Estimation of Pain During Epidural Analgesia During Labor

Study Overview
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Brief Summary
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Epidural regional anesthesia is a technique to eliminate or lessen pain during obstetric labor and childbirth. It consists in establishing a catheter into the epidural space and to block the transmission of pain sensations by injecting a local anesthetic and an opioid. In 10-25% of cases the epidural does not give perfect results, causing it to test its effectiveness, which is mainly done by questioning the patient on mitigation or disappearance of pain. This collaboration of patients is sometimes limited in our care structure by the inability to assess or express the pain, mainly due to cultural differences or language barriers, which can represent up to 15% of women in our institution. This led to develop objective measures of pain techniques used at the bedside. Pupil diameter (PD) varies under the double influence of sympathetic system (Σ), dilator of the pupil, and parasympathetic system (pΣ). The PD increases in response to painful stimulation, in proportion to the intensity of the nociceptive stimulus. This variation of PD has been proposed as a means of evaluation of pain in patients under general anesthesia, but has been little studied in conscious subjects. There are other permanent changes in the PD, due to constant interaction between Σ and pΣ systems. Few data have been published to date on this PD variability (PDV).

Official Title
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Estimation of Pain During Epidural Analgesia During Labor - a Monocentric Study

Conditions
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Labor, Obstetric, Pain

Intervention / Treatment
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* Device: Portable video pupillometer


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Obstetrical Labor Able to rate their pain using VAS dilatation of the cervix under 6 centimeters Written consent Exclusion Criteria: - Not having a anesthesia consultation during the 48 hours before delivery With a contra-indication for an epidural To which an incident occurred during a previous epidural using a medication used in the study Operated a unilateral or bilateral ocular surgery modifying the possibilities of variation of pupil diameter general anesthesia in the seven days preceding delivery Carry a pacemaker or heart grafted Having Parkinson's disease history, insulin or non-insulin diabetes or chronic alcoholism Having cardiac arrhythmia (atrial fibrillation or frequent extrasystoles) Treated for hypertension by receptor antagonists of angiotensin type 2 anti-arrhythmic treatment or blocker, Refusing to participate in the study With a contra-indication for the use of ropivacaine and sufentanil.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 45 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: Prevention
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Patients<br>Pain assess by : Visual Analogic Scale (VAS). Portable video pupillometer | Device: Portable video pupillometer<br>* Portable video pupillometer measures pupil diameter (PD) in patient during obstetrical labor<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Pupil diameter variability | Compare Pupil Diameter Variability (PDV) measured before Epidural regional anesthesia and after Epidural regional anesthesia. PDV is aera under the curve of Pupil Diameter from start of the contraction (baseline) to time to peak of the contraction. | From baseline to fifteen minutes after start of Epidural regional anesthesia | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| pupil diameter | Compare the Pupil Diameter measured five seconds after time to peak of contraction before Epidural regional anesthesia and after Epidural regional anesthesia | From baseline to fifteen minutes after start of Epidural regional anesthesia | 
| Visual Analogic Scale (VAS) | Compare the VAS measured at the end of contraction before Epidural regional anesthesia and after Epidural regional anesthesia. | From baseline to fifteen minutes after start of Epidural regional anesthesia | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Labor, Obstetric, pain, pupil diameter, Visual Analogic Scale (VAS)