Regional AnesthesiaCBF-TCDNCT04642612
Cerebral Blood Flow Evaluation With Trancranial Doppler After Interscalene Nerve Block
An observational study of Regional Anesthesia and Horner Syndrome, run by Stanford University at 1 site in United States.
Trial summary
The purpose of this study is to assess cerebral blood flow velocity (CBFV) following regional anesthesia for shoulder surgery. The results of this study will help to further understand the physiologic effect of the interscalene nerve block on cerebral blood flow. Read more about this study
- Who is it for?
- Ages 18 to 85 yearsHealthy volunteers can take part
- Conditions the study is for
- Regional Anesthesia, Horner Syndrome, Cerebral Blood Flow
- What is being tested?
- TCD Measurement
- Type of treatment
- Medical device
- How many people
- 10 participants
- Where
- 1 siteUnited States
- Study dates
- 4 Mar 2021to 30 Jul 2021
- Phase
- Observational
- 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 85 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Study population: Patients undergoing orthopedic surgery with an indication for preoperative insertion of interscalene nerve block, aged 18-85 years old, and give consent to participating in study.
Who may be able to join
- Patients undergoing orthopedic surgery and with an indication for preoperative insertion of interscalene nerve block
- 18-85 years old
- Give consent to participate in study
Who cannot join
- Cannot give consent
- Patients who are clinically unstable or require urgent/emergent intervention
Trial locations and contacts
1 site in 1 country.
United States1 site
Stanford University School of Medicine
Stanford, California, 94304
About this study
Official title: Cerebral Blood Flow Evaluation With Trancranial Doppler After Unilateral Interscalene Nerve Block: Observational Prospective Study
The purpose of this study is to assess cerebral blood flow velocity (CBFV) following regional anesthesia for shoulder surgery. The results of this study will help to further understand the physiologic effect of the interscalene nerve block on cerebral blood flow.
Read the detailed description
Traditionally, cerebral blood flow (CBF) is believed to decline when mean arterial pressure (MAP) is below the lower limit of cerebral autoregulation. Cerebral blood flow autoregulation refers to the capacity of the central nervous system to maintain blood flow within a wide range of mean arterial blood pressure.
The habitual thinking is that the brain is perfused merely dependent by the blood pressure and that above or below the limits of cerebral autoregularion CBF is pressure passive. Despite this notion, there is evidence showing that parameters other than MAP influence cerebral hemodynamics independent of cerebral autoregulation. One of the physiologic processes that contribute to CBF regulation is cardiac output (CO). However, exactly how an alteration in CO, in the face of a stable blood pressure, leads to a change in CBF is not entirely clear.
One of the suggested mechanisms in play is the sympathetic nervous system (SNS)-mediated vasoconstriction of extracranial and proximal intracranial vessels. Cerebral arteries are abundantly innervated by sympathetic nerve fibers originating from the superior cervical ganglion. Studies have shown that CBF reduction is attenuated by pharmacologic blockade or extirpation of the cervical sympathetic chain.
The anesthetic protocol for patients undergoing major shoulder surgery include an interscalene nerve block (ISNB) combined with general anesthesia in the sitting position. The ISNB involves injecting local anesthetic at the level of the cervical spinal roots. One of the most common side effects encountered after ISNB is Horner syndrome, which is characterized by ptosis, myosis, and enopthalmia. Horner's syndrome results from the diffusion of the local anesthetic solution to the ipsilateral sympathetic cervical chain (stellate ganglion). The presence of Horner's syndrome indicates spread of local anesthetic to the sympathetic chain.
Whether this degree of sympatholytic following interscalene block is associated with an observable change in CBF is unknown. Studies in baboon have shown that cervical surgical sympathectomy maintained CBF in the face of hemorrhagic hypotension and CBF did not decrease until MAP was 35% of the baseline value. These results suggest that sympathectomy induced by the block of the sympathetic chain by the local anesthetic injected for the ISNB might alter CBF. Therefore, the aim of our study is to evaluate the effect of unilateral interscalene nerve block on CBF by measuring CBF velocity non-invasively with Transcranial doppler (TCD).
- Conditions
- Regional Anesthesia, Horner Syndrome, Cerebral Blood Flow
- Being tested
- TCD Measurement
- Medical subject headings
- Horner Syndrome
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
TCD MeasurementDevice
CBFV measurements will be acquired continuously with the patient supine and the head neutral. Analysis of CBFV measurements will be undertaken at 3 timepoints:
- Patient awake and supine in the holding area
- After sedation
- After interscalene nerve block
| Study group | Role | What they receive |
|---|---|---|
| Treatment Arm | Patients ages 18-85 years old presenting with orthopedic shoulder surgery with indication to receive preoperative insertion of interscalene nerve block. Receives: Device: TCD Measurement |
What is being measured
The primary outcome is the main question the study is designed to answer.
Cerebral Blood Flow Velocity before and after interscalene nerve block
The TCD automatically measures blood flow velocity in the main cerebral arteries of the circle of Willis. We will target the MCA which is the closest to the temporal bone therefore the most easily accessible for insonation and monitoring. We will do a bilateral monitoring.
Measured: baseline, after 30 minutes
Secondary outcomes (9)
Systolic, diastolic, mean blood pressure changes before and after interscalene nerve block
Will be measured before/during/after interscalene nerve block placement
Measured: baseline, after 30 minutes
Heart Rate
Will be measured before/during/after interscalene nerve block placement
Measured: baseline, after 30 minutes
Respiratory Rate changes before and after interscalene nerve block
Will be measured before/during/after interscalene nerve block placement
Measured: baseline, after 30 minutes
EtCO2 changes before and after interscalene nerve block
Will be measured before/during/after interscalene nerve block placement
Measured: baseline, after 30 minutes
SpO2 changes before and after interscalene nerve block
Will be measured before/during/after interscalene nerve block placement
Measured: baseline, after 30 minutes
Type of local anesthetic
Local anesthetic characteristics will be collected after interscalene block placement.
Measured: 30 minutes after the nerve block
Position of the needle on the cervical trunk for interscalene nerve block
Needle position for interscalene nerve block insertion will be assessed at the time of interscalene block placement
Measured: Baseline
Volume of of local anesthetic
Local anesthetic characteristics will be collected after interscalene block placement.
Measured: 30 minutes after the nerve block
Concentration of local anesthetic
Local anesthetic characteristics will be collected after interscalene block placement.
Measured: 30 minutes after the nerve block
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted24 Nov 2020
- Study start4 Mar 2021
- Primary completion19 May 2021
- Study completion30 Jul 2021
Why it stopped: Study not properly designed for outcome measure
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (5)Papers the sponsor has linked to this study.
- Other trials for Regional AnesthesiaStudies of the same condition, open and under way.
- More trials run by Stanford UniversityThe sponsor's other registered studies.
- 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
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 10 participants (actual)
Sponsor and investigators
- Lead sponsor
- Stanford University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Anna Maria Bombardieri, Stanford University
- Investigators
- Anna Maria Bombardieri, MD, PhD, Principal investigator, Stanford University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04642612
- Sponsor's protocol ID
- 59007
- Acronym
- CBF-TCD
- Status last verified
- Sep 2021
- First submitted
- 2 Nov 2020
- Last updated
- 16 Sep 2021
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- Yes
Publications
Meng L, Hou W, Chui J, Han R, Gelb AW. Cardiac Output and Cerebral Blood Flow: The Integrated Regulation of Brain Perfusion in Adult Humans. Anesthesiology. 2015 Nov;123(5):1198-208. doi: 10.1097/ALN.0000000000000872.
PubMed 26402848Drummond JC. Cardiac Output: The Neglected Stepchild of the Cerebral Blood Flow Physiology Family. J Neurosurg Anesthesiol. 2020 Apr;32(2):93-94. doi: 10.1097/ANA.0000000000000677. No abstract available.
PubMed 31972625ter Laan M, van Dijk JM, Elting JW, Staal MJ, Absalom AR. Sympathetic regulation of cerebral blood flow in humans: a review. Br J Anaesth. 2013 Sep;111(3):361-7. doi: 10.1093/bja/aet122. Epub 2013 Apr 24.
PubMed 23616589Fitch W, MacKenzie ET, Harper AM. Effects of decreasing arterial blood pressure on cerebral blood flow in the baboon. Influence of the sympathetic nervous system. Circ Res. 1975 Nov;37(5):550-7. doi: 10.1161/01.res.37.5.550.
PubMed 153Seltzer JL. Hoarseness and Horner's syndrome after interscalene brachial plexus block. Anesth Analg. 1977 Jul-Aug;56(4):585-6. doi: 10.1213/00000539-197707000-00033. No abstract available.
PubMed 560150
Study at a glance
From the registry record, last updated by the sponsor on 16 Sep 2021. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Cerebral Blood Flow Evaluation With Trancranial Doppler After Unilateral Interscalene Nerve Block: Observational Prospective Study
- ClinicalTrials.gov ID
- NCT04642612
- Acronym / sponsor ID
- CBF-TCD / 59007
- Conditions
- Regional Anesthesia, Horner Syndrome, Cerebral Blood Flow
- Study type
- Observational
- Recruitment status
- TerminatedReason stopped: Study not properly designed for outcome measure
- Enrolment
- 10 participants (actual)
- Lead sponsor
- Stanford UniversityUniversity, hospital or other
- Study start
- 4 Mar 2021 (actual)
- Primary completion
- 19 May 2021 (actual)
- Study completion
- 30 Jul 2021 (actual)
- First posted
- 24 Nov 2020 (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.
The purpose of this study is to assess cerebral blood flow velocity (CBFV) following regional anesthesia for shoulder surgery. The results of this study will help to further understand the physiologic effect of the interscalene nerve block on cerebral blood flow.
Detailed description
Traditionally, cerebral blood flow (CBF) is believed to decline when mean arterial pressure (MAP) is below the lower limit of cerebral autoregulation. Cerebral blood flow autoregulation refers to the capacity of the central nervous system to maintain blood flow within a wide range of mean arterial blood pressure.
The habitual thinking is that the brain is perfused merely dependent by the blood pressure and that above or below the limits of cerebral autoregularion CBF is pressure passive. Despite this notion, there is evidence showing that parameters other than MAP influence cerebral hemodynamics independent of cerebral autoregulation. One of the physiologic processes that contribute to CBF regulation is cardiac output (CO). However, exactly how an alteration in CO, in the face of a stable blood pressure, leads to a change in CBF is not entirely clear.
One of the suggested mechanisms in play is the sympathetic nervous system (SNS)-mediated vasoconstriction of extracranial and proximal intracranial vessels. Cerebral arteries are abundantly innervated by sympathetic nerve fibers originating from the superior cervical ganglion. Studies have shown that CBF reduction is attenuated by pharmacologic blockade or extirpation of the cervical sympathetic chain.
The anesthetic protocol for patients undergoing major shoulder surgery include an interscalene nerve block (ISNB) combined with general anesthesia in the sitting position. The ISNB involves injecting local anesthetic at the level of the cervical spinal roots. One of the most common side effects encountered after ISNB is Horner syndrome, which is characterized by ptosis, myosis, and enopthalmia. Horner's syndrome results from the diffusion of the local anesthetic solution to the ipsilateral sympathetic cervical chain (stellate ganglion). The presence of Horner's syndrome indicates spread of local anesthetic to the sympathetic chain.
Whether this degree of sympatholytic following interscalene block is associated with an observable change in CBF is unknown. Studies in baboon have shown that cervical surgical sympathectomy maintained CBF in the face of hemorrhagic hypotension and CBF did not decrease until MAP was 35% of the baseline value. These results suggest that sympathectomy induced by the block of the sympathetic chain by the local anesthetic injected for the ISNB might alter CBF. Therefore, the aim of our study is to evaluate the effect of unilateral interscalene nerve block on CBF by measuring CBF velocity non-invasively with Transcranial doppler (TCD).
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Treatment Arm | – | Device: TCD MeasurementPatients ages 18-85 years old presenting with orthopedic shoulder surgery with indication to receive preoperative insertion of interscalene nerve block. |
Who may qualify
- Ages
- 18 to 85 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
- Study population
- Patients undergoing orthopedic surgery with an indication for preoperative insertion of interscalene nerve block, aged 18-85 years old, and give consent to participating in study.
Key inclusion criteria (3 listed)
- Patients undergoing orthopedic surgery and with an indication for preoperative insertion of interscalene nerve block
- 18-85 years old
- Give consent to participate in study
Key exclusion criteria (2 listed)
- Cannot give consent
- Patients who are clinically unstable or require urgent/emergent intervention
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 |
|---|---|---|
| TCD MeasurementCBFV measurements will be acquired continuously with the patient supine and the head neutral. Analysis of CBFV measurements will be undertaken at 3 timepoints: 1. Patient awake and supine in the holding area 2. After sedation 3. After interscalene nerve block | Device | Treatment Arm |
Primary outcome
Cerebral Blood Flow Velocity before and after interscalene nerve block
Time frame: baseline, after 30 minutes
The TCD automatically measures blood flow velocity in the main cerebral arteries of the circle of Willis. We will target the MCA which is the closest to the temporal bone therefore the most easily accessible for insonation and monitoring. We will do a bilateral monitoring.
9 secondary outcomes
Systolic, diastolic, mean blood pressure changes before and after interscalene nerve block
Time frame: baseline, after 30 minutes
Heart Rate
Time frame: baseline, after 30 minutes
Respiratory Rate changes before and after interscalene nerve block
Time frame: baseline, after 30 minutes
EtCO2 changes before and after interscalene nerve block
Time frame: baseline, after 30 minutes
SpO2 changes before and after interscalene nerve block
Time frame: baseline, after 30 minutes
Type of local anesthetic
Time frame: 30 minutes after the nerve block
Position of the needle on the cervical trunk for interscalene nerve block
Time frame: Baseline
Volume of of local anesthetic
Time frame: 30 minutes after the nerve block
Concentration of local anesthetic
Time frame: 30 minutes after the nerve block
Results and safety
The study was stopped early (reason given: Study not properly designed for outcome measure). Results are not available in the source record.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 16 Sep 2021.
- Background: PubMed 26402848Meng L, Hou W, Chui J, Han R, Gelb AW. Cardiac Output and Cerebral Blood Flow: The Integrated Regulation of Brain Perfusion in Adult Humans. Anesthesiology. 2015 Nov;123(5):1198-208. doi: 10.1097/ALN.0000000000000872.
- Background: PubMed 31972625Drummond JC. Cardiac Output: The Neglected Stepchild of the Cerebral Blood Flow Physiology Family. J Neurosurg Anesthesiol. 2020 Apr;32(2):93-94. doi: 10.1097/ANA.0000000000000677. No abstract available.
- Background: PubMed 23616589ter Laan M, van Dijk JM, Elting JW, Staal MJ, Absalom AR. Sympathetic regulation of cerebral blood flow in humans: a review. Br J Anaesth. 2013 Sep;111(3):361-7. doi: 10.1093/bja/aet122. Epub 2013 Apr 24.
- Background: PubMed 153Fitch W, MacKenzie ET, Harper AM. Effects of decreasing arterial blood pressure on cerebral blood flow in the baboon. Influence of the sympathetic nervous system. Circ Res. 1975 Nov;37(5):550-7. doi: 10.1161/01.res.37.5.550.
- Background: PubMed 560150Seltzer JL. Hoarseness and Horner's syndrome after interscalene brachial plexus block. Anesth Analg. 1977 Jul-Aug;56(4):585-6. doi: 10.1213/00000539-197707000-00033. No abstract available.
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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.
Anna Maria Bombardieri, MD, PhD principal investigator
Stanford University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Regional Anesthesia and Horner Syndrome, run by Stanford University at 1 site in United States.
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 3 inclusion and 2 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: stopped early, as of the sponsor's last update on 16 Sep 2021. 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 United States. 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 was stopped early (reason given: Study not properly designed for outcome measure). Results are not available in the source record.
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?
Cerebral Blood Flow Velocity before and after interscalene nerve block (time frame: baseline, after 30 minutes). 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 NCT04642612, which also lists 5 linked publications.
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 16 Sep 2021.