Impact of Estimated Concentration of Propofol on Implicit Memory Formation

June 5, 2026 updated by: Federico Linassi, University of Padova

Impact of Target Controlled Infusion Estimated Concentration of Propofol on Implicit Memory Formation During Propofol-Remifentanil General Anaesthesia

Implicit memory formation and learning during general anaesthesia is a still debated question and no anesthetic regimen (ie intravenous anaesthesia vs inhalatory one) nor analgesic regimen (i.e. low or high opioids usage) has been identified for prevention.

With this study the investigators aim to investigate if, during Total Intravenous Anaesthesia with Target Controlled Infusion (TIVA-TCI) different concentrations of Propofol at loss of responsiveness, maintenance and return of responsiveness can have a role in implicit memory formation.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Detailed Description

Implicit memory formation and learning during general anaesthesia is a still debated question and no anesthetic regimen (ie intravenous anaesthesia vs inhalatory one) nor analgesic regimen (i.e. low or high opioids usage) has been identified for prevention.

With this study the investigators aim to investigate if, during Total Intravenous Anaesthesia with Target Controlled Infusion (TIVA-TCI) different concentrations of Propofol at loss of responsiveness (CeP RoR), maintenance (CePMA) and return of responSiveness (CeP RoR) can have a role in implicit memory formation.

20 most common italiaN words will be continuously presented to the anaesthetized patients from Loss of responsiveness to end of surgery.

CeP RoR, MA and LoR, as well as patient state index (PSi) from Sedline monitor for hypnosis level monitoring will be recorded.

Within 24 hours, a trained psychologist will be present the patients the Word Steam Recognition Test, Free Recall and Force Choice recognition task to asses the presence of implicit memory formation. A second group, who did not hear the words, will be investigated to assess the role of chance in the above-mentioned test.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Observational

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
80

Contacts and Locations

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

Study Locations

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

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

N/A

Sampling Method

Probability Sample

Study Population

Breast-Surgery women undergoing TIVA-TCI

Description

Inclusion Criteria:

  • General anaesthesia with TIVA-TCI

Exclusion Criteria:

  • ASA > III
  • Benzodiazepines premedication
  • Neurological/Psychiatric disease

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

Cohorts and Interventions

Group / Cohort

Group / Cohort

A group or subgroup of participants in an observational study that is assessed for biomedical or health outcomes.
Cases
Patients who, during general anaesthesia, will hear the 20 words and will be tested form implicit memory formation.
Controls
Patients who, during general anaesthesia, will not hear the 20 words and will be tested form implicit memory formation to assess the role of chance on the tests adopted

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
The role of Propofol Concentration at the loss of responsiveness on Implicit Memory formation
Time Frame: CeP will be recorded at Loss of responsiveness. Word Steam recognition, Free recall and Forced Choice Recognition Task will be performed within 12-24 hours after surgery. These 3 tests are analysed togheter to check for implicit memory formation.
CeP at LOR will be compared between patients who exhibit or not implicit memory formation.
CeP will be recorded at Loss of responsiveness. Word Steam recognition, Free recall and Forced Choice Recognition Task will be performed within 12-24 hours after surgery. These 3 tests are analysed togheter to check for implicit memory formation.
The role of Propofol Concentration at the maintenance of anaesthesia on Implicit Memory formation
Time Frame: CeP will be recorded during anaesthesia maintenance. Word Steam recognition, Free recall and Forced Choice Recognition Task will be performed within 12-24 hours after surgery. These 3 tests are analysed togheter to check for implicit memory formation.
CeP at anaesthesia maintenance will be compared between patients who exhibit or not implicit memory formation.
CeP will be recorded during anaesthesia maintenance. Word Steam recognition, Free recall and Forced Choice Recognition Task will be performed within 12-24 hours after surgery. These 3 tests are analysed togheter to check for implicit memory formation.
The role of Propofol Concentration at the return of responsiveness on Implicit Memory formation
Time Frame: CeP will be recorded at Return of responsiveness. Word Steam recognition, Free recall and Forced Choice Recognition Task will be performed within 12-24 hours after surgery. These 3 tests are analysed togheter to check for implicit memory formation.
CeP at ROR will be compared between patients who exhibit or not implicit memory formation.
CeP will be recorded at Return of responsiveness. Word Steam recognition, Free recall and Forced Choice Recognition Task will be performed within 12-24 hours after surgery. These 3 tests are analysed togheter to check for implicit memory formation.

Collaborators and Investigators

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

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
University of Padova

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)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
July 1, 2024

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
October 31, 2026

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
November 15, 2026

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
July 1, 2024

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
July 9, 2024

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
July 12, 2024

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
June 8, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
June 5, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
June 1, 2026

More Information

Terms related to this study

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • ImpliMAST

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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