Evidence map›Paper›PMID 26174300›Full record

ArticleBritish journal of anaesthesia2015

The Ageing Brain: Age-dependent changes in the electroencephalogram during propofol and sevoflurane general anaesthesia.

P L Purdon, K J Pavone, O Akeju, A C Smith, A L Sampson, J Lee, D W Zhou, K Solt, E N Brown

6 registry-linked trialsAbstract read
PubMed Full text at PMC Publisher
In one paragraph

Article in British journal of anaesthesia, 2015. The graph could read no effect estimate from its abstract, so it casts no vote on the map. It is linked to 6 registered trials, which are not on this map. Cited by 170 papers, 2 of them syntheses that pooled it.

0numbers the graph read from it
0cells of the map it votes in
170citing papers in PubMed, 2 pooled it
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

NCT03442179 unknown statusnot on this mapstarted 2019, after this paper: background citation

Cognitive Outcomes and Neuroimages Associated With Anesthesia-Related EEG Signatures

TypeobservationalSponsorMassachusetts General HospitalRan2019 to 2024Enrolled24ConditionsElderly, General Anesthesia
NCT04189861 completednot on this mapstarted 2020, after this paper: background citation

The Role of Brain Wave Monitoring in Reducing the Incidence of Postoperative Cognitive Dysfunction

TypeobservationalSponsorDartmouth-Hitchcock Medical CenterRan2020 to 2025Enrolled31ConditionsPostoperative Cognitive Dysfunction
NCT04774120 completednot on this mapstarted 2020, after this paper: background citation

Relationship Between Bispectral Index, EEG Features, and Propofol Effect-site Concentration in Young and Elderly Patients.

TypeobservationalSponsorPontificia Universidad Catolica de ChileRan2020 to 2021Enrolled30ConditionsElectroencephalography, Aging, Propofol, Depth of AnesthesiaArmsPropofol
NCT04783662 completednot on this mapstarted 2021, after this paper: background citation

Study of an Intraoperative Frontal Electroencephalographic Marker of Preoperative Frailty in Patients Over 65 Years of Age for Elective Non-cardiac Surgery.

TypeobservationalSponsorPontificia Universidad Catolica de ChileRan2021 to 2022Enrolled60ConditionsFrailtyArmsIntraoperative frontal electroencephalogram
NCT05790720 narecruitingnot on this mapstarted 2024, after this paper: background citation

Development of a Pharmacodynamic Model for Propofol in Older Adults (Development phaRmacodynamic mOdel Propofol oLdEr adulTs: DROPLET)

TypeinterventionalSponsorPontificia Universidad Catolica de ChileRan2024 to 2026Enrolled36ConditionsAgedArmsPropofol
NCT06667869 recruitingnot on this mapstarted 2025, after this paper: background citation

Sistema de monitorización multiparámetros Para sedación de Pacientes críticos en UCI (ROMANTIC: multipaRameter mOnitoring systeM for sedAtion iNThe ICu)

Typeobservational_patient_registrySponsorPontificia Universidad Catolica de ChileRan2025 to 2026Enrolled80ConditionsSedation ComplicationArmsSedative
3 · Its place in the literature

Who cites it

170 citing papers in PubMed, 2 syntheses or guidelines pooled it.

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110 more citing papers are in PubMed but not listed here.

4 · The record

Corrections and comments

5 · Who and what money

Authors and funding

9 authors.

P L PurdonDepartment of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA, USA Harvard Medical School, Boston, MA, USA Department of Brain and Cognitive Science patrickp@nmr.mgh.harvard.edu enb@neurostat.mit.edu.
K J PavoneDepartment of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA, USA.
O AkejuDepartment of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA, USA Harvard Medical School, Boston, MA, USA.
A C SmithDepartment of Brain and Cognitive Science.
A L SampsonDepartment of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA, USA.
J LeeHarvard-Massachusetts Institute of Technology Division of Health Sciences and Technology.
D W ZhouDepartment of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA, USA.
K SoltDepartment of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA, USA Harvard Medical School, Boston, MA, USA.
E N BrownDepartment of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA, USA Harvard Medical School, Boston, MA, USA Department of Brain and Cognitive Science Harvard-Massachusetts Institute of Technology Division of Health Sciences and Technology Institute for Medical Engineering and Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA patrickp@nmr.mgh.harvard.edu enb@neurostat.mit.edu.

Funding

A Neural Systems Approach to Monitoring and Drug-Delivery for General AnesthesiaDP2OD006454 · OD · MASSACHUSETTS GENERAL HOSPITAL · PI PURDON, PATRICK L. · 2009 to 2009
$2.7M
NIH HHS DP2-OD006454
6 · The paper itself

Abstract

backgroundAnaesthetic drugs act at sites within the brain that undergo profound changes during typical ageing. We postulated that anaesthesia-induced brain dynamics observed in the EEG change with age.

methodsWe analysed the EEG in 155 patients aged 18-90 yr who received propofol (n=60) or sevoflurane (n=95) as the primary anaesthetic. The EEG spectrum and coherence were estimated throughout a 2 min period of stable anaesthetic maintenance. Age-related effects were characterized by analysing power and coherence as a function of age using linear regression and by comparing the power spectrum and coherence in young (18- to 38-yr-old) and elderly (70- to 90-yr-old) patients.

resultsPower across all frequency bands decreased significantly with age for both propofol and sevoflurane; elderly patients showed EEG oscillations ∼2- to 3-fold smaller in amplitude than younger adults. The qualitative form of the EEG appeared similar regardless of age, showing prominent alpha (8-12 Hz) and slow (0.1-1 Hz) oscillations. However, alpha band dynamics showed specific age-related changes. In elderly compared with young patients, alpha power decreased more than slow power, and alpha coherence and peak frequency were significantly lower. Older patients were more likely to experience burst suppression.

conclusionsThese profound age-related changes in the EEG are consistent with known neurobiological and neuroanatomical changes that occur during typical ageing. Commercial EEG-based depth-of-anaesthesia indices do not account for age and are therefore likely to be inaccurate in elderly patients. In contrast, monitoring the unprocessed EEG and its spectrogram can account for age and individual patient characteristics.

Indexed as

Anesthesia, GeneralAdolescentAdultAgedAged, 80 and overAgingAnestheticsElectroencephalographyFemaleHumansMaleMethyl EthersMiddle AgedPropofolSevofluraneYoung AdultAnestheticsMethyl EthersPropofolSevofluraneageingbrain monitoringEEGelderlyelectroencephalographypropofolsevoflurane

Identifiers

PMID26174300
PMCPMC4501918

What OpenQuestion holds

Textmetadata
Read underepoch 390

Registered trials

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.