Intraoperative AwarenessNCT01377636
Measurement of Bispectral Index and Awareness in Patients Undergoing Electrophysiology Studies With Isoproterenol
A study testing Isoproterenol in people with Intraoperative Awareness, run by NYU Langone Health at 1 site in United States.
Trial summary
Isoproterenol is used as a cardiac stimulant in electrophysiology studies (EP). Preliminary data suggests that administration of isoproterenol increases the Bispectral index (BIS). BIS is used to monitor neuronal signals under anesthesia. The BIS level is suggested to correspond to the level of consciousness. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Intraoperative Awareness
- What is being tested?
- Isoproterenol
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 20 participants
- Where
- 1 siteUnited States
- Study dates
- Aug 2009to Oct 2011
- Phase
- Interventional
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
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 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Patients scheduled for EP studies for catheter ablation of atrial fibrillation under general anesthesia will participate in the study
Who cannot join
- Patients with neuromuscular disease precluding the use of succinylcholine will be excluded.
- Patient or cardiologist refusal
Trial locations and contacts
1 site in 1 country.
United States1 site
NYU Langone Medical Center, Department of Anesthesiology
New York, New York, 10016
About this study
Official title: Study to Measure BIS and Awareness in Patients Receiving Isoproterenol During Catheter Ablation for Atrial Fibrillation
Isoproterenol is used as a cardiac stimulant in electrophysiology studies (EP). Preliminary data suggests that administration of isoproterenol increases the Bispectral index (BIS). BIS is used to monitor neuronal signals under anesthesia. The BIS level is suggested to correspond to the level of consciousness. We hypothesize that isoproterenol increases BIS values because it increases the patient's level of consciousness through its central nervous system (CNS) stimulatory effects. In this study, we will administer increasing doses of isoproterenol to EPS patients. We will measure the BIS levels continuously before and after isoproterenol administration. In addition, we will test the level of awareness of patients by their response to a modified isolated forearm technique.
Read the detailed description
Isoproterenol is a direct acting Beta-1 and Beta-2 agonist useful for its effects on bronchodilation and myocardial contractility. Its CNS side effects include nervousness, headache, dizziness, restlessness, insomnia, anxiety, tension, blurring of vision, fear, and excitement. In addition to our preliminary data, two case reports show an increase in BIS with administration of isoproterenol. Our hypothesis is that administration of isoproterenol will increase the level of consciousness of the patient as reflected in the BIS reading.
The BIS Vista Monitor is a non-invasive device that measures the electrical activity of the brain. It computes a number between 0 and 100 which corresponds to a level of consciousness which is known as the Bispectral (BIS) value. Using the BIS value to guide administration of anesthetic medication, clinicians can make informed decisions for optimal anesthesia. This technology has the potential to prevent over sedation, but is currently not a standard monitoring device.
Another approach to evaluating the level of consciousness of anesthetized patients is to assess their ability to form memories or recall events which occurred while under anesthesia. Conscious recall is the first to disappear with decreasing levels of consciousness. A BIS of 60 or less has been shown in various studies to be sufficient to prevent conscious recall in the vast majority of patients. We propose to use a modified isolated forearm technique test in which the patient is asked to squeeze an observer's hand during anesthesia to ascertain if awareness can occur without recall at a BIS of 60 to 70. (6) Implicit memory in which there is no conscious recall or evaluation of awareness can be assessed by word stem completion tests and has been shown to occur with a BIS as low as 40 - 60 although these results are not consistent across all studies. (7)
- Conditions
- Intraoperative Awareness
- Being tested
- Isoproterenol
- Keywords
- Isoproterenol, Bispectral index (BIS), electrophysiology studies (EPS)
- Medical subject headings
- Intraoperative Awareness
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
IsoproterenolDrug
Also called isoprenaline
patients will receive isoproterenol, have a BIS monitoring device and a modified isolated forearm test (no neuromuscular blockade).
| Study group | Role | What they receive |
|---|---|---|
| Isoproterenol, BIS, forearm test | Experimental | 30 consecutive patients scheduled for EP studies under general anesthesia will participate in the study. Patients with neuromuscular disease precluding the use of succinylcholine will be excluded. The only other exclusions will be patient or cardiologist refusal. No attempts will be made to alter concurrent patient medication. Receives: Drug: Isoproterenol |
What is being measured
The primary outcome is the main question the study is designed to answer.
Number of Participants With an Increase in BIS Readings During Steady State
Increasing doses of isoproterenol (5,10,15,20 mcg/minute) were administered to patients undergoing catheter ablation for atrial fibrillation. BIS levels were measured continuously before and after isoproterenol administration. Number of participants with increase in BIS reading during anesthetic steady state are reported below. The BIS scale ranges from 0 to 100. The individual's baseline BIS was measured continuously and was maintained in an anesthetic steady state with minimum variance prior to isoproterenol. A deviation from the mean in excess of 3 points (2 STD) was defined categorically as a positive response and was counted dichotomously.
Measured: During time of Electrophysiology (EP) studies.
BIS Change
The BIS scale ranges from 0 to 100. The individual's baseline BIS was measured continuously and was maintained in an anesthetic steady state with minimum variance prior to isoproterenol. A deviation from the mean in excess of 3 points (2 STD) was defined categorically as a positive response and was counted dichotomously.The difference between Pre-BIS and Post-BIS was calculated.
Measured: Within 20 minutes of starting isoproterenol infusion
Secondary outcomes (2)
Number of Participants With Spontaneous Musculoskeletal Movement
Increasing doses of isoproterenol (5,10,15,20 mcg/minute) were administered to patients undergoing catheter ablation for atrial fibrillation. Patients under steady state total venous anesthesia (TIVA) with propofol and remifentanil infusions with BIS around 50 normally do not move even in the absence of neuromuscular blockade. Spontaneous movement appearing like restlessness during sleep is unusual. Several patients under anesthesia after isoproterenol appear to wake up and move spontaneously.
Measured: Within 20 minutes of starting isoproterenol infusion
Number of Participants Who Follow Verbal Command to Squeeze Hands
Increasing doses of isoproterenol (5,10,15,20 mcg/minute) were administered to patients undergoing catheter ablation for atrial fibrillation. Ability to follow verbal commands before and after isoproterenol infusion was assessed by asking subjects to "squeeze my hands".
Measured: Within 20 minutes of starting isoproterenol infusion
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted21 Jun 2011 (estimated)
- Study startAug 2009
- Primary completionSep 2011
- Study completionOct 2011
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Intraoperative AwarenessStudies of the same condition, open and under way.
- More trials run by NYU Langone HealthThe 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
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 20 participants (actual)
Sponsor and investigators
- Lead sponsor
- NYU Langone Health
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Patrick Linton, MD, Principal investigator, NYU School of Medicine
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT01377636
- Sponsor's protocol ID
- H#: 09-0440
- Status last verified
- Feb 2015
- First submitted
- 22 Mar 2010
- Last updated
- 23 Feb 2015
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- No
Publications
O'Neill DK, Aizer A, Linton P, Bloom M, Rose E, Chinitz L. Isoproterenol infusion increases level of consciousness during catheter ablation of atrial fibrillation. J Interv Card Electrophysiol. 2012 Aug;34(2):137-42. doi: 10.1007/s10840-011-9652-3. Epub 2012 Feb 25.
PubMed 22366997
Study at a glance
From the registry record, last updated by the sponsor on 23 Feb 2015. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Study to Measure BIS and Awareness in Patients Receiving Isoproterenol During Catheter Ablation for Atrial Fibrillation
- ClinicalTrials.gov ID
- NCT01377636
- Acronym / sponsor ID
- H#: 09-0440
- Conditions
- Intraoperative Awareness
- Keywords
- Isoproterenol, Bispectral index (BIS), electrophysiology studies (EPS)
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 20 participants (actual)
- Lead sponsor
- NYU Langone HealthUniversity, hospital or other
- Study start
- Aug 2009
- Primary completion
- Sep 2011 (actual)
- Study completion
- Oct 2011 (actual)
- First posted
- 21 Jun 2011 (estimated)
- Results
- Posted 23 Feb 2015
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Isoproterenol is used as a cardiac stimulant in electrophysiology studies (EP). Preliminary data suggests that administration of isoproterenol increases the Bispectral index (BIS). BIS is used to monitor neuronal signals under anesthesia. The BIS level is suggested to correspond to the level of consciousness. We hypothesize that isoproterenol increases BIS values because it increases the patient's level of consciousness through its central nervous system (CNS) stimulatory effects. In this study, we will administer increasing doses of isoproterenol to EPS patients. We will measure the BIS levels continuously before and after isoproterenol administration. In addition, we will test the level of awareness of patients by their response to a modified isolated forearm technique.
Detailed description
Isoproterenol is a direct acting Beta-1 and Beta-2 agonist useful for its effects on bronchodilation and myocardial contractility. Its CNS side effects include nervousness, headache, dizziness, restlessness, insomnia, anxiety, tension, blurring of vision, fear, and excitement. In addition to our preliminary data, two case reports show an increase in BIS with administration of isoproterenol. Our hypothesis is that administration of isoproterenol will increase the level of consciousness of the patient as reflected in the BIS reading.
The BIS Vista Monitor is a non-invasive device that measures the electrical activity of the brain. It computes a number between 0 and 100 which corresponds to a level of consciousness which is known as the Bispectral (BIS) value. Using the BIS value to guide administration of anesthetic medication, clinicians can make informed decisions for optimal anesthesia. This technology has the potential to prevent over sedation, but is currently not a standard monitoring device.
Another approach to evaluating the level of consciousness of anesthetized patients is to assess their ability to form memories or recall events which occurred while under anesthesia. Conscious recall is the first to disappear with decreasing levels of consciousness. A BIS of 60 or less has been shown in various studies to be sufficient to prevent conscious recall in the vast majority of patients. We propose to use a modified isolated forearm technique test in which the patient is asked to squeeze an observer's hand during anesthesia to ascertain if awareness can occur without recall at a BIS of 60 to 70. (6) Implicit memory in which there is no conscious recall or evaluation of awareness can be assessed by word stem completion tests and has been shown to occur with a BIS as low as 40 - 60 although these results are not consistent across all studies. (7)
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Isoproterenol, BIS, forearm test | Experimental | Drug: Isoproterenol30 consecutive patients scheduled for EP studies under general anesthesia will participate in the study. Patients with neuromuscular disease precluding the use of succinylcholine will be excluded. The only other exclusions will be patient or cardiologist refusal. No attempts will be made to alter concurrent patient medication. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (1 listed)
- Patients scheduled for EP studies for catheter ablation of atrial fibrillation under general anesthesia will participate in the study
Key exclusion criteria (2 listed)
- Patients with neuromuscular disease precluding the use of succinylcholine will be excluded.
- Patient or cardiologist refusal
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 |
|---|---|---|
| IsoproterenolAlso: isoprenalinepatients will receive isoproterenol, have a BIS monitoring device and a modified isolated forearm test (no neuromuscular blockade). | Drug | Isoproterenol, BIS, forearm test |
Primary outcome
Number of Participants With an Increase in BIS Readings During Steady State
Time frame: During time of Electrophysiology (EP) studies.
Increasing doses of isoproterenol (5,10,15,20 mcg/minute) were administered to patients undergoing catheter ablation for atrial fibrillation. BIS levels were measured continuously before and after isoproterenol administration. Number of participants with increase in BIS reading during anesthetic steady state are reported below. The BIS scale ranges from 0 to 100. The individual's baseline BIS was measured continuously and was maintained in an anesthetic steady state with minimum variance prior to isoproterenol. A deviation from the mean in excess of 3 points (2 STD) was defined categorically as a positive response and was counted dichotomously.
BIS Change
Time frame: Within 20 minutes of starting isoproterenol infusion
The BIS scale ranges from 0 to 100. The individual's baseline BIS was measured continuously and was maintained in an anesthetic steady state with minimum variance prior to isoproterenol. A deviation from the mean in excess of 3 points (2 STD) was defined categorically as a positive response and was counted dichotomously.The difference between Pre-BIS and Post-BIS was calculated.
2 secondary outcomes
Number of Participants With Spontaneous Musculoskeletal Movement
Time frame: Within 20 minutes of starting isoproterenol infusion
Number of Participants Who Follow Verbal Command to Squeeze Hands
Time frame: Within 20 minutes of starting isoproterenol infusion
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 23 Feb 2015.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- Background: PubMed 22366997O'Neill DK, Aizer A, Linton P, Bloom M, Rose E, Chinitz L. Isoproterenol infusion increases level of consciousness during catheter ablation of atrial fibrillation. J Interv Card Electrophysiol. 2012 Aug;34(2):137-42. doi: 10.1007/s10840-011-9652-3. Epub 2012 Feb 25.
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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.
Patrick Linton, MD principal investigator
NYU School of Medicine
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Isoproterenol in people with Intraoperative Awareness, run by NYU Langone Health 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 1 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: finished, as of the sponsor's last update on 23 Feb 2015. 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?
Yes. Results are posted in the registry (first posted 23 Feb 2015). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
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?
Number of Participants With an Increase in BIS Readings During Steady State (time frame: During time of Electrophysiology (EP) studies.). 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?
On the ClinicalTrials.gov record for NCT01377636, 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 23 Feb 2015.