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ElderlyNCT03442179

Cognitive Outcomes and Neuroimages Associated With Anesthesia-Related EEG Signatures

An observational study of Elderly and General Anesthesia, run by Massachusetts General Hospital at 1 site in United States.

Unknown status

Status not confirmed. The sponsor has not verified this record for over two years, so it may be out of date.

Official record
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Trial summary

In this study, we propose to evaluate the relationship between the alpha oscillation dynamics and the signals derived from the brain images related to brain aging. Read more about this study

Who is it for?
Ages 65 years and older
Conditions the study is for
Elderly, General Anesthesia
How many people
24 participants
Where
1 siteUnited States
Study dates
13 Feb 2019to 11 May 2024
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 65 years and older
  • All sexes
  • No healthy volunteers
  • Older adult

Study population: 45 subjects (male and female) aged 65 and above scheduled for open or laparoscopic general surgical procedures under general anesthesia

Who may be able to join

  • 65 years old or above (male and female)
  • American Society of Anesthesiologists (ASA) physical status classification of I, II or III.
  • Candidates scheduled for open or laparoscopic general surgical procedures under general anesthesia
  • No cognitive impairment base on Telephone Interview for Cognitive Status (TICS)
  • Fluency in English Language

Who cannot join

  • Prior diagnosis of dementia
  • Prior diagnosis of Alzheimer's Disease
  • Prior history of psychiatric or neurological diseases including:
  • Schizophrenia
  • Parkinsonism
  • Epilepsy or seizure
Show all 18Show fewer
  • Brain injury
  • Brain tumors/metastases
  • Encephalitis
  • Stroke, CVA, TIA
  • Drug or alcohol abuse:
  • Any history of IV drug abuse
  • Alcohol/drug (non-IV) abuse <10 years
  • Language impairment
  • Hearing or visual impairment
  • Severe obesity (BMI ≥40 kg/m2)
  • MRI contraindications, such as presence of pacemakers, aneurysm clips, artificial heart valves, ear implants, metal fragments, or foreign objects in the eyes, skin, or body
  • Body weight of > 300 lbs. (weight limit of the MRI table)

Trial locations and contacts

1 site in 1 country.

United States1 site
  • Massachusetts General Hospital

    Boston, Massachusetts, 02114

Other trials in United States

About this study

In this study, we propose to evaluate the relationship between the alpha oscillation dynamics and the signals derived from the brain images related to brain aging.

Read the detailed description

In 1955 Bedford reported the "adverse cerebral effects of anesthesia on old people" and suggested precautions in relation to operations on the elderly. Since then, many studies have investigated the incidence of and the risk factors for postoperative cognitive dysfunction (POCD). The incidence ranges from 8.9% to 46.1% and advanced age, preoperative mild cognitive impairment, extensive surgical procedures and other factors have been identified as important risk factors. The incidence has been reported to be as high as 41.4% at hospital discharge and 12.7% at 3 months after surgery in the elderly (60 years or older). Postoperative delirium (POD) is a more acute complication of major surgery, affecting 10-70% of surgical patients 60 years and older. Some studies have shown the association between POD and early POCD, and even POD and POCD are commonly reported as being part of the same continuum. Whether this is true or not, both represent postoperative cognitive deterioration, and age is the predominant risk factor for both.

Every day in the United States, nearly 100,000 patients undergo general anesthesia and sedation for surgical and diagnostic procedures. Approximately 35% of all surgical procedures are performed on adults older than 65 years. Considering the aging surgical population, the burden of postoperative cognitive disorders will almost certainly increase over time.

Although many factors, such as surgical stress, inflammation, and other comorbidities may contribute to POCD, there is evidence that anesthetic exposure plays a major role. Pre-clinical studies have demonstrated that exposure to anesthetic drugs is neurotoxic, and that older animals are particularly vulnerable. It is also generally understood that the elderly are more sensitive to anesthetics, meaning that lower doses of anesthetic drugs are required to induce and maintain unconsciousness. This has led to age-adjusted guidelines for anesthetic dosing, which in theory could be used to mitigate potentially harmful anesthetic exposures. However, these guidelines describe the age-dependent dose-response relationships for a population of patients; individual drug requirements can vary significantly, by a factor of ~2 above or below the levels recommended by population-based models. In the absence of a means to measure and monitor individual drug responses, anesthesiologists would tend to err on the side of administering more anesthetic than required, to minimize the probability of patient awareness across the population as a whole.

Fortunately, in recent years, significant progress has been made to understand the neural mechanisms of anesthesia-induced unconsciousness, making it possible to monitor individual patients' drug responses using the electroencephalogram (EEG). Increasing concentrations of the commonly-used GABAergic anesthetic drugs, such as propofol and sevoflurane, induce a stereotyped sequence of brain oscillations with increasing drug concentration. These brain oscillations are directly related to the states of sedation and unconsciousness induced by anesthetic drugs, and readily observed using the EEG. At lower concentrations, propofol and sevoflurane, two of the most commonly used anesthetic drugs, induce beta oscillations (12-25 Hz). At concentrations producing unconsciousness for general anesthesia, these drugs produce frontal alpha (8-12 Hz) and slow (0.1 to 1 Hz) oscillations. At still higher concentrations, propofol and sevoflurane produce a pattern referred to as burst suppression, a deep state of brain inactivation in which brain activity is punctuated by long periods of neuronal and EEG silence. However, it is now known that elderly patients do not always exhibit this canonical EEG signature under general anesthesia. First, it was described that ageing was associated with a decrease in the frontal alpha power. Then, other studies suggested that older patients with poor preoperative cognitive performance also lack the alpha band under anesthesia. And finally, our group demonstrated that a low alpha power is also associated with a higher risk to develop burst suppression under anesthesia. Nonetheless, the potential mechanism related to the lower alpha power with ageing and cognitive function remains unknown. In this study, we propose to evaluate the relationship between the alpha oscillation dynamics and the signals derived from brain images related to brain aging.

We hypothesize that: 1) Brain imaging signals will correlate with the alpha power induced by anesthetics, and 2) Aging brain imaging features will be associated with postoperative cognitive recovery.

Keywords
Aging, Anesthesia, EEG monitoring, Burst suppression

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Postoperative Delirium Incidence

    postoperative delirium will be assessed using 3-Minute Diagnostic Interview for Confusion Assessment Method (CAM)

    Measured: on postoperative day 1

  2. Postoperative Cognitive Decline

    postoperative cognitive dysfunction will be assessed using the Montreal Cognitive Assessment (MoCA)

    Measured: one week before the surgery and postoperative day 7

  3. Intraoperative Burst Suppression Time

    we will use the EEG data recorded during the surgical procedure to calculate time spent in burst suppression

    Measured: during the surgical procedure under general anesthesia

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted22 Feb 2018
  2. Study start13 Feb 2019
  3. Primary completion11 May 2023
  4. Study completion11 May 2024 (estimated)

Resources

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
24 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT03442179
Sponsor's protocol ID
2017P000413
Status last verified
Jul 2023
First submitted
14 Feb 2018
Last updated
1 Aug 2023
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
Undecided

Publications

  • Akeju O, Westover MB, Pavone KJ, Sampson AL, Hartnack KE, Brown EN, Purdon PL. Effects of sevoflurane and propofol on frontal electroencephalogram power and coherence. Anesthesiology. 2014 Nov;121(5):990-8. doi: 10.1097/ALN.0000000000000436.

    PubMed 25233374
  • Fournier A, Krause R, Winterer G, Schneider R. Biomarkers of postoperative delirium and cognitive dysfunction. Front Aging Neurosci. 2015 Jun 9;7:112. doi: 10.3389/fnagi.2015.00112. eCollection 2015.

    PubMed 26106326
  • Avidan MS, Fritz BA, Maybrier HR, Muench MR, Escallier KE, Chen Y, Ben Abdallah A, Veselis RA, Hudetz JA, Pagel PS, Noh G, Pryor K, Kaiser H, Arya VK, Pong R, Jacobsohn E, Grocott HP, Choi S, Downey RJ, Inouye SK, Mashour GA. The Prevention of Delirium and Complications Associated with Surgical Treatments (PODCAST) study: protocol for an international multicentre randomised controlled trial. BMJ Open. 2014 Sep 17;4(9):e005651. doi: 10.1136/bmjopen-2014-005651.

    PubMed 25231491
  • Avidan MS, Jacobsohn E, Glick D, Burnside BA, Zhang L, Villafranca A, Karl L, Kamal S, Torres B, O'Connor M, Evers AS, Gradwohl S, Lin N, Palanca BJ, Mashour GA; BAG-RECALL Research Group. Prevention of intraoperative awareness in a high-risk surgical population. N Engl J Med. 2011 Aug 18;365(7):591-600. doi: 10.1056/NEJMoa1100403.

    PubMed 21848460
  • BEDFORD PD. Adverse cerebral effects of anaesthesia on old people. Lancet. 1955 Aug 6;269(6884):259-63. doi: 10.1016/s0140-6736(55)92689-1. No abstract available.

    PubMed 13243706
  • Bennett C, Voss LJ, Barnard JP, Sleigh JW. Practical use of the raw electroencephalogram waveform during general anesthesia: the art and science. Anesth Analg. 2009 Aug;109(2):539-50. doi: 10.1213/ane.0b013e3181a9fc38.

    PubMed 19608830
  • Besch G, Liu N, Samain E, Pericard C, Boichut N, Mercier M, Chazot T, Pili-Floury S. Occurrence of and risk factors for electroencephalogram burst suppression during propofol-remifentanil anaesthesia. Br J Anaesth. 2011 Nov;107(5):749-56. doi: 10.1093/bja/aer235. Epub 2011 Aug 8.

    PubMed 21828343
  • Brice DD, Hetherington RR, Utting JE. A simple study of awareness and dreaming during anaesthesia. Br J Anaesth. 1970 Jun;42(6):535-42. doi: 10.1093/bja/42.6.535. No abstract available.

    PubMed 5423844
  • Brown EN, Lydic R, Schiff ND. General anesthesia, sleep, and coma. N Engl J Med. 2010 Dec 30;363(27):2638-50. doi: 10.1056/NEJMra0808281. No abstract available.

    PubMed 21190458
  • Bruhn J, Bouillon TW, Shafer SL. Bispectral index (BIS) and burst suppression: revealing a part of the BIS algorithm. J Clin Monit Comput. 2000;16(8):593-6. doi: 10.1023/A:1012216600170.

    PubMed 12580235
  • Chan MT, Cheng BC, Lee TM, Gin T; CODA Trial Group. BIS-guided anesthesia decreases postoperative delirium and cognitive decline. J Neurosurg Anesthesiol. 2013 Jan;25(1):33-42. doi: 10.1097/ANA.0b013e3182712fba.

    PubMed 23027226
  • Chemali J, Ching S, Purdon PL, Solt K, Brown EN. Burst suppression probability algorithms: state-space methods for tracking EEG burst suppression. J Neural Eng. 2013 Oct;10(5):056017. doi: 10.1088/1741-2560/10/5/056017. Epub 2013 Sep 10.

    PubMed 24018288
  • Ching S, Cimenser A, Purdon PL, Brown EN, Kopell NJ. Thalamocortical model for a propofol-induced alpha-rhythm associated with loss of consciousness. Proc Natl Acad Sci U S A. 2010 Dec 28;107(52):22665-70. doi: 10.1073/pnas.1017069108. Epub 2010 Dec 13.

    PubMed 21149695
  • Flores FJ, Hartnack KE, Fath AB, Kim SE, Wilson MA, Brown EN, Purdon PL. Thalamocortical synchronization during induction and emergence from propofol-induced unconsciousness. Proc Natl Acad Sci U S A. 2017 Aug 8;114(32):E6660-E6668. doi: 10.1073/pnas.1700148114. Epub 2017 Jul 25.

    PubMed 28743752
  • Fritz BA, Kalarickal PL, Maybrier HR, Muench MR, Dearth D, Chen Y, Escallier KE, Ben Abdallah A, Lin N, Avidan MS. Intraoperative Electroencephalogram Suppression Predicts Postoperative Delirium. Anesth Analg. 2016 Jan;122(1):234-42. doi: 10.1213/ANE.0000000000000989.

    PubMed 26418126

Questions about this trial

What is this clinical trial studying?

An observational study of Elderly and General Anesthesia, run by Massachusetts General Hospital 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 5 inclusion and 18 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: status not confirmed, as of the sponsor's last update on 1 Aug 2023. 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?

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?

Postoperative Delirium Incidence (time frame: on postoperative day 1). The study lists 3 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 NCT03442179, which also lists 37 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 1 Aug 2023.

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