Macrophage/Monocyte Driven Inflammation and Anesthetic Sensitivity in Aging (MACRO-AGE)

January 19, 2026 updated by: University of Chile

Role of Macrophage/Monocyte Mediated Inflammatory Response in Diminished Anesthetic Requirements During Aging

The goal of this observational study is to determine whether macrophage/monocyte mediated inflammatory signaling contributes to reduced anesthetic requirements in older adults undergoing major abdominal surgery. The main questions it aims to answer are:

  • Is there a difference in anesthetic dosing requirements (minimum effective dose) between young and older patients undergoing major abdominal surgery?
  • How do electroencephalographic (EEG) signatures under anesthesia correlate with age and systemic inflammatory markers?
  • Is there an association between age, levels of circulating inflammatory cytokines, and monocyte/macrophage phenotypes with anesthetic requirements?

If there is a comparison group: Researchers will compare older adult patients undergoing major abdominal surgery to younger adult patients undergoing major abdominal surgery to see if macrophage/monocyte-mediated inflammatory signaling influences anesthetic sensitivity and the risk of postoperative neurocognitive complications in the older population.

Participants will:

  • Receive general anesthesia for major abdominal surgery, with continuous recording of anesthetic dose requirements.
  • Undergo electroencephalographic (EEG) monitoring during the anesthetic period.
  • Provide blood samples for the measurement of circulating inflammatory cytokines and the assessment of monocyte phenotypes.
  • Provide peritoneal tissue samples (collected during surgery) to evaluate tissue macrophage populations.
  • Provide cerebrospinal fluid (CSF) samples to assess biomarkers of blood-brain barrier permeability.

Study Overview

Status

Not yet recruiting

Conditions

Study Type

Observational

Enrollment (Estimated)

60

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: Catalina Andrea Díaz Papapietro, Anesthesiologist, MD PhD (c)
  • Phone Number: +56229789405
  • Email: catalinadiaz@ug.uchile.cl

Study Contact Backup

  • Name: Rodrigo Gutiérrez Rojas, Assitant Professor, MD PhD
  • Phone Number: +56229789405
  • Email: rodrgutierrez@uchile.cl

Study Locations

  • Chile
    • Santiago Metropolitan
      • Santiago, Santiago Metropolitan, Chile
        • Hospital Clínico Universidad de Chile
        • Contact:

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

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

Adult patients from Hospital Clínico Universidad de Chile, in Santiago de Chile, that require elective abdominal surgery and are willing to participate in the study, meeting inclusion criteria and signing the informed consent.

Description

Inclusion Criteria:

  • Age between 18-30 years or over 60 years old
  • Scheduled for abdominal surgery
  • General anesthesia planned with or without spinal anesthesia
  • Able and willing to provide written informed consent.

Exclusion Criteria:

  • Chemotherapy or systemic corticosteroid use within the past 2 weeks.
  • Pregnancy.
  • Active sepsis or systemic infection.
  • Emergency surgery.
  • Requirement of ketamine or dexmedetomidine during the first hour of anesthesia.
  • History or diagnosis of: stroke with persistent neurological deficit, dementia, Alzheimer's disease, Huntington's disease, amyotrophic lateral sclerosis, central nervous system autoimmune disorders, systemic autoimmune diseases, or infectious diseases of the central nervous system.
  • Current treatment with immunomodulatory medications.
  • Psychiatric disorders with psychotic features.
  • Use of psychoactive or psychotropic recreational drugs within the week prior to surgery.

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
Older adults
Men and women requiring abdominal surgery aged 60 years or older.
Young Adults
Men and women requiring abdominal surgery, aged 30 years or younger.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Frontal EEG alpha-band power
Time Frame: Perioperative
Relative EEG alpha power during surgery under general anesthesia guided by standard age-adjusted dosing
Perioperative

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Time-to-loss of consciousness
Time Frame: Perioperative
During propofol slow induction, the time required for unresponsiveness to verbal stimuli
Perioperative
Intraoperative anesthetic requirements
Time Frame: Perioperative
Total dose and infusion rate of propofol and/or sevoflurane adjusted using frontal EEG monitoring
Perioperative
Time to emergence
Time Frame: Perioperative
Time in minutes to eye opening since end of anesthesia, with verbal stimuli.
Perioperative
Cytokine circulating profile
Time Frame: Baseline
Serum inflammatory cytokine profile
Baseline
Monocyte/Macrophage phenotype in blood and peritoneal samples
Time Frame: Periprocedural
inflammatory cell Pheontype present in circulating blood (monocytes) and in peritoneal lavage and tissue samples.
Periprocedural
Blood-brain barrier permeability
Time Frame: Baseline
CSF biomarkers present: albumin, cytokines.
Baseline

Collaborators and Investigators

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

Sponsor

University of Chile

Investigators

  • Study Chair: Antonello Penna Silva, Anesthesia Professor, MD PhD, Brain and Anesthesia Laboratory (BAL), University of Chile

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 (Estimated)

January 25, 2026

Primary Completion (Estimated)

April 15, 2027

Study Completion (Estimated)

June 15, 2027

Study Registration Dates

First Submitted

November 17, 2025

First Submitted That Met QC Criteria

January 19, 2026

First Posted (Actual)

January 28, 2026

Study Record Updates

Last Update Posted (Actual)

January 28, 2026

Last Update Submitted That Met QC Criteria

January 19, 2026

Last Verified

January 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • OAIC N°1538/25

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

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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