Postoperative DeliriumNCT05992506
Electroencephalographic Biomarker to Predict Postoperative Delirium
An observational study of Postoperative Delirium, run by University of Chile at 2 sites in Chile.
Trial summary
Acute post-operatory cognitive dysfunction states are one of the most important complications in older patients that underwent surgery. Among them postoperative delirium (POD) is the the most studied. Read more about this study
- Who is it for?
- Ages 60 to 100 yearsHealthy volunteers can take part
- Conditions the study is for
- Postoperative Delirium
- What is being tested?
- POD risk estimation using PEUMA
- How many people
- 264 participants
- Where
- 2 sitesChile
- Study dates
- 1 Sep 2023to 30 Jun 2026
- How long will I take part?
- 30 Days
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
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 60 to 100 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Study population: Patients at risk of developing POD will be evaluated in the pre and postoperative period for cognitive dysfunction and the appearance of POD. In the intraoperative period, an EEG-based monitorization will be performed using a SedLine (Masimo, CA) Monitor.
Who may be able to join
- Age ≥ 60 years old
- Scheduled for high-risk elective surgery
- Need for at least 3 days of hospital stay after surgery
- Surgery performed under general anesthesia
- Written informed consent for participation in the trial
Who cannot join
- Patients with preoperative delirium or dementia
- Patients using neuroleptics drug during the past 6 months
- Patients with a history of encephalopathy, psychosis, stroke or brain trauma with neurologic sequels
- The use of ketamine or dexmedetomidine during surgery
- Emergency surgery
- Mechanical ventilation during the 72 after surgery
Show all 9Show fewer
- Analphabetism
- Patients who do not talk Spanish
- Patients included in another clinical trial
Trial locations and contacts
2 sites in 1 country.
Chile2 sites
Hospital Clinico Universidad de Chile
Santiago, Santiago Metropolitan, 8380456
Instituto Nacional del Cancer
Santiago, Santiago Metropolitan
About this study
Official title: Electroencephalographic Biomarker to Predict the Development of Postoperative Delirium: a Protocol of an Observational Study in a Cohort of Patients From Five Centers
Acute post-operatory cognitive dysfunction states are one of the most important complications in older patients that underwent surgery. Among them postoperative delirium (POD) is the the most studied. Patients who develop delirium have poorer long-term outcomes, such as longer length of hospital stay, institutionalization at discharge, and even higher mortality, and consequently, the human and economic costs significantly increase for the health system. Here the research team will use an observational cohort, investigator blinded in five-center with a primary endpoint to validate intraoperative EEG analysis as a reliable biomarker of postoperative delirium.
Read the detailed description
Acute post-operatory cognitive dysfunction states are one of the most frequent complications in older patients after surgery, being POD the most important. Previous studies have shown than the incidence of POD in older patients range between 10-50%. Patients who develop POD have poorer long-term outcomes, such as longer length of hospital stay, institutionalization at discharge, and even higher mortality. Consequently, the human and economic costs associated to POD represents an important issue for health systems worldwide.
A key element to diminish POD and its burden on healthcare is early diagnostic. Current risk assessment tools are centered on clinical approaches based on cognitive tests (i.e., MoCA) and/or prediction models that uses patients' clinical variables (i.e., DELPHI score). We have developed a strategy that uses intraoperative EEG features as building blocks for a new POD risk assessment predictive model. This system, called PEUMA, uses data obtained from 95 patients from a previous study (NCT04214496).
This will be a multicenter (five-centers), observational study and its primary outcome will be PEUMA's ability to predict POD.
To calculate the sample size, the methodology described by Riley et al was used. This method is specially designed for clinical prediction models. Such a tool is available online (https://mvansmeden.shinyapps.io/BeyondEPV/). The parameters used were the following:
- Number of predictor candidates: 4
- Fraction of events: 0.22. 22% was used because it is the incidence of POD in the analysis of the preliminary data of the first stage and these are in the reporting range common worldwide.
- Estimation error of the classifier: 0.06. The authors suggest prediction errors small when evaluating binary outcomes (Yes POD/No POD) The calculation indicates a sample size of 240 patients. Considering a loss of 10% (in the preliminary results of the first stage the loss was 8%), the sample size is 264 patients.
- Conditions
- Postoperative Delirium
- Being tested
- POD risk estimation using PEUMA
- Keywords
- EEG, Postoperative Delirium, Risk Assessment, Anesthesia
- Medical subject headings
- Emergence Delirium
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
POD risk estimation using PEUMADiagnostic test
A software will analyze intraoperative EEG recording for the estimation of a POD Risk Index
| Study group | Role | What they receive |
|---|---|---|
| Patients at risk of developing POD | * Patients older than 60 years
* Scheduled for elective surgery of moderate or high risk (defined as that which requires a subsequent hospitalization of at least 3 days) under general anesthesia.
* Signed informed consent. Receives: Diagnostic Test: POD risk estimation using PEUMA |
What is being measured
The primary outcome is the main question the study is designed to answer.
Postoperative Delirium
Incidence of POD in the cohort diagnosed using the Confusion Assessment Method (CAM) twice/day
Measured: First 3 days after surgery
Secondary outcomes (6)
Death
Number of deceased patients
Measured: 30 days after surgery
Delirium Severity
Delirium severity assessed by Cognitive Assessment Method - Severity (CAM-S)
Measured: First 3 days after surgery
Delirium Duration
Duration of delirium during the postoperative period
Measured: First 3 days after surgery
Need for Mechanical Ventilation
Number of patients that needed mechanical ventilation
Measured: First 3 days after surgery
Reintervention
Number of patients who required other unanticipated surgery after the primary intervention
Measured: First 3 days after surgery
Unanticipated ICU hospitalization
Number of patients that needed unanticipated intensive care unit (ICU) care
Measured: First 3 days after surgery
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted15 Aug 2023
- Study start1 Sep 2023
- Primary completion31 Oct 2025
- Study completion30 Jun 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (3)Papers the sponsor has linked to this study.
- Other trials for Postoperative DeliriumStudies 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
- Prospective
- Enrolment
- 264 participants (estimated)
- Target duration
- 30 Days
Sponsor and investigators
- Lead sponsor
- University of Chile
- Sponsor type
- University, hospital or other
- Collaborators
- Instituto Nacional del Cancer, Chile, Pontificia Universidad Catolica de Chile, Hospital Base San Jose Osorno, Clinica Santa Maria
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05992506
- Sponsor's protocol ID
- IT21I0041
- Status last verified
- Oct 2025
- First submitted
- 7 Aug 2023
- Last updated
- 20 Nov 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided: Individual participant data might be shared with other researchers only if participants give written consent for that.
Publications
Riley RD, Ensor J, Snell KIE, Harrell FE Jr, Martin GP, Reitsma JB, Moons KGM, Collins G, van Smeden M. Calculating the sample size required for developing a clinical prediction model. BMJ. 2020 Mar 18;368:m441. doi: 10.1136/bmj.m441. No abstract available.
PubMed 32188600Gutierrez R, Egana JI, Saez I, Reyes F, Briceno C, Venegas M, Lavado I, Penna A. Intraoperative Low Alpha Power in the Electroencephalogram Is Associated With Postoperative Subsyndromal Delirium. Front Syst Neurosci. 2019 Oct 18;13:56. doi: 10.3389/fnsys.2019.00056. eCollection 2019.
PubMed 31680886Wong CK, van Munster BC, Hatseras A, Huis In 't Veld E, van Leeuwen BL, de Rooij SE, Pleijhuis RG. Head-to-head comparison of 14 prediction models for postoperative delirium in elderly non-ICU patients: an external validation study. BMJ Open. 2022 Apr 8;12(4):e054023. doi: 10.1136/bmjopen-2021-054023.
PubMed 35396283
Study at a glance
From the registry record, last updated by the sponsor on 20 Nov 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Electroencephalographic Biomarker to Predict the Development of Postoperative Delirium: a Protocol of an Observational Study in a Cohort of Patients From Five Centers
- ClinicalTrials.gov ID
- NCT05992506
- Acronym / sponsor ID
- IT21I0041
- Conditions
- Postoperative Delirium
- Keywords
- EEG, Postoperative Delirium, Risk Assessment, Anesthesia
- Study type
- Observational
- Recruitment status
- Active, not recruiting
- Enrolment
- 264 participants (estimated)
- Lead sponsor
- University of ChileUniversity, hospital or other
- Collaborators
- Instituto Nacional del Cancer, Chile, Pontificia Universidad Catolica de Chile, Hospital Base San Jose Osorno, Clinica Santa Maria
- Study start
- 1 Sep 2023 (actual)
- Primary completion
- 31 Oct 2025 (actual)
- Study completion
- 30 Jun 2026 (estimated)
- First posted
- 15 Aug 2023 (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.
Acute post-operatory cognitive dysfunction states are one of the most important complications in older patients that underwent surgery. Among them postoperative delirium (POD) is the the most studied. Patients who develop delirium have poorer long-term outcomes, such as longer length of hospital stay, institutionalization at discharge, and even higher mortality, and consequently, the human and economic costs significantly increase for the health system. Here the research team will use an observational cohort, investigator blinded in five-center with a primary endpoint to validate intraoperative EEG analysis as a reliable biomarker of postoperative delirium.
Detailed description
Acute post-operatory cognitive dysfunction states are one of the most frequent complications in older patients after surgery, being POD the most important. Previous studies have shown than the incidence of POD in older patients range between 10-50%. Patients who develop POD have poorer long-term outcomes, such as longer length of hospital stay, institutionalization at discharge, and even higher mortality. Consequently, the human and economic costs associated to POD represents an important issue for health systems worldwide.
A key element to diminish POD and its burden on healthcare is early diagnostic. Current risk assessment tools are centered on clinical approaches based on cognitive tests (i.e., MoCA) and/or prediction models that uses patients' clinical variables (i.e., DELPHI score). We have developed a strategy that uses intraoperative EEG features as building blocks for a new POD risk assessment predictive model. This system, called PEUMA, uses data obtained from 95 patients from a previous study (NCT04214496).
This will be a multicenter (five-centers), observational study and its primary outcome will be PEUMA's ability to predict POD.
To calculate the sample size, the methodology described by Riley et al was used. This method is specially designed for clinical prediction models. Such a tool is available online (https://mvansmeden.shinyapps.io/BeyondEPV/). The parameters used were the following:
- Number of predictor candidates: 4
- Fraction of events: 0.22. 22% was used because it is the incidence of POD in the analysis of the preliminary data of the first stage and these are in the reporting range common worldwide.
- Estimation error of the classifier: 0.06. The authors suggest prediction errors small when evaluating binary outcomes (Yes POD/No POD) The calculation indicates a sample size of 240 patients. Considering a loss of 10% (in the preliminary results of the first stage the loss was 8%), the sample size is 264 patients.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Target follow-up
- 30 Days
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Patients at risk of developing POD | – | Diagnostic Test: POD risk estimation using PEUMA* Patients older than 60 years * Scheduled for elective surgery of moderate or high risk (defined as that which requires a subsequent hospitalization of at least 3 days) under general anesthesia. * Signed informed consent. |
Who may qualify
- Ages
- 60 to 100 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
- Study population
- Patients at risk of developing POD will be evaluated in the pre and postoperative period for cognitive dysfunction and the appearance of POD. In the intraoperative period, an EEG-based monitorization will be performed using a SedLine (Masimo, CA) Monitor.
Key inclusion criteria (5 listed)
- Age ≥ 60 years old
- Scheduled for high-risk elective surgery
- Need for at least 3 days of hospital stay after surgery
- Surgery performed under general anesthesia
- Written informed consent for participation in the trial
Key exclusion criteria (9 listed)
- Patients with preoperative delirium or dementia
- Patients using neuroleptics drug during the past 6 months
- Patients with a history of encephalopathy, psychosis, stroke or brain trauma with neurologic sequels
- The use of ketamine or dexmedetomidine during surgery
- Emergency surgery
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 |
|---|---|---|
| POD risk estimation using PEUMAA software will analyze intraoperative EEG recording for the estimation of a POD Risk Index | Diagnostic test | Patients at risk of developing POD |
Primary outcome
Postoperative Delirium
Time frame: First 3 days after surgery
Incidence of POD in the cohort diagnosed using the Confusion Assessment Method (CAM) twice/day
6 secondary outcomes
Death
Time frame: 30 days after surgery
Delirium Severity
Time frame: First 3 days after surgery
Delirium Duration
Time frame: First 3 days after surgery
Need for Mechanical Ventilation
Time frame: First 3 days after surgery
Reintervention
Time frame: First 3 days after surgery
Unanticipated ICU hospitalization
Time frame: First 3 days after surgery
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 20 Nov 2025.
- Results publication: PubMed 32188600Riley RD, Ensor J, Snell KIE, Harrell FE Jr, Martin GP, Reitsma JB, Moons KGM, Collins G, van Smeden M. Calculating the sample size required for developing a clinical prediction model. BMJ. 2020 Mar 18;368:m441. doi: 10.1136/bmj.m441. No abstract available.
- Results publication: PubMed 31680886Gutierrez R, Egana JI, Saez I, Reyes F, Briceno C, Venegas M, Lavado I, Penna A. Intraoperative Low Alpha Power in the Electroencephalogram Is Associated With Postoperative Subsyndromal Delirium. Front Syst Neurosci. 2019 Oct 18;13:56. doi: 10.3389/fnsys.2019.00056. eCollection 2019.
- Results publication: PubMed 35396283Wong CK, van Munster BC, Hatseras A, Huis In 't Veld E, van Leeuwen BL, de Rooij SE, Pleijhuis RG. Head-to-head comparison of 14 prediction models for postoperative delirium in elderly non-ICU patients: an external validation study. BMJ Open. 2022 Apr 8;12(4):e054023. doi: 10.1136/bmjopen-2021-054023.
- Individual participant dataSharing planned: Undecided. Individual participant data might be shared with other researchers only if participants give written consent for that.
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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.
The record lists no contact. Use the official record to reach the sponsor.
2 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Postoperative Delirium, run by University of Chile at 2 sites 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 5 inclusion and 9 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: under way, not looking for participants, as of the sponsor's last update on 20 Nov 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 2 sites 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?
This study is still under way. Results are not available in the source record yet.
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 (time frame: First 3 days after surgery). 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 NCT05992506, which also lists 3 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 20 Nov 2025.