Pupillary Response to Incremental Tetanic Stimulations Under Propofol-remifentanil TCI

Study Overview
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Brief Summary
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In patients under standardized steady-state general anesthesia, 6 tetanic stimulations of incremental intensities were applied to the patients. Pupillary dilation in response to these stimulations was recorded.

Detailed Description
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The aim of the study was to investigate a possible correlation between the intensity of a nociceptive stimulus and the magnitude of pupillary reflex dilation in patients anesthetized with propofol and remifentanil target-controlled infusion. Anesthetic protocol: 10 minutes of steady-state general anesthesia (before extubation during a scheduled gynecological surgery) with remifentanil target concentration of 1 ng/ml, and propofol target concentration adjusted to maintain bispectral index between 45 and 55. Study period: 6 tetanic stimulations of incremental intensities were applied to the patients: 10, 20, 30, 40, 50, 60 milliamps Pupillary dilation in response to these stimulations was recorded. Then, propofol and remifentanil infusions were discontinued, and patients were extubated.

Official Title
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Pupillary Diameter Variations in Response to Tetanic Stimulations of Incremental Intensities in Patients Under Propofol-remifentanil TCI

Conditions
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Pain

Intervention / Treatment
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* Procedure: general anesthesia for scheduled gynecological surgery
* Drug: Propofol
* Drug: Remifentanil, Ultiva®
* Procedure: tetanic stimulations
* Device: VideoAlgesiGraph


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Scheduled gynecological surgery requiring general anesthesia and orotracheal intubation written informed consent Exclusion Criteria: ophthalmic disease neurologic disease preoperative chronic pain or pain medication medication interfering with autonomous nervous system (beta blockers, alpha agonists, metoclopramide, droperidol, atropine, catecholamines)

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Diagnostic
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: pupillometry<br>General anesthesia for scheduled gynecological surgery Propofol target concentration adjusted to maintain bispectral index between 45 and 55 for 10 minutes Remifentanil target concentration 1 ng/ml for 10 minutes Tetanic stimulations of 10-20-30-40-50-60 milliamps (5 seconds per stimulation, 2 minutes between stimulations) Continuous pupillometry VideoAlgesiGraph | Procedure: general anesthesia for scheduled gynecological surgery<br> <br> Drug: Propofol<br>* continuous infusion, target concentration adjusted to maintain bispectral index between 45 and 55<br>Drug: Remifentanil, Ultiva®<br>* continuous infusion, target concentration 1 ng/ml<br>Procedure: tetanic stimulations<br>* 10-20-30-40-50-60 milliamps, 5 seconds, 100 Hertz 2 minutes between stimulations delivered via the standard neuromuscular blocking agents monitor<br>Device: VideoAlgesiGraph<br>* non invasive infrared camera placed in front of the left eye of the patients during the study period, connected to a laptop. No part of the device touches the eye.<br>* Other names: VideoAlgesiGraph, Synapsis (TM), Marseille, France;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Pupillary diameter | as measured by VideoAlgesiGraph, in mm | 5 seconds before tetanic stimulation | 
| Pupillary diameter | as measured by VideoAlgesiGraph, in mm | 1 minute after tetanic stimulation | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Heart rate | as measured by the standard cardioscope | 5 seconds before tetanic stimulation | 
| Heart rate | as measured by the standard cardioscope | 1 minute after tetanic stimulation | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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general anesthesia