Gradual Withdrawal of Remifentanil Infusion Reduced Postoperative Pain and Opioid Requirement During Breast Surgery

Study Overview
=================
Brief Summary
-----------------
Although remifentanil provides profound analgesia during operation, postoperative occurrence of hyperalgesia and tolerance after remifentanil administration could be a challenge to the postoperative pain control. Evaluation of analgesia and anti-nociception during anesthesia is still a challenging issue. Surgical Pleth Index (SPI) is a non-invasive and simple access tool used to monitor autonomous nervous system during anesthesia. This technique is based on photoplethysmographic wave and heart beat analysis. SPI values range between 0 (no stress) and 100 (high stress level). The purpose of this study was to determine the appropriate use of Remifentanil for pain control in patients with SPI.

Detailed Description
-----------------
Patients were randomized into either SPI-guided analgesia or standard practice (Control). In both groups, anesthesia was maintained with total intravenous anaesthesia(TIVA) to keep bispectral index values between 40 and 60. In the Remifentanil gradual reduction group (test group), 20 minutes before the end of the operation, remifentanil was gradually decreased by 25% every 5 minutes. The control group stopped remifentanil 10 minutes before the end of the operation. SPI was recorded before the intubation, after the intubation, directly before the end of surgery. The number of unwanted somatic events, hemodynamics, Patient-controlled analgesia(PCA) consumption, narcotic analgesics consumption, and recovery times were recorded.

Official Title
-----------------
Gradual Withdrawal of Remifentanil Infusion Reduced Postoperative Pain and Opioid Requirement During Breast Surgery

Conditions
-----------------
Pain, Postoperative

Intervention / Treatment
-----------------
* Drug: Remifentanil


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Patients who received the breast conserving surgery Exclusion Criteria: Patients with arrhythmia who have poor SPI measurement When the patient refused Patients with decreased renal function of Cr> 2 Surgery for more than 3 hours, surgery expected to bleed more than 500 ml

Ages Eligible for Study
-----------------
Minimum Age: 20 Years
Maximum Age: 80 Years

Sexes Eligible for Study
-----------------
Female

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

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

Design Details

Primary Purpose: Supportive Care
Allocation: Randomized
Intervention Model: Crossover Assignment
Interventional Model Description: In this study, remifentanil gradually withdrawal goup (test group) and remifentanil immediately stop group (control group) were divided into two groups. In the Remifentanil gradual reduction group (test group), 20 minutes before the end of the operation, remifentanil was gradually decreased by 25% every 5 minutes. The control group stopped remifentanil 10 minutes before the end of the operation.
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Remifentanil gradually withdrawal group<br>20 minutes before the end of the operation, remifentanil was gradually decreased by 25% every 5 minutes. | Drug: Remifentanil<br>* Remifentanil is a potent, short-acting synthetic opioid analgesic drug. It is given to patients during surgery to relieve pain and as an adjunct to an anesthetic.<br>|
| Active Comparator: Remifentanil immediately stop group<br>The control group stopped remifentanil 10 minutes before the end of the operation. | Drug: Remifentanil<br>* Remifentanil is a potent, short-acting synthetic opioid analgesic drug. It is given to patients during surgery to relieve pain and as an adjunct to an anesthetic.<br>|

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

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Numeric Rating Scale(NRS) | The difference of postoperative highest pain score (NRS) between two groups | postoperative 1 hour | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| SPI | The difference of Surgical Pleth Index between two groups | intraoperative (after the laryngeal mask airway) | 
| SPI | The difference of Surgical Pleth Index between two groups | intraoperative (after the incision) | 
| analgesics consumption | The difference of analgesics consumption between two groups | during post-anesthesia care unit | 
| analgesics consumption | The difference of analgesics consumption between two groups | up to postoperative 48hours | 
| nausea & vomiting | The difference of nausea and vomiting between two groups | postoperative 1 hour | 
| Numeric Rating Scale(NRS) | The difference of highest postoperative pain score (NRS) between two groups | during postoperative 48hours | 
| the duration of eye opening | the duration of eye opening after stoping propofol | end of surgery | 
| intraoperative remifentanil consumption | the dose of intraoperative remifentanil according to postoperative pain | intraoperative |