Intraoperative Nociception and Postoperative Pain

Study Overview
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Brief Summary
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If the individual patient's pain is assessed and the amount of analgesic needed after surgery is predicted, appropriate injection of pain control and excessive injection of narcotic analgesic can be prevented. Therefore, investigators try to evaluate the relation intraoperative nociception response with postoperative pain score. In similar anesthetic depth(End tidal sevoflurane 3%) , changes of surgical pleth index values for stimulus of skin incision are thought to reflect the individual nociception characteristics.

Detailed Description
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Patients who undergoing upper abdominal laparotomy surgery usually experience severe postoperative pain. Previous studies were reported that preoperative pain, young age, high-dose remifentanil, and depression were associated with severe postoperative pain. However, anesthesia-related studies were either retrospective studies or injected with anesthetic agents in excess of clinical doses to differentiate between groups. There is no objective indicator for prediction severe postoperative pain.The purpose of this study was to investigate the relationship between intraoperative pain response and postoperative pain on standardized surveillance devices. To maintain the depth of anesthesia, an EEG monitoring device bispectral index (BIS) is used. Also, surgical pleth index (SPI, GE healthcare, Freiburg, Germany) is a noninvasive pain-analgesia balance monitoring device that is commercially available to evaluate the state of pain during general anesthesia. SPI = 100- (0.3 * heart beat interval + 0.7 * photoplethysmographic pulse wave amplitude) is automatically and continuously calculated from the waveform of peripheral oxygen saturation. In similar anesthetic depth(End tidal sevoflurane 3%) , changes of SPI values for stimulus of skin incision are thought to reflect the individual nociception characteristics. The investigators hypothesized the higher analgesics consumption can predict with high SPI response following incisional stimuli. Thus, investigators try to evaluate the comparison of two groups ( high fentanyl consumption group vs. low fentanyl consumption group) with intraoperative SPI value (incision and before aurosal) and hemodynamic parameters under End tidal sevoflurane 3%(anesthesia depth, hemodynamically stable and appropriate anesthetic depth based on previous studies were confirmed at the time of skin incision). And the characteristics and emotional status of patients in two groups are compared.

Official Title
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the Prediction of Postoperative Pain With Surgical Incision Stimulation in the Patients Undergoing Gastrectomy

Conditions
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Pain, Postoperative, Nociceptive Pain, Analgesics

Intervention / Treatment
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* Device: SPI group


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: -undergoing laparotomy gastrectomy Exclusion Criteria: cardiac arrythmia allergic history for drugs renal failure (Cr> 1.5 mg/dl)

Ages Eligible for Study
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Minimum Age: 20 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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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| SPI group<br>All patients who received the liver resection surgery will receive surgical pleth index | Device: SPI group<br>* All patients applied surgical pleth index at the time of surgical incision, under End tidal Sevoflurane 3%<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The requirement of postoperative analgesics for postoperative 24 hours | The requirement of postoperative analgesics for postoperative 24 hours (opioid conversion to fentanyl dose mcg) | postoperative 24 hour | 
| The immediate postoperative pain score | The numeric rating pain score, no pain=0   worst pain=10 | postoperative 24 hour | 
| intraoperative nociception score (surgical pleth index) | under End tidal sevoflurane 3%, surgical pleth index score following surgical incision | intraoperative at the time of skin incision | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The correlation of requirement of summed postoperative analgesics and intraoperative nociception score | The consumption of analgesics (opioid conversion to fentanyl dose mcg) and intraoperative surgical pleth index value | postoperative 1 hour | 
| The correlation of highest postoperative pain score and intraoperative nociception score | The postoperative pain score (numeric rating pain score, no pain=0  worst pain=10)and intraoperative surgical pleth index score | postoperative 1 hour |