The Impact of SCN9A Gene Polymorphism on Individual Pain Perception in the General Population

Study Overview
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Brief Summary
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This study was conducted to explore whether the non-synonymous single-nucleotide polymorphisms in SCN9A gene can predict individual basal pain perception and postoperative pain intensity in the general population undergoing upper abdominal surgery. Methods: Patients receiving elective upper abdominal surgery under general anesthesia were recruited into this study. Genotyping of SCN9A was carried out by direct sequencing. The investigators measured their preoperative pressure pain threshold (PPT) and pressure pain tolerance (PTO). The visual analog scale (VAS) was used for pain evaluation at rest during patient-controlled analgesia (PCA) treatment 0 h, 12 h ,24 h and 48h after operation. And the PCA press frequency and drug consumption were recorded.

Detailed Description
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Patients with the following diseases were excluded: known history of chronic pain, psychiatric diseases or communication disorders, diabetes mellitus, severe cardiovascular diseases, kidney or liver diseases with poor hepatic function, alcohol or drug abuse, heavy smoker, pregnancy or at the lactation period.

Official Title
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The Impact of SCN9A Gene Polymorphism on Individual Pain Perception in the General Population

Conditions
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Pain, Surgery

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Aged 20-70 years Receiving elective upper abdominal surgery Anesthesiologists (ASA) physical status I or II Received PCA administration Agreed to participate the research Exclusion Criteria: History of chronic pain Psychiatric diseases Diabetes mellitus Severe cardiovascular diseases Kidney or liver diseases Alcohol or drug abuse Heavy smoker Pregnancy or at lactation period Refused PCA administration Disagree to participate to the research

Ages Eligible for Study
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Minimum Age: 20 Years
Maximum Age: 70 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 |
| --- | --- |
| mutant alleles<br>grouped by SCN9A mutant alleles including 3312T, 1719R, 1150W. | |
| wild-type alleles<br>grouped by SCN9A wild-type alleles including 3312G, 1719C, 1150R. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Opioid Consumption Dose 48h After Operation. |  | 48 hours after the operation | 
| PCA Press Frequency 48h After Operation. |  | 48 hours after the operation | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The Visual Analog Scale 48h After Operation. | The visual analog scale (VAS) is used for pain evaluation at rest during patient-controlled analgesia (PCA) treatment 48h after operation. And the visual analog scale is from 0 to 10 which 0 represent no pain while 10 represent unbearable pain | 48 hours after the operation | 
| Preoperative Pressure Pain Threshold (PPT) | The probe of pressure algometer was positioned perpendicularly to the skin surface of the patient, and the investigator applied continuous pressure at approximately the same rate according to the visual LCD display on the algometer. subjects were asked to say pain when they started to feel pain during the stimulation. The value from the LCD was recorded as the pressure pain threshold. | 12 hours before the operation | 
| Preoperative Pressure Pain Tolerance (PTO) | The probe of pressure algometer was positioned perpendicularly to the skin surface of the patient, and the investigator applied continuous pressure at approximately the same rate according to the visual LCD display on the algometer. subjects were asked to say ok when they started to feel the pain became intolerable during the stimulation. The value from the LCD was recorded as the pressure pain tolerance. | 12 hours before the operation | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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gene polymorphism, SCN9A, pain perception, postoperative pain