Clinical Trial Using Pupillometry to Measure Nociception in Healthy Volunteers.

Study Overview
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Brief Summary
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Pupillometry has been used in healthy volunteers to investigate the usefulness of the pupil light reflex as an indicator of pain intensity on pressure as a nociceptive stimulus. In this sense, it is necessary to check if the pupillometry is sensitive to different types or sources of pain. One of these devices is the Algiscan® portable pupillometer (IdMed, Marseille, France), which we propose to use in the present study. This pupillometer has previously been used in healthy volunteers, and in patients admitted to the intensive care unit, subjected to mechanical ventilation and sedation / analgesia. This study in healthy volunteers aims to evaluate whether the PDR can be a reliable and discriminatory measure of the intensity of nociception, applying various types of nociceptive stimuli. If so, this study could lead to the use of pupillometry as an objective measure of nociception in settings where patients cannot communicate, such as intensive care areas or perioperative settings.

Official Title
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Crossover Randomized Clinical Trial to Evaluate the Effectiveness and Safety of Pupillometry as an Objective Measurement of Nociception in Healthy Volunteers.

Conditions
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Nociceptive Pain, Pupillary Light Reflex Lost, Healthy, Pain, Procedural, Gender, Anxiety

Intervention / Treatment
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* Device: CE marked medical device
* Device: Algometer
* Procedure: Comparator


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Subjects of both sexes (balanced) Caucasian race Ages between 25 and 65 years old (balanced, 50% from 25-45 and 50% from 45-65) Body weight within the normal range (Quetelet index: 19-30) Clinical history, physical examination and vital signs within normality Free acceptance to participate, with written informed consent Exclusion Criteria: Previous history of alcoholism or drug dependence (year prior to the screening visit or daily alcohol consumption> 40 gr / day for men or> 24 gr / day for women) Significant consumption of stimulating drinks (> 5 coffees, teas, chocolate or cola drinks / day). Taking any medication in the 15 days prior to the study and / or medicinal plants that may have an effect on the pupil (beta-blockers, droperidol, metoclopramide, clonidine ...). Oral contraceptives and paracetamol will be allowed. Pregnancy (β-hCG test). Menstruation and / or dysmenorrhea on the day of the study Family or personal history or clinical evidence of psychiatric, neurological or ophthalmological problems: anxiety, depression, Parkinson's, glaucoma, dry eyes, retinal diseases, eye surgery and pupil abnormalities, presenting migraine pathology and diabetes Pupillary diameter ≥ 5mm Smokers or ex-smokers <6 months. Have participated in a clinical trial in the 3 months prior to the start of this study.

Ages Eligible for Study
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Minimum Age: 25 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Other
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: threshold stimulation (tetanic)<br> | Device: CE marked medical device<br>* Tetanic stimulation<br>|
| Experimental: upper threshold stimulation (tetanic)<br> | Device: CE marked medical device<br>* Tetanic stimulation<br>|
| Experimental: threshold stimulation (pressure)<br> | Device: Algometer<br>* Pressure stimulation<br>|
| Experimental: upper threshold stimulation (pressure)<br> | Device: Algometer<br>* Pressure stimulation<br>|
| Placebo Comparator: non nociceptive procedure (fine touch)<br> | Procedure: Comparator<br>* Non-nociceptive procedure (fine touch)<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Pupillary Dilatation Reflex (PDR) | Measure of Pupillary Dilatation Reflex (PDR) in % obtained by AlgiScan® | Change in Pupillary Dilatation Reflex (PDR) from baseline to +10 minutes (with non-nociceptive procedure (fine touch)) | 
| Change in Pupillary Dilatation Reflex (PDR) | Measure of Pupillary Dilatation Reflex (PDR) in % obtained by AlgiScan® after tetanic stimulation (by Algiscan®) | Change in Pupillary Dilatation Reflex (PDR) from baseline to 20 minutes after tetanic stimulation (by Algiscan®) | 
| Change in Pupillary Dilatation Reflex (PDR) | Measure of Pupillary Dilatation Reflex (PDR) in % obtained by AlgiScan® after tetanic stimulation (by Algiscan®) | Change in Pupillary Dilatation Reflex (PDR) from baseline to 30 minutes after tetanic stimulation (by Algiscan®) | 
| Change in Pupillary Dilatation Reflex (PDR) | Measure of Pupillary Dilatation Reflex (PDR) in % obtained by AlgiScan® after tetanic stimulation (by Algiscan®) | Change in Pupillary Dilatation Reflex (PDR) from baseline to 40 minutes after tetanic stimulation (by Algiscan®) | 
| Change in Pupillary Dilatation Reflex (PDR) | Measure of Pupillary Dilatation Reflex (PDR) in % obtained by AlgiScan® after tetanic stimulation (by Algiscan®) | Change in Pupillary Dilatation Reflex (PDR) from baseline to 50 minutes after tetanic stimulation (by Algiscan®) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Pupillary Dilatation Reflex (PDR) | Measure of Pupillary Dilatation Reflex (PDR) in % obtained by AlgiScan® after pressure estimulation (by algometer Somedic®) | Change in Pupillary Dilatation Reflex (PDR) from baseline to + 60 minutes after pressure estimulation | 
| Change in Pupillary Dilatation Reflex (PDR) | Measure of Pupillary Dilatation Reflex (PDR) in % obtained by AlgiScan® after pressure estimulation (by algometer Somedic®) | Change in Pupillary Dilatation Reflex (PDR) from baseline to +70 minutes after pressure estimulation | 
| Change in Pupillary Dilatation Reflex (PDR) | Measure of Pupillary Dilatation Reflex (PDR) in % obtained by AlgiScan® after pressure estimulation (by algometer Somedic®) | Change in Pupillary Dilatation Reflex (PDR) from baseline to +80 minutes after pressure estimulation | 
| Change in Pupillary Dilatation Reflex (PDR) | Measure of Pupillary Dilatation Reflex (PDR) in % obtained by AlgiScan® after pressure estimulation (by algometer Somedic®) | Change in Pupillary Dilatation Reflex (PDR) from baseline to +90 minutes after pressure estimulation |