ANI-guided Intraoperative Analgesia vs Conventional Intraoperative Analgesia

Study Overview
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Brief Summary
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This study evaluates the effects of Analgesia Nociception Index (ANI)-guided intraoperative analgesia on postoperative pain in patients undergoing open gynecologic surgery.

Detailed Description
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Postoperative pain is one of the most common postoperative complications and is significantly associated with patient's quality of recovery. Analgesia Nociception Index (ANI) is known to analyze the high frequency component of heart rate variability in relation to respiratory frequency, providing the objective information on the degree of pain. However, most previous studies conducted by using ANI were observational studies or small-sized randomized controlled studies. In the present study, the investigators aimed to evaluate the effects of ANI-guided intraoperative analgesia on moderate-to-severe postoperative pain by performing randomized controlled study.

Official Title
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Effects of Analgesia Nociception Index (ANI)-Guided Intraoperative Analgesia on Postoperative Pain: a Randomized Controlled Study

Conditions
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Postoperative Pain, Analgesia, Surgery

Intervention / Treatment
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* Procedure: ANI-guided intraoperative analgesia
* Procedure: Conventional intraoperative analgesia


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age ≥ 18 Elective open gynecological surgery American Society of Anaesthesiologists physical status classification 1-3 Exclusion Criteria: Laparoscopic surgery or robot-assisted surgery Patients who had analgesic agents, anti-psychotic agents, anticonvulsants which were related to chronic pain Patients who had hypersensitivity to analgesic agents or medications related anesthesia. Patients who were required to have mechanical ventilation after surgery Patients who had arrhythmia Patients who transferred to the surgical intensive care unit immediately after surgery Pregnancy

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 80 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: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: ANI-guided intraoperative analgesia<br>Intraoperative analgesia is performed by controlling the effect-site concentration of remifentanil to maintain 50-70 of ANI index. | Procedure: ANI-guided intraoperative analgesia<br>* Intraoperative analgesia is performed by controlling the effect-site concentration of remifentanil to maintain 50-70 of ANI.<br>|
| Active Comparator: Conventional intraoperative analgesia<br>Intraoperative analgesia is performed by controlling the effect-site concentration of remifentanil at the discretion of attending anesthesiologists based on hemodynamic parameters. | Procedure: Conventional intraoperative analgesia<br>* Intraoperative analgesia is performed by controlling the effect-site concentration of remifentanil at the discretion of attending anesthesiologists based on hemodynamic parameters.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| the incidence of moderate-to-severe postoperative pain | the incidence of moderate-to-severe postoperative pain is defined as a case in which pain with numeric rating scale (NRS) of 5 or more is reported during stays in the postanesthesia care unit. Pain assessment is performed two times during stays in the postanesthesia care unit. | during 1 hour of stay in the postanesthesia care unit | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| the amount of intraoperative remifentanil | the amount of intraoperative remifentanil used during anesthesia | intraoperative | 
| Quality of Recovery-15 (QoR-15) score | QoR-15 questionnaire is recorded by an investigator. QoR-15 questionnaire has minimum score of 0 and maximum score of 150, and higher score indicates the better quality of recovery. | at postoperative 24 hour | 
| the incidence of postoperative nausea and vomiting | the incidence of postoperative nausea and vomiting is recorded by an investigator | at postoperative 1 hour, 24 hour, 72 hour | 
| 11-pointed NRS pain score | 11-pointed NRS pain score is measured at both resting state and movement. 11-pointed NRS pain score has minimum score of 0 and maximum score of 10, and higher score indicates the higher severity of pain. | at postoperative 24 hour |