from the system into an
encrypted USB drive for storage and analysis. Data quality control will be ensured by
the individual system alarms for poor signals and be corrected by anesthesia providers.
4. . Unit of analysis and observation: Cerebral Oxygenation in percentage of oxyhemoglobin.
Brain blood volume index in the sum of attenuation of two wavelengths.
5. Subject Recruitment Methods: All patients presenting to Jewish Hospital for CEA surgery
will be contacted for potential recruitment on the day of surgery in the preoperative area.
6. Informed Consent Process/Complete Waiver Process: Informed consent will be provided to all
participants.
7. Research Procedures:
In all consented patients, baseline cerebral oxygenation and brain blood volume index will be
obtained at room air or baseline oxygen requirement level in the NeurOS systems. Both NeurOS
rSO2 and brain blood volume indexes will be continuously recorded and saved in the respective
system throughout the whole CEA surgery. General anesthesia will be induced by using O2
administered via face mask and IV fentanyl 1μg/ kg, propofol 2-3mg/kg and rocuronium 1mg/kg.
Maintenance of anesthesia was achieved with inhaled isoflurane in air/oxygen mixture and
muscle relaxation using intermittent boluses of rocuronium. Fentanyl will be used as
supplemental analgesia. Normocapnic ventilation was maintained. Upon completion of surgery,
titrated doses of protamine will be administered to reverse the anticoagulant action of
heparin, targeting to achieve baseline preoperative Activated clotting Time.
After the surgery, all rSO2 and brain blood volume index data are downloaded into an
encrypted USB drive for analysis and storage.
8. Minimizing Risks:
1. All HIPPA related information will be stored in a private computer in a password
protected computer.
2. Cleaning of cables, monitors and reusable equipment are performed after each use.
3. Standard electrical precautions will be followed to prevent electrical shock to
providers and patients.
9. Plan for Analysis of Results:
- Trend graphs of NeurOS brain blood volume index, arterial blood pressure and cerebral
oxygenation will be plotted together to identify correlations among them.
- Cerebral oxygenation and brain blood volume index deviation from the baseline at each
key point will be analyzed to identify whether these critical moments affect cerebral
oxygenation and the brain blood volume. Clinical outcomes data will be collected on
30-day mortality and strokes to identify whether abnormal cerebral oxygenation and brain
blood volume directly (too high or too low, Area Under or Above the Curve) affects
clinical outcomes.
- Programs to be used for data analysis: Software R
10. Research Materials, Records, and Privacy: Identify the sources of research material
obtained from individually identifiable living human subjects: Prospective noninvasive
data on cerebral oxygenation and brain blood volume during cardiac surgery. Please see
data collection form.
Indicate what information (records, data, etc.) will be recorded and whether use will be made
of existing records or data: Cerebral oxygenation and brain blood volume. They will be
recorded in the medical charts.
Explain why this information is needed to conduct the study: These data are necessary to
identify outcomes for these patients.
Specify how the data will be de-identified (if applicable), who has access to the data, where
the data will be stored and how the researcher will protect both the data with respect to
privacy and confidentiality. Address physical security measures (e.g., locked facility,
limited access); data security (e.g., password-protection, data encryption); safeguards to
protect identifiable research information (e.g., coding or links): Once required information
is collected, HIPPA information will be deleted. All HIPPA related information will be stored
in a private computer in a password protected computer. No links will be provided to the
public.
