Pupillary Reflex Measurement to Guide Intraoperative Analgesia During Laparoscopic Surgery

Study Overview
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Brief Summary
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The purpose of this study is to determine whether analgesia guided by pupillary reflex during laparoscopic surgery is effective in opioid sparing (intraoperative remifentanil and postoperative morphine).This is a prospective, randomized, controlled study performed in two centers.

Detailed Description
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For now, intraoperative analgesia remains hard to assess in the absence of reliable and validated analgesia monitor. The analysis of pupillary reflex is a new tool to assess analgesia during the intraoperative and postoperative period. During laparoscopic surgery, carbon dioxide insufflation that produce pneumoperitoneum may induce hemodynamics events such as tachycardia or hypertension. These events may be misleading or confusing. Actually, these events are mainly considered as insufficient analgesia. Thus, anesthesiologists deepen analgesia and/or anesthesia by increasing concentration of anesthetics or opioids. These inappropriate actions may induce hypotension and/or bradycardia especially in elderly patients. On the contrary, insufficient analgesia may exist in hypovolemic patients or in patients with neuromuscular blocking agents.

Official Title
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Usefulness of Pupillary Reflex on Remifentanil and Morphine Consumption During Laparoscopic Surgery. A Bicentric, Prospective, Randomized, Controlled Trial.

Conditions
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Scheduled Laparoscopic Surgery

Intervention / Treatment
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* Device: Pupillometry guided analgesia (PP)
* Drug: Tailored remifentanil controlled infusion
* Drug: Tailored antihypertensive drug administration


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: American Society of Anesthesiologists status 1 to 4 Scheduled laparoscopic surgery Standardized anesthesia (TCI) Social security affiliation Exclusion Criteria: Age < 18 yrs old Emergency BMI ≥ 35 kg.m-2 Refusal of consent History of ocular pathology Intake of: metoclopramide, droperidol, opioids or substitutive therapies Patient with chronic pain Neurologic impairments Neuropathic pain Drug or alcohol abuse

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

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: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Pupillometry guided analgesia (PP)<br>Analgesia is guided by pupillary reflex. The anesthesiologist in charge must adjust the peroperative remifentanil dose (Target controlled infusion) during surgery according to the algorithm proposed. Administration of antihypertensive drugs or vasopressors is also guided. | Device: Pupillometry guided analgesia (PP)<br>* Analgesia is guided by pupillary reflex provided by the pupillometer (AlgiScan). The anesthesiologist in charge must adjust the peroperative remifentanil dose (Target controlled infusion) during surgery according to the algorithm proposed (Tailored remifentanil controlled infusion). Administration of antihypertensive drugs or vasopressors is also guided.<br>* Other names: Pupillometer;Drug: Tailored remifentanil controlled infusion<br>* The anesthesiologist in charge must adjust the peroperative remifentanil dose (Target controlled infusion) during surgery according to the algorithm proposed<br>* Other names: TCI;Drug: Tailored antihypertensive drug administration<br>* Administration of antihypertensive drugs or vasopressors is guided by the results of the pupillary reflex.<br>* Other names: Urapidil;|
| No Intervention: Standard practice (ST)<br>Anesthesia and analgesia is left to the discretion of the anesthesiologist in charge. The anesthesiologist is blinded to the results of pupillometry. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Peroperative Remifentanil consumption |  | From the start of anesthesia to the end of surgery (<10 hours) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of hemodynamic events (hypertension, hypotension, tachycardia or bradycardia...) |  | From the start of anesthesia to the end of surgery (<10 hours) | 
| Use of antihypertensive agents or vasopressors |  | From the start of anesthesia to the end of surgery (<10 hours) | 
| Volume of fluid replacement |  | From the start of anesthesia to the end of surgery (<10 hours) | 
| Pain scores | Using verbal rating scale | In the immediate postoperative period (<4 hours) | 
| Incidence of postoperative nausea and vomiting (PONV) |  | In the immediate postoperative period (<4 hours) | 
| Time from extubation between the end of surgery and PACU admission |  | In the immediate postoperative period (<4 hours) | 
| Length of stay in PACU |  | From PACU admission to an ALDRETE score of 10 (< 4 hours) | 
| Immediate postoperative morphine consumption |  | During postanesthetic care unit (PACU) stay (<4 hours) | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Pupillometry, Pupillary reflex, Analgesia, Laparoscopic surgery, Total intravenous anesthesia, Target controlled infusion