Analgesic Territory Assessment of the Spinal Erector Block Using Pupillometry

Study Overview
=================
Brief Summary
-----------------
Few works have studied the area of analgesia covered by the spinal erector block in an objective manner, especially on the cephalo-caudal spread. The available data are dissection works or subjective data such as thermoalgesic or epicritic sensitivity. This information would however be relevant in order to propose a better analgesia. Indeed, it could explain certain failures by insufficient diffusion of the block. The use of a multistage block could be relevant, especially in the case of osteosynthesis on several vertebral levels.

Detailed Description
-----------------
Pupillometry makes possible to monitor analgesia based on the pupillary dilation reflex to pain. The goal is to establish an objective mapping of these type of analgesia from these data.

Official Title
-----------------
Analgesic Territory Assessment of the Spinal Erector Block Using Pupillometry

Conditions
-----------------
Anesthesia, Local

Intervention / Treatment
-----------------
* Other: data collected


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Patients receiving erector spinae block for pain management of spinal osteosynthesis Exclusion Criteria: Patient refusal Known allergy to local anesthetics Contraindication to locoregional anesthesia (haemostasis disorder, infection, peripheral neuropathy) Technical impossibility to perform a spinal erector block Pathology with dysautonomia altering the pupillary reflex: diabetes mellitus with diabetic retinopathy, multiple sclerosis, systemic amyloidosis, uncontrolled hypertension, glaucoma Current treatment likely to alter pupillary dilation reflex to pain : antiemetic (droperidol, metoclopramide), alpha-2 agonist (clonidine) Serious psychiatric history Drug abuse Pregnancy

Ages Eligible for Study
-----------------
Minimum Age: 18 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| erector spinae block<br>Patients receiving erector spinae block for pain management of spinal osteosynthesis. Pupillometer will be realized during analgesia (usual practice). | Other: data collected<br>* data collected: Morphological data of the patients Data of the erector block realization Pupillometric data :the variation of the pupil size on stimulation (in percentage of the base diameter)<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| variation of the pupil size (in percentage) | Evaluation the territory covered by the spinal erector block by variation of the pupil size (in percentage). Variation of the pupil size on stimulation will allow to deduce if the dermatome is covered by the spinal erector block analgesia. | During the surgery | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
spinal erector block, pupillometry, loco-regional anesthesia, osteosynthesis