The Effect of Remifentanil on the Objectively Measured Pressure Pain Threshold

NCT07568405 | Enrolling By Invitation

• 1 other identifier: HUB2025549
• Study Type: interventional
• Target: 40
• Locations: 1 country
• Sites: 1

Brief Summary

It is a clinical study investigating the relationship between objectively measured pain threshold and the need for escalating doses of remifentanyl opioids. This study is expected to include approximately 40 participants. The aim of the study is to objectively measure the analgesic effect of an increasing dose of opioids just before anesthesia.

Conditions

Pain Threshold; Surgery; Postoperative Pain; Intravenous Anesthesia

Keywords

pain threshold; posoperative pain; remifentanil

Outcome Measures

Primary Outcomes (1)

• Measurement of the variation in the pressure pain threshold

  Change in mechanical pain threshold measured objectively using an algometer (AlgoMed®) at increasing plasma concentrations of remifentanil (0, 1, 2, and 3 ng/mL) during the preoperative period. The pain threshold is defined as the pressure (in kilopascals) at which the patient first reports pain during a standardized mechanical stimulus.

  Measurement of the mechanical pressure pain threshold will be initiated upon the participant's arrival in the operating room. The procedure is expected to last approximately 10-15 minutes and will be followed by induction of anesthesia.

Secondary Outcomes (1)

• Correlation between preoperative pain threshold and total postoperative morphine consumption

  From the day of surgery, prior to anesthesia induction, until 24 hours postoperatively.

Study Arms (1)

Pressure pain theshold measured under remifentanil (Ultiva®) infusion and analgesic consumption

EXPERIMENTAL

This is a single-arm study in which all patients will follow the same protocol. Study participation begins on the day of surgery, immediately prior to anesthesia induction, when the primary measurements are performed, and ends 24 hours postoperatively. During this period, analgesic consumption and adverse events will be monitored. Intervention 1: Pressure pain threshold under remifentanil infusion. Pressure pain threshold will be assessed using an algometer at baseline (0 ng/mL) and during stepwise increases in target-controlled intravenous remifentanil (Ultiva®) concentrations of 1, 2, and 3 ng/mL. Measurements will be obtained at each concentration level after achieving steady-state conditions. Intervention 2: Postoperative analgesic consumption and adverse events. Perioperative and postoperative analgesic drug consumption will be recorded. All adverse events will be systematically monitored and documented.

Device: Pressure pain theshold measured under remifentanil (ultiva®) infusion; Drug: Postoperative PCA IV morphine (Sterop®) consumption and adverse events history

Interventions

Pressure pain theshold measured under remifentanil (ultiva®) infusion DEVICE

Upon arrival in the operating room, the patient will undergo standard monitoring, including non-invasive blood pressure, electrocardiography (ECG), pulse oximetry (SpO₂), bispectral index (BIS™), and train-of-four (TOF) monitoring. An intravenous (IV) line will be placed, and crystalloid infusion will be initiated. Mechanical pain threshold will then be assessed using a Medoc algometer. Measurements will be performed on the dorsum of the non-dominant hand. Four measurements will be obtained at different target plasma concentrations of remifentanil(Ultiva®): 0, 1, 2, and 3 ng/mL. Remifentanil will be administered using a target-controlled infusion (TCI) system based on the Minto pharmacokinetic model. Following completion of these measurements, standardized intravenous anesthesia will be induced and maintained using propofol (propolipid®), remifentanil, and rocuronium (B.Braun®). Total perioperative consumption of remifentanil and propofol will be recorded.

Pressure pain theshold measured under remifentanil (Ultiva®) infusion and analgesic consumption

Postoperative PCA IV morphine (Sterop®) consumption and adverse events history DRUG

At the end of the surgical procedure, intravenous acetaminophen 1 g and a 4 mg morphine bolus will be administered. Upon arrival in the post-anesthesia care unit (PACU), pain will be assessed using the visual analogue scale (VAS). During the first 24 postoperative hours, analgesia will be provided via a patient-controlled analgesia (PCA) pump delivering 2 mg intravenous HCL morphine (Sterop®) boluses on demand. The PCA settings will follow a 2/10/20 regimen: 2 mg morphine per demand dose, a 10-minute lockout interval, and a maximum dose of 20 mg over 4 hours. The use of acetaminophen as adjunct analgesia is permitted; however, corticosteroids, nonsteroidal anti-inflammatory drugs (NSAIDs), piritramide, and magnesium are prohibited. Pain scores (VAS) will be reassessed at 12 and 24 hours postoperatively. All adverse events (e.g., nausea, delirium) will be monitored and recorded during the 24-hour postoperative period.

Pressure pain theshold measured under remifentanil (Ultiva®) infusion and analgesic consumption

Eligibility Criteria

• Age: 18 Years - 65 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Adult patients who are able to volunteer
• ASA 1, 2and 3

You may not qualify if:

• Refusal to participate;
• Body mass index (BMI) \> 30 kg/m²;
• Allergy to any medication used for anesthesia;
• Chronic pain or regular use of analgesics;
• Severe ventricular dysfunction, pulmonary hypertension, or uncontrolled arrhythmia;
• Non-elective surgery;
• Participation in another study within the last 3 months;
• Pregnancy or breastfeeding;
• Severe renal or hepatic impairment

Sponsors & Collaborators

• Université Libre de Bruxelles: lead

Study Sites (1)

HUB Erasme

Brussels, Brussels Capital, 1070, Belgium

Location

MeSH Terms

Conditions

Pain, Postoperative

Interventions

Economics

Condition Hierarchy (Ancestors)

Postoperative Complications; Pathologic Processes; Pathological Conditions, Signs and Symptoms; Pain; Neurologic Manifestations; Signs and Symptoms

Intervention Hierarchy (Ancestors)

Health Care Economics and Organizations

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: PREVENTION
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principal investigator

Study Record Dates

• First Submitted: March 17, 2026
• First Posted: May 5, 2026
• Study Start: January 26, 2026
• Primary Completion (Estimated): June 15, 2026
• Study Completion (Estimated): June 15, 2026
• Last Updated: May 5, 2026

Record last verified: 2026-04

Data Sharing

• IPD Sharing: Will not share

Locations

BE (1)