EEG-based Depth of Anesthesia-monitoring, Effects on Dosage and Cognition

November 3, 2023 updated by: Luis George Romundstad, Oslo University Hospital

EEG-based Depth of Anesthesia-monitoring During General Anesthesia - Effects on Time to Wake-up and Post-operative Cognition

Depth of anesthesia-monitoring based on EEG changes demands knowledge about the effects of the different anesthetic medications on EEG waveforms. The investigators want to investigate the use of the raw-EEG waveform in addition to indexes (BIS) and EEG spectrogram analyses for depth of anesthesia monitoring. The investigators hypothesize that with the use of this monitoring, anaesthesia providers will be able to better individualize the dosage of anesthetic drugs, and that this will reduce the total consumption of anesthetic medication , thus reducing time to wake-up after surgery. Some studies have indicated that too deep anesthesia, confirmed by "burst-suppression" or isoelectric-EEG , is associated with increased postoperative cognitive dysfunction (POCD). The investigators will therefore assess the patients with the Cambridge Neuropsychological Test Automated Battery tests in mild cognitive impairment (CANTAB-MCI) cognitive function assessment tool.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

It has been over 80 years since Gibbs et al showed how the electroencephalogram (EEG) systematically changed in concurrence with increasing doses of hypnotic drugs such as penthobarbital and Ether. The study concluded that "Electroencephalography may therefore be of value in controlling depth of anesthesia and sedation". In spite of a solid documentation of the systematic connection between dosing of anesthetic drugs, EEG-patterns and level of sedation/anesthesia , EEG-based DoA has not become a part of standard of care in anesthetic management. There is abundant evidence of how different anesthetic drugs leads to characteristic fluctuations in human brain electrical activity, relating to depth of anesthesia, anesthetic drug of choice, and age . These anesthetic induced fluctuations are readily visible as changes in the patients EEG.

Anesthetic drugs are usually administered in pharmacological models based on a population taking into account their age, weight and height. However, there is a significant difference in how patients respond to these models. In adults there is evidence that the doses needed to achieve consciousness varies with a factor of 2 above and below suggested doses. In under-dosing of anesthetics there is a risk of peroperative awareness . On the other hand there is also evidence that overdosing of anesthetics has harmful effects; children receiving more than 4% Sevoflurane can demonstrate epileptiform activity , and adults overdosing into "burst suppression" during anesthesia has a higher risk of postoperative delirium (POD) and increased occurrence of postoperative cognitive dysfunction (POCD) .

Bispectral Index (BIS) is an algorithm developed by Aspect Medical Systems in 1994, which is based on weighted sums of EEG subparameters to present an index from 0 to 100 for depth of anesthesia, where 100 is wide awake, and 0 is an isoelectric EEG. The BIS target for a deep enough anesthesia is set to be between 40 and 60. The BIS number is often in concurrence with other clinical observations related to anesthetic depth, however there is also an experience of divergence. BIS and other EEG-based indices are programmed from adult cohorts, and cannot be directly trusted in children, or the elderly . There is also an incapability in these preprogrammed indices (BIS and other) to integrate how specific anesthetic drugs affect the EEG, and thenceforth the BIS value. An example of this is how the drug Ketamine induces a specific gamma-frequency in the EEG, which the BIS-index translate as a lighter anesthesia, even though the drug is administered "on top of" an already deep level of anesthesia.

Study Type

Interventional

Enrollment (Estimated)

100

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

  • Name: Anders Aasheim, Master
  • Phone Number: +4748129280
  • Email: uxanim@ous-hf.no

Study Contact Backup

Study Locations

  • Norway
      • Oslo, Norway, 0124
        • Recruiting
        • Oslo University Hospital

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years to 85 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria

.

Participants are eligible to be included in the study only if all of the following criteria apply:

Age

  1. Participant must be above the age of 18 years , at the time of signing the informed consent.

    Sex

  2. Male and/or female

    Informed Consent

  3. Capable of giving signed informed consent as described in protocol which includes compliance with the requirements and restrictions listed in the informed consent form (ICF) and in the protocol

    Exclusion Criteria

    Participants are excluded from the study if any of the following criteria apply:

  4. Psychiatric disorders
  5. Pregnancy
  6. Breast feeding
  7. Using antiepileptic drugs.
  8. Central neurological disease
  9. Unable to complete baseline CANTAB-test.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Other
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Triple

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Visual EEG
Individual dosing of anesthetic medications based on EEG AND other standardized clinical observations (BP, HR)
Device: Bilateral Bispectral Index and EEG
raw-EEG and spectrographic EEG-visualization based on the Medtronic Device "Bilateral BiSpectral Index"
Experimental: Blinded EEG
Individual dosing of anesthetic medications based on standardized clinical observations (BP, HR).
Device: Bilateral Bispectral Index and EEG
raw-EEG and spectrographic EEG-visualization based on the Medtronic Device "Bilateral BiSpectral Index"

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
EEG-based Depth of anesthesia-monitoring and dosage of anesthetic medications
Time Frame: 24 hours
Summarizing the total amount of anesthetic drugs used, mg/kg/hr
24 hours
EEG-based Depth of anesthesia-monitoring and dosage of vasopressor medications during anesthesia
Time Frame: 24 hours
Summarizing the total amount of vasopressor drugs used, micg/kg/min
24 hours
EEG-based Depth of anesthesia-monitoring and time to wake-up after surgery
Time Frame: 24 hours
Time from the end of intravenous infusion of anesthetic - to motoric and verbal response.
24 hours
Evaluation of cognitive function using CANTAB-MCI
Time Frame: 1 day preoperatively to 24 hours after wake-up
Baseline assessment 1 day preoperatively, assessment 2-3 hours after wake-up, and 24 hours after wake-up using CANTAB-MCI
1 day preoperatively to 24 hours after wake-up

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Oslo University Hospital

Investigators

  • Principal Investigator: Luis G Romundstad, MD, PhD, Oslo University Hospital

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

January 8, 2021

Primary Completion (Estimated)

March 15, 2025

Study Completion (Estimated)

December 20, 2025

Study Registration Dates

First Submitted

March 13, 2020

First Submitted That Met QC Criteria

August 25, 2020

First Posted (Actual)

August 27, 2020

Study Record Updates

Last Update Posted (Actual)

November 7, 2023

Last Update Submitted That Met QC Criteria

November 3, 2023

Last Verified

November 1, 2023

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 2019/32173

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

Data storage and management will follow GCP and GDPR requirements. Data sharing after end of study will follow the current data sharing policy at Oslo University Hospital. Data set can be made available for journal peer review process.

IPD Sharing Time Frame

After end of study, 2025, and 5 years.

IPD Sharing Access Criteria

Access through application to study contactpersons.

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • SAP
  • ICF
  • ANALYTIC_CODE
  • CSR

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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