Intraoperative Electroencephalographic Biomarkers of Postoperative Pain

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.

Study Overview

• Status: Not yet recruiting
• Conditions: Nociceptive Pain; Pain Postoperative

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 Type: Observational
• Enrollment (Estimated): 80

Contacts and Locations

• Study Contact: Name: Rodrigo Gutierrez, MD, PhD; Phone Number: +56995993665; Email: rodrgutierrez@uchile.cl

Study Locations

• Chile
  • Santiago, Chile
    • Centro de Investigacion Clinica Avanzada
  • RM
    • Santiago, RM, Chile, 7563215
      • Hospital Clinico de la Universidad de Chile
      • Contact: Rodrigo Gutierrez, MD, PhD; Phone Number: +56995993665; Email: rodrgutierrez@uchile.cl

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Probability Sample

Study Population

Adult patients schedule for elective abdominal surgery under general anesthesia.

Description

Inclusion Criteria:

• American Society of Anesthesiologist Performance Status I or II
• Scheduled for elective laparoscopic abdominal surgery under General Anesthesia

Exclusion Criteria:

• 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)
• 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)

Study Plan

How is the study designed?

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Maximum Pain in PACU	Pain is evaluated several times during PACU stay using the Numeric Rating Scale (from 0 to 10). Discrete Numerical Variable	From PACU Admission to PACU Discharged, an average of 2 hours

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Opioid Consumption in PACU	Total opioid administered during PACU stay in Morphine Milligram Equivalent (MME). Continuous Numerical Variable.	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.	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	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	30 days after surgery (+- 3 day)

Collaborators and Investigators

• Sponsor: University of Chile
• Investigators: Principal Investigator: Rodrigo Gutierrez, MD, PhD, University of Chile

Publications and helpful links

General 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.
• Glare 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.
• Garcia 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.
• Baharloo 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.

Study record dates

Study Major Dates

• Study Start (Estimated): March 1, 2024
• Primary Completion (Estimated): March 1, 2026
• Study Completion (Estimated): June 1, 2026

Study Registration Dates

• First Submitted: March 6, 2024
• First Submitted That Met QC Criteria: March 12, 2024
• First Posted (Actual): March 15, 2024

Study Record Updates

• Last Update Posted (Actual): March 15, 2024
• Last Update Submitted That Met QC Criteria: March 12, 2024
• Last Verified: December 1, 2023

More Information

Terms related to this study

• Keywords: Pain; Electroencephalogram; Nociception
• Additional Relevant MeSH Terms: Pathologic Processes; Postoperative Complications; Pain; Neurologic Manifestations; Pain, Postoperative; Nociceptive Pain
• Other Study ID Numbers: OAIC1344-23

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