Evaluation of the Analgesia Nociception Index and Videopupillometry to Predict a Child's Post-tonsillectomy Morphine Prescription (ENIGME)

July 28, 2025 updated by: University Hospital, Limoges

Some surgeries, such as tonsillectomies, are particularly painful postoperatively because they are not very accessible to a complementary technique of loco-regional anesthesia and require the use of opioids in the postoperative period.

The use of opioids, in combination with usual analgesics, is common after this surgery. However, some risks are associated with the use of morphine in children, including more frequent respiratory distress, nausea and vomiting, and can cause hemorrhagic complications and lengthen the duration of hospitalization. Decreasing the consumption of morphine drugs is therefore a real challenge.

Although there is no randomized controlled study on the use of standard analgesics with or without morphine to date, a number of studies suggest that the use of morphine should not be systematic after a surgery.

The need for opioids after tonsillectomy as well as the level of pain vary between patients. Some teams use morphine at the end of general anesthesia to prevent pain on waking and others use it only if needed, once the child is awake.

Pain assessment scales are used in the Post-interventional Monitoring Room (PIMR) to adapt these analgesic therapies according to the intensity of pain. One of the validated and frequently used scales in pediatric PIMR is FLACC (Face Legs Activity Cry Consolability). Monitoring tools are also available to evaluate the quality of intraoperative analgesia in unconscious children :

  • the analysis of the pupillary variation in response to a painful stimulus by videopupillometry,
  • and the ANI (Analgesia Nociception Index) which consists of estimating the sympathetic-parasympathetic balance by a complex analysis of cardiac rhythm variability.

These two types of monitoring could predict which children will require post-operative morphine treatment.

To date, no study has demonstrated the relationship between videopupillometry and postoperative morphine consumption. The average ANI has already been evaluated in children as correlated with FLACC but both monitoring devices have never been compared for a predictive purpose.

The investigators hypothesize that the use of the PPI® (Pain Pupillary Index) scale of Algiscan® and the average ANI measured by the PhysioDoloris® monitor in children still sedated at the end of the intervention could have a prognostic value on post-operative morphine prescription.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

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Intervention / Treatment

Intervention / Treatment

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Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
93

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • France
      • Limoges, France, 87042
        • University Hospital

Participation Criteria

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Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

No older than 7 years (Child)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Any child for whom tonsillectomy is programmed ≥ 2 years and up to 7 years inclusive
  • Consent written and signed by at least one holder of exercise of parental authority

Exclusion Criteria:

  • Eye disease
  • Cardiac pathology
  • Neurological pathology
  • Chronic opioid treatment
  • Any treatment interfering with the autonomic nervous system
  • Any contraindication to NSAIDs

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Other
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: PPI and ANI measurements

The intervention is the nerve stimulation of the ulnar nerve for evaluation / realization of PPI by videopupillometry.

The realization of PPI and ANI measurements is carried out at the end of the surgical procedure, it implies a maintenance of the anesthesia for approximately 5 additional minutes.
Other: Nerve stimulation of the ulnar nerve

The intervention is the nerve stimulation of the ulnar nerve for evaluation / realization of PPI by videopupillometry.

The realization of PPI and ANI measurements is carried out at the end of the surgical procedure, it implies a maintenance of the anesthesia for approximately 5 additional minutes.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Prognostic value of the Pupillary Index Pain ® measured at the end of the surgical intervention
Time Frame: Day 0 (End of the surgery)
Presence or absence of a morphine prescription during the SSPI.
Day 0 (End of the surgery)
Prognostic value of the average Analgesia Nociception Index measured at the end of the surgical intervention
Time Frame: Day 0 (End of the surgery)
Presence or absence of a morphine prescription during the SSPI.
Day 0 (End of the surgery)

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Correlation between Analgesia Nociception Index measured and maximum score obtained at FLACC scale
Time Frame: Day 1 (Leaving the Post-interventional Monitoring Room)
The correlation coefficient of Pearson or Spearman between the Analgesia Nociception Index measured by the PhysioDoloris® monitor at the end of the surgical intervention and the maximum score obtained at the FLACC scale during the stay in the Post-interventional Monitoring Room.
Day 1 (Leaving the Post-interventional Monitoring Room)
Correlation between Pain Pupillary Index measured and maximum score obtained at FLACC scale
Time Frame: Day 1 (Leaving the Post-interventional Monitoring Room)
The correlation coefficient of Pearson or Spearman between the Pupillary Index ® Pain measured by Algiscan at the end of the surgical intervention and the maximum score obtained at the FLACC scale during the stay in the Post-interventional Monitoring Room.
Day 1 (Leaving the Post-interventional Monitoring Room)
Correlation between variation of the pupillary diameter measured and maximum score obtained at FLACC scale
Time Frame: Day 1 (Leaving the Post-interventional Monitoring Room)
The correlation coefficient of Pearson or Spearman between the change in pupillary diameter measured by Algiscan® at the end of the surgical intervention and the maximum score obtained at the FLACC scale during the stay in the Post-interventional Monitoring Room.
Day 1 (Leaving the Post-interventional Monitoring Room)

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
University Hospital, Limoges

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Charles HODLER, PH, University Hospital, Limoges

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
December 20, 2018

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
February 10, 2020

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
February 10, 2020

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
September 24, 2018

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
October 5, 2018

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
October 9, 2018

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
July 30, 2025

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
July 28, 2025

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
July 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 87RC17_0109 (ENIGME)

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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