Pain PostoperativeNCT06313320
Intraoperative Electroencephalographic Biomarkers of Postoperative Pain
An observational study of Pain Postoperative and Nociceptive Pain, run by University of Chile at 2 sites in Chile.
Trial summary
The goal of this study is to explore whether specific intraoperative EEG signals (brain waves or neuronal electrical activity) are associated with the severity of acute postoperative pain. Read more about this study
- Who is it for?
- Ages 18 to 60 years
- Conditions the study is for
- Pain Postoperative, Nociceptive Pain
- How many people
- 57 participants
- Where
- 2 sitesChile
- Study dates
- 1 May 2024to 23 Mar 2026
- How long will I take part?
- 3 Months
- 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 18 to 60 years
- All sexes
- No healthy volunteers
- Adult
Study population: Adult patients schedule for elective abdominal surgery under general anesthesia.
Who may be able to join
- American Society of Anesthesiologist Performance Status I or II
- Scheduled for elective laparoscopic abdominal surgery under General Anesthesia
Who cannot join
- Body Mass Index > 35 kg/m2
- Past history or suspected difficult airway
- Craniofacial malformations
- Use of regional anesthesia technique during or after the surgery
- Severe arrhythmia or use of a pacemaker device
- Severe neuropsychiatric illness (Mayor depression, bipolar disorder, schizophrenia)
Show all 14Show fewer
- Regular use of psychoactive drugs
- Any injury in the right hand
- Past history of peripheral neuropathy
- Diabetes Mellitus
- Known lesion in the spinothalamic tract.
- Analgesics used in the past 72 hours
- Known allergy to propofol
- Previous diagnosis of a condition associated with chronic pain (such as fibromyalgia, rheumatoid arthritis, osteoarthritis, migraine)
Trial locations and contacts
2 sites in 1 country.
Chile2 sites
Hospital Clinico de la Universidad de Chile
Santiago, RM, 7563215
Centro de Investigacion Clinica Avanzada
Santiago
About this study
Official title: Determination of the Association of Intraoperative Nociception Electroencephalographic Biomarkers and Postoperative Pain
The goal of this study is to explore whether specific intraoperative EEG signals (brain waves or neuronal electrical activity) are associated with the severity of acute postoperative pain.
Read the detailed description
This is a prospective minimal-risk observational study to collect and analyze EEG data during intraepidermal electrical stimulation in patients receiving general anesthesia (GA) for abdominal surgery. To collect nociception-related EEG signal during GA the investigators designed a standardized Intraepidermal Electrical Stimulation (IES) Protocol. The intensity of the electrical stimulus will be calibrated to each participant perception pre-surgery, with 3 different intensities: sensitivity threshold, mild-pain threshold, and moderate-pain threshold. The IES will be administered several times throughout the surgical procedure: a) At baseline, prior to induction of GA, b) Three minutes after loss of consciousness, c) Five minutes after fentanyl administration and orotracheal intubation, d) Five minutes after first incision and every 20 minutes until the end of the surgery, and f) After surgery ends and before extubation. To standardize the anesthesia management as much as possible, all patients will be attended by a reduced number of anesthesiologists. The hypnosis will be achieved with propofol, while analgesia will be mainly achieved with either fentanyl or remifentanil. EEG will be recorded with a 32-channel high standard equipment. Once the patient arrives to the Post-Anesthesia Care Unit (PACU), the investigators will record the pain reported by the patient using the Numeric Pain Rating Scale every 15 minutes during the first hour, and every 30 minutes until patient is discharged from the PACU. Also, the investigators will both, record opioid administration through the surgery and estimate their effect-site concentration with pharmacokinetic/pharmacodynamic models. Besides, the investigators will measure opioid plasmatic concentrations.
- Conditions
- Pain Postoperative, Nociceptive Pain
- Keywords
- Pain, Nociception, Electroencephalogram
- Medical subject headings
- Pain, Postoperative, Nociceptive Pain, Pain
What is being measured
The primary outcome is the main question the study is designed to answer.
Maximum Pain in PACU
Pain is evaluated several times during PACU stay using the Numeric Rating Scale (from 0 to 10). Discrete Numerical Variable
Measured: From PACU Admission to PACU Discharged, an average of 2 hours
Secondary outcomes (4)
Opioid Consumption in PACU
Total opioid administered during PACU stay in Morphine Milligram Equivalent (MME). Continuous Numerical Variable.
Measured: From PACU Admission to PACU Discharged, an average of 72 hours
Maximum Pain at 24h
Pain is evaluated several times during hospital stay using the Numeric Rating Scale (from 0 to 10). This outcome corresponds to the maximum pain reported by the patient during the time frame. Discrete Numerical Variable.
Measured: From PACU discharged to 24 hours after PACU discharged
Presence of surgical related pain at day 7
Pain of any intensity (Numeric Rating Scale >1) reported by the patient 7 days after the surgery
Measured: 7 days after the surgery (+- 1 day)
Presence of surgical related pain at day 30
Pain of any intensity (Numeric Rating Scale >1) reported by the patient 30 days after the surgery
Measured: 30 days after surgery (+- 3 day)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted15 Mar 2024
- Study start1 May 2024
- Primary completion15 Feb 2026
- Study completion23 Mar 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (4)Papers the sponsor has linked to this study.
- Other trials for Pain PostoperativeStudies 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
- 57 participants (actual)
- Target duration
- 3 Months
Sponsor and investigators
- Lead sponsor
- University of Chile
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Rodrigo Gutierrez, MD, PhD, Principal investigator, University of Chile
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06313320
- Sponsor's protocol ID
- OAIC1344-23
- Status last verified
- Mar 2026
- First submitted
- 6 Mar 2024
- Last updated
- 27 Mar 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Publications
Gan TJ, Habib AS, Miller TE, White W, Apfelbaum JL. Incidence, patient satisfaction, and perceptions of post-surgical pain: results from a US national survey. Curr Med Res Opin. 2014 Jan;30(1):149-60. doi: 10.1185/03007995.2013.860019. Epub 2013 Nov 15.
PubMed 24237004Glare P, Aubrey KR, Myles PS. Transition from acute to chronic pain after surgery. Lancet. 2019 Apr 13;393(10180):1537-1546. doi: 10.1016/S0140-6736(19)30352-6.
PubMed 30983589Garcia PS, Kreuzer M, Hight D, Sleigh JW. Effects of noxious stimulation on the electroencephalogram during general anaesthesia: a narrative review and approach to analgesic titration. Br J Anaesth. 2021 Feb;126(2):445-457. doi: 10.1016/j.bja.2020.10.036.
PubMed 33461725Baharloo R, Principe JC, Fillingim RB, Wallace MR, Zou B, Crispen PL, Parvataneni HK, Prieto HA, Machuca TN, Mi X, Hughes SJ, Murad GJA, Rashidi P, Tighe PJ. Slow Dynamics of Acute Postoperative Pain Intensity Time Series Determined via Wavelet Analysis Are Associated With the Risk of Severe Postoperative Day 30 Pain. Anesth Analg. 2021 May 1;132(5):1465-1474. doi: 10.1213/ANE.0000000000005385.
PubMed 33591118
Study at a glance
From the registry record, last updated by the sponsor on 27 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Determination of the Association of Intraoperative Nociception Electroencephalographic Biomarkers and Postoperative Pain
- ClinicalTrials.gov ID
- NCT06313320
- Acronym / sponsor ID
- OAIC1344-23
- Conditions
- Pain Postoperative, Nociceptive Pain
- Keywords
- Pain, Nociception, Electroencephalogram
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 57 participants (actual)
- Lead sponsor
- University of ChileUniversity, hospital or other
- Study start
- 1 May 2024 (actual)
- Primary completion
- 15 Feb 2026 (actual)
- Study completion
- 23 Mar 2026 (actual)
- First posted
- 15 Mar 2024 (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.
The goal of this study is to explore whether specific intraoperative EEG signals (brain waves or neuronal electrical activity) are associated with the severity of acute postoperative pain.
Detailed description
This is a prospective minimal-risk observational study to collect and analyze EEG data during intraepidermal electrical stimulation in patients receiving general anesthesia (GA) for abdominal surgery. To collect nociception-related EEG signal during GA the investigators designed a standardized Intraepidermal Electrical Stimulation (IES) Protocol. The intensity of the electrical stimulus will be calibrated to each participant perception pre-surgery, with 3 different intensities: sensitivity threshold, mild-pain threshold, and moderate-pain threshold. The IES will be administered several times throughout the surgical procedure: a) At baseline, prior to induction of GA, b) Three minutes after loss of consciousness, c) Five minutes after fentanyl administration and orotracheal intubation, d) Five minutes after first incision and every 20 minutes until the end of the surgery, and f) After surgery ends and before extubation. To standardize the anesthesia management as much as possible, all patients will be attended by a reduced number of anesthesiologists. The hypnosis will be achieved with propofol, while analgesia will be mainly achieved with either fentanyl or remifentanil. EEG will be recorded with a 32-channel high standard equipment. Once the patient arrives to the Post-Anesthesia Care Unit (PACU), the investigators will record the pain reported by the patient using the Numeric Pain Rating Scale every 15 minutes during the first hour, and every 30 minutes until patient is discharged from the PACU. Also, the investigators will both, record opioid administration through the surgery and estimate their effect-site concentration with pharmacokinetic/pharmacodynamic models. Besides, the investigators will measure opioid plasmatic concentrations.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Target follow-up
- 3 Months
Who may qualify
- Ages
- 18 to 60 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult
- Study population
- Adult patients schedule for elective abdominal surgery under general anesthesia.
Key inclusion criteria (2 listed)
- American Society of Anesthesiologist Performance Status I or II
- Scheduled for elective laparoscopic abdominal surgery under General Anesthesia
Key exclusion criteria (14 listed)
- Body Mass Index > 35 kg/m2
- Past history or suspected difficult airway
- Craniofacial malformations
- Use of regional anesthesia technique during or after the surgery
- Severe arrhythmia or use of a pacemaker device
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Maximum Pain in PACU
Time frame: From PACU Admission to PACU Discharged, an average of 2 hours
Pain is evaluated several times during PACU stay using the Numeric Rating Scale (from 0 to 10). Discrete Numerical Variable
4 secondary outcomes
Opioid Consumption in PACU
Time frame: From PACU Admission to PACU Discharged, an average of 72 hours
Maximum Pain at 24h
Time frame: From PACU discharged to 24 hours after PACU discharged
Presence of surgical related pain at day 7
Time frame: 7 days after the surgery (+- 1 day)
Presence of surgical related pain at day 30
Time frame: 30 days after surgery (+- 3 day)
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 27 Mar 2026.
- Background: PubMed 24237004Gan TJ, Habib AS, Miller TE, White W, Apfelbaum JL. Incidence, patient satisfaction, and perceptions of post-surgical pain: results from a US national survey. Curr Med Res Opin. 2014 Jan;30(1):149-60. doi: 10.1185/03007995.2013.860019. Epub 2013 Nov 15.
- Background: PubMed 30983589Glare P, Aubrey KR, Myles PS. Transition from acute to chronic pain after surgery. Lancet. 2019 Apr 13;393(10180):1537-1546. doi: 10.1016/S0140-6736(19)30352-6.
- Background: PubMed 33461725Garcia PS, Kreuzer M, Hight D, Sleigh JW. Effects of noxious stimulation on the electroencephalogram during general anaesthesia: a narrative review and approach to analgesic titration. Br J Anaesth. 2021 Feb;126(2):445-457. doi: 10.1016/j.bja.2020.10.036.
- Background: PubMed 33591118Baharloo R, Principe JC, Fillingim RB, Wallace MR, Zou B, Crispen PL, Parvataneni HK, Prieto HA, Machuca TN, Mi X, Hughes SJ, Murad GJA, Rashidi P, Tighe PJ. Slow Dynamics of Acute Postoperative Pain Intensity Time Series Determined via Wavelet Analysis Are Associated With the Risk of Severe Postoperative Day 30 Pain. Anesth Analg. 2021 May 1;132(5):1465-1474. doi: 10.1213/ANE.0000000000005385.
- Individual participant dataSharing planned: Undecided
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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.
Rodrigo Gutierrez, MD, PhD principal investigator
University of Chile
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 Pain Postoperative and Nociceptive Pain, 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 2 inclusion and 14 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: finished, as of the sponsor's last update on 27 Mar 2026. 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?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
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?
Maximum Pain in PACU (time frame: From PACU Admission to PACU Discharged, an average of 2 hours). 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 NCT06313320, which also lists 4 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 27 Mar 2026.