ElectroencephalographyNCT04774120
Relationship Between Bispectral Index, EEG Features, and Propofol Effect-site Concentration in Young and Elderly Patients.
An observational study of Electroencephalography and Aging, run by Pontificia Universidad Catolica de Chile at 1 site in Chile.
Trial summary
The aim of this study is to describe the BIS values and electroencephalographic patterns during total intravenous anesthesia with propofol-remifentanyl, in patients from 18 to 85 years. Read more about this study
- Who is it for?
- Ages 18 to 90 yearsHealthy volunteers can take part
- Conditions the study is for
- Electroencephalography, Aging, Propofol
- What is being tested?
- Propofol
- Type of treatment
- Injection or infusion
- How many people
- 30 participants
- Where
- 1 siteChile
- Study dates
- 11 Dec 2020to 30 May 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 90 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Study population: Elderly patients scheduled for surgery are an understudied population. Incidence of postoperative delirium and other complications can be related to changes in cerebral dynamics under anesthesia, with effects observed even after the use of anesthetics agents. Formal characterization of the dynamic relationship between propofol concentrations at the effect site (Ce), spectral power, and BIS values may provide clinically relevant information to design propofol dose schemes in young and elderly patients.
Who may be able to join
- Adult patients scheduled for elective surgery requiring general anesthesia.
- American Society of Anesthesiology (ASA) Score I or II
Who cannot join
- Patients with neurological diseases or history of cognitive impairment.
- Requiring the use of two or more drugs affecting Central nervous system
- History of drugs or alcohol abuse
- Body mass index over 35 kg/m^2
- Propofol allergy
- Cardiac congestive failure
- History of coronary syndrome
Trial locations and contacts
1 site in 1 country.
Chile1 site
Division de Anestesia - Pontificia Universidad Catolica de Chile
Santiago, Santiago Metropolitan, 8330024
About this study
The aim of this study is to describe the BIS values and electroencephalographic patterns during total intravenous anesthesia with propofol-remifentanyl, in patients from 18 to 85 years.
Read the detailed description
Propofol is an anesthetic drug regularly used in elderly patients requiring anesthesia. The electroencephalographic pattern recognized when propofol is administered is different from the pattern obtained in younger patients. Both groups present alpha and slow delta bands, but younger patients present more intense electroencephalographic bands than older patients (1). The correlation between BIS values and the power of electroencephalographic frequency bands during propofol-remifentanyl anesthesia has not been determined.
The investigators will describe the changes in BIS values and electroencephalographic patterns in young and elderly patients receiving propofol-remifentanyl anesthesia for elective surgery, at different propofol concentration levels. Formal characterization of the dynamic relationship between propofol concentrations at the effect site (Ce), spectral power, and BIS values may provide clinically relevant information to design propofol dose schemes in elderly patients.
The investigators will carry out a prospective observational clinical study at the Clinical Hospital of the Catholic University of Chile. 30 patients, aged 18-85 years, scheduled to undergo elective surgery will be recruited. Standard monitoring and 2 frontal EEG monitors will be installed: Sedline® and BIS®. The electroencephalographic signal from these monitors will be recorded simultaneously from anesthesia induction until extubation. Propofol will be started at a rate of 15-20 mg/kg/hr in patients >65 years and 20-25 mg/kg/hr in younger patients (<65 years) until a suppression rate (SR) >1% appears in the BIS® EEG monitor. If the SR is not achieved, the infusion rate can be increased by 5 mg/kg/hr every 5 minutes until 25 mg/kg/hr in the elderly group and 30 mg/kg/hr in the younger group. When the SR appears, propofol infusion will be stopped. The induction phase will be considered completed at this point. Loss of response (LOR), defined as the timepoint when patients became unresponsive to verbal commands, soft shaking, and eyelash reflex, will be assessed every 30 seconds. When patients become apneic, positive pressure mask ventilation will be started gently at a rate of 10 breaths per minute. After induction of anesthesia, opioids and neuromuscular blocking drugs will be given to facilitate tracheal intubation. When BIS values increase to recommended hypnotic levels for surgery (40-60), the propofol infusion rate will be started again at half of the induction rate. This rate will be adjusted to maintain the alpha band present in the Sedline spectrogram and SEF95 between 8-12 Hz. BIS monitor will be covered and hidden from the attending anesthesiologist during the maintenance phase. After surgery ends, EEG monitoring will continue until the patient's extubation. One hour after extubation, the Brice questionnaire will be performed to detect intraoperative awakening. Propofol concentration will be estimated using the Schnider model.
- Conditions
- Electroencephalography, Aging, Propofol, Depth of Anesthesia
- Being tested
- Propofol
- Keywords
- electroencephalography, bispectral index, propofol, alpha band, aging, burst suppression
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
PropofolDrug
Also called Diprivan, Propoven
Propofol will be started at a rate of 15-20 mg/kg/hr in patients >65 years and 20-25 mg/kg/hr in younger patients (<65 years) until a suppression rate (SR) is achieved. If not, can be increased by 5 mg/kg/hr every 5 minutes up to 25 mg/kg/hr in the elderly group and 30 mg/kg/hr in the younger group or after 15 minutes have passed. When the SR appears, propofol infusion will be stopped. Then restarted at half of the initial rate. Maintenance of anesthesia will be guided by Sedline Monitor to maintain an alpha band present in the spectrogram and SEF95 between 8-12 Hz. BIS monitor will be covered. Both EEG signals (Sedline and BIS) will be registered simultaneously until the patient's extubation.
| Study group | Role | What they receive |
|---|---|---|
| Young Patients (Patients aged 18 to 65 years.) | Propofol infusion rate will be started at 20-25 mg/kg/hr until SR achieved. Then restarted at half of the initial rate. Maintenance of anesthesia will be guided by Sedline Monitor to maintain an alpha band present in the spectrogram and SEF95 between 8-12 Hz. BIS monitor will be covered. Both EEG signals (Sedline and BIS) will be registered simultaneously until the patient's extubation. Receives: Drug: Propofol | |
| Elderly patients (Patients aged 65 to 85 years. ) | Propofol infusion rate will be started at 15-20 mg/kg/hr until SR achieved. Then restarted at half of the initial rate. Maintenance of anesthesia will be guided by Sedline Monitor to maintain an alpha band present in the spectrogram and SEF95 between 8-12 Hz. BIS monitor will be covered. Both EEG signals (Sedline and BIS) will be registered simultaneously until the patient's extubation. Receives: Drug: Propofol |
What is being measured
The primary outcome is the main question the study is designed to answer.
BIS values at which EEG patterns appears during induction of anesthesia with propofol.
BIS values correlated to specific EEG patterns (frequency bands, complexity measures and burst suppression)
Measured: From induction of anesthesia until suppression rate appears, an average of 15 minutes.
Secondary outcomes (6)
Propofol effect-site concentration (µg/ml) required to observe specific EEG patterns
Propofol effect-site concentrations achieved at the time that specific EEG patterns appear (frequency bands power, complexity measures and burst suppression).
Measured: From induction of anesthesia until loss of consciousness, an average of 15 minutes.
Propofol effect-site concentration (µg/ml) required to achieve loss of consciousness
Propofol effect-site concentration (µg/ml) at the moment of loss of consciousness
Measured: From Induction of anesthesia until suppression rate appears, an average of 15 minutes.
BIS values at loss of consciousness
BIS values at the moment of loss of consciousness
Measured: From Induction of anesthesia until suppression rate appears, an average of 15 minutes.
Percentage of time with BIS values between 40-60 and out of this range.
Percentage of time that BIS values are between 40-60 and out of this range.
Measured: From induction of anesthesia until patient's extubation, an average of 90 minutes.
Time to achieve loss of consciousness
Time (minutes) to achieve loss of consciousness.
Measured: From Induction of anesthesia until loss of consciousness, an average of 10 minutes.
Time to achieve loss suppression rate >1% in BIS monitor.
Time (minutes) to achieve loss suppression rate >1% in BIS monitor.
Measured: From Induction of anesthesia until suppression rate appears, an average of 15 minutes.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted1 Mar 2021
- Study start11 Dec 2020
- Primary completion30 Mar 2021
- Study completion30 May 2021
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 ElectroencephalographyStudies 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
- Observational
- Observational model
- Cohort
- Time perspective
- Cross-sectional
- Enrolment
- 30 participants (actual)
Sponsor and investigators
- Lead sponsor
- Pontificia Universidad Catolica de Chile
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Daniela Muñoz, MD, Principal investigator, Pontificia Universidad Catolica de Chile
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04774120
- Sponsor's protocol ID
- 200726002
- Status last verified
- Feb 2021
- First submitted
- 19 Jan 2021
- Last updated
- 16 Mar 2022
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Purdon PL, Pavone KJ, Akeju O, Smith AC, Sampson AL, Lee J, Zhou DW, Solt K, Brown EN. The Ageing Brain: Age-dependent changes in the electroencephalogram during propofol and sevoflurane general anaesthesia. Br J Anaesth. 2015 Jul;115 Suppl 1(Suppl 1):i46-i57. doi: 10.1093/bja/aev213.
PubMed 26174300
Study at a glance
From the registry record, last updated by the sponsor on 16 Mar 2022. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Relationship Between Bispectral Index, EEG Features, and Propofol Effect-site Concentration in Young and Elderly Patients.
- ClinicalTrials.gov ID
- NCT04774120
- Acronym / sponsor ID
- 200726002
- Conditions
- Electroencephalography, Aging, Propofol, Depth of Anesthesia
- Keywords
- electroencephalography, bispectral index, propofol, alpha band, aging, burst suppression
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 30 participants (actual)
- Lead sponsor
- Pontificia Universidad Catolica de ChileUniversity, hospital or other
- Study start
- 11 Dec 2020 (actual)
- Primary completion
- 30 Mar 2021 (actual)
- Study completion
- 30 May 2021 (actual)
- First posted
- 1 Mar 2021 (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 aim of this study is to describe the BIS values and electroencephalographic patterns during total intravenous anesthesia with propofol-remifentanyl, in patients from 18 to 85 years.
Detailed description
Propofol is an anesthetic drug regularly used in elderly patients requiring anesthesia. The electroencephalographic pattern recognized when propofol is administered is different from the pattern obtained in younger patients. Both groups present alpha and slow delta bands, but younger patients present more intense electroencephalographic bands than older patients (1). The correlation between BIS values and the power of electroencephalographic frequency bands during propofol-remifentanyl anesthesia has not been determined.
The investigators will describe the changes in BIS values and electroencephalographic patterns in young and elderly patients receiving propofol-remifentanyl anesthesia for elective surgery, at different propofol concentration levels. Formal characterization of the dynamic relationship between propofol concentrations at the effect site (Ce), spectral power, and BIS values may provide clinically relevant information to design propofol dose schemes in elderly patients.
The investigators will carry out a prospective observational clinical study at the Clinical Hospital of the Catholic University of Chile. 30 patients, aged 18-85 years, scheduled to undergo elective surgery will be recruited. Standard monitoring and 2 frontal EEG monitors will be installed: Sedline® and BIS®. The electroencephalographic signal from these monitors will be recorded simultaneously from anesthesia induction until extubation. Propofol will be started at a rate of 15-20 mg/kg/hr in patients >65 years and 20-25 mg/kg/hr in younger patients (<65 years) until a suppression rate (SR) >1% appears in the BIS® EEG monitor. If the SR is not achieved, the infusion rate can be increased by 5 mg/kg/hr every 5 minutes until 25 mg/kg/hr in the elderly group and 30 mg/kg/hr in the younger group. When the SR appears, propofol infusion will be stopped. The induction phase will be considered completed at this point. Loss of response (LOR), defined as the timepoint when patients became unresponsive to verbal commands, soft shaking, and eyelash reflex, will be assessed every 30 seconds. When patients become apneic, positive pressure mask ventilation will be started gently at a rate of 10 breaths per minute. After induction of anesthesia, opioids and neuromuscular blocking drugs will be given to facilitate tracheal intubation. When BIS values increase to recommended hypnotic levels for surgery (40-60), the propofol infusion rate will be started again at half of the induction rate. This rate will be adjusted to maintain the alpha band present in the Sedline spectrogram and SEF95 between 8-12 Hz. BIS monitor will be covered and hidden from the attending anesthesiologist during the maintenance phase. After surgery ends, EEG monitoring will continue until the patient's extubation. One hour after extubation, the Brice questionnaire will be performed to detect intraoperative awakening. Propofol concentration will be estimated using the Schnider model.
Study design
- Observational model
- Cohort
- Time perspective
- Cross-sectional
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Young Patients (Patients aged 18 to 65 years.) | – | Drug: PropofolPropofol infusion rate will be started at 20-25 mg/kg/hr until SR achieved. Then restarted at half of the initial rate. Maintenance of anesthesia will be guided by Sedline Monitor to maintain an alpha band present in the spectrogram and SEF95 between 8-12 Hz. BIS monitor will be covered. Both EEG signals (Sedline and BIS) will be registered simultaneously until the patient's extubation. |
| Elderly patients (Patients aged 65 to 85 years. ) | – | Drug: PropofolPropofol infusion rate will be started at 15-20 mg/kg/hr until SR achieved. Then restarted at half of the initial rate. Maintenance of anesthesia will be guided by Sedline Monitor to maintain an alpha band present in the spectrogram and SEF95 between 8-12 Hz. BIS monitor will be covered. Both EEG signals (Sedline and BIS) will be registered simultaneously until the patient's extubation. |
Who may qualify
- Ages
- 18 to 90 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
- Study population
- Elderly patients scheduled for surgery are an understudied population. Incidence of postoperative delirium and other complications can be related to changes in cerebral dynamics under anesthesia, with effects observed even after the use of anesthetics agents. Formal characterization of the dynamic relationship between propofol concentrations at the effect site (Ce), spectral power, and BIS values may provide clinically relevant information to design propofol dose schemes in young and elderly patients.
Key inclusion criteria (2 listed)
- Adult patients scheduled for elective surgery requiring general anesthesia.
- American Society of Anesthesiology (ASA) Score I or II
Key exclusion criteria (7 listed)
- Patients with neurological diseases or history of cognitive impairment.
- Requiring the use of two or more drugs affecting Central nervous system
- History of drugs or alcohol abuse
- Body mass index over 35 kg/m^2
- Propofol allergy
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 |
|---|---|---|
| PropofolAlso: Diprivan, PropovenPropofol will be started at a rate of 15-20 mg/kg/hr in patients >65 years and 20-25 mg/kg/hr in younger patients (<65 years) until a suppression rate (SR) is achieved. If not, can be increased by 5 mg/kg/hr every 5 minutes up to 25 mg/kg/hr in the elderly group and 30 mg/kg/hr in the younger group or after 15 minutes have passed. When the SR appears, propofol infusion will be stopped. Then restarted at half of the initial rate. Maintenance of anesthesia will be guided by Sedline Monitor to maintain an alpha band present in the spectrogram and SEF95 between 8-12 Hz. BIS monitor will be covered. Both EEG signals (Sedline and BIS) will be registered simultaneously until the patient's extubation. | Drug | Elderly patients (Patients aged 65 to 85 years. ), Young Patients (Patients aged 18 to 65 years.) |
Primary outcome
BIS values at which EEG patterns appears during induction of anesthesia with propofol.
Time frame: From induction of anesthesia until suppression rate appears, an average of 15 minutes.
BIS values correlated to specific EEG patterns (frequency bands, complexity measures and burst suppression)
6 secondary outcomes
Propofol effect-site concentration (µg/ml) required to observe specific EEG patterns
Time frame: From induction of anesthesia until loss of consciousness, an average of 15 minutes.
Propofol effect-site concentration (µg/ml) required to achieve loss of consciousness
Time frame: From Induction of anesthesia until suppression rate appears, an average of 15 minutes.
BIS values at loss of consciousness
Time frame: From Induction of anesthesia until suppression rate appears, an average of 15 minutes.
Percentage of time with BIS values between 40-60 and out of this range.
Time frame: From induction of anesthesia until patient's extubation, an average of 90 minutes.
Time to achieve loss of consciousness
Time frame: From Induction of anesthesia until loss of consciousness, an average of 10 minutes.
Time to achieve loss suppression rate >1% in BIS monitor.
Time frame: From Induction of anesthesia until suppression rate appears, an average of 15 minutes.
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 16 Mar 2022.
- Background: PubMed 26174300Purdon PL, Pavone KJ, Akeju O, Smith AC, Sampson AL, Lee J, Zhou DW, Solt K, Brown EN. The Ageing Brain: Age-dependent changes in the electroencephalogram during propofol and sevoflurane general anaesthesia. Br J Anaesth. 2015 Jul;115 Suppl 1(Suppl 1):i46-i57. doi: 10.1093/bja/aev213.
- Individual participant dataSharing planned: No
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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.
Daniela Muñoz, MD principal investigator
Pontificia Universidad Catolica de Chile
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 Electroencephalography and Aging, run by Pontificia Universidad Catolica de Chile at 1 site in Chile.
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 2 inclusion and 7 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 16 Mar 2022. 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 Chile. 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?
BIS values at which EEG patterns appears during induction of anesthesia with propofol. (time frame: From induction of anesthesia until suppression rate appears, an average of 15 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 NCT04774120, 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 16 Mar 2022.