Evaluation And Risk Assessment For Persistent Postsurgical Pain After Breast Surgery

Study Overview
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Brief Summary
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Pre-existing pain and severe postoperative pain are predictors of persistent pain after surgery, but a complete understanding on the development of persistent pain is still lacking. The study aims to identify clinically relevant and genetic risk factors for persistent postsurgical pain that can be reliably distinguished statistically.

Detailed Description
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The study will focus on: (i) risk factors representing biopsychosocial processes that influence chronic pain, such as pain and psychological vulnerability; (ii) genetic factors relating to mechanistic pathways to persistent pain generation. Patients will be recruited from those undergoing breast cancer surgery at the mentioned site. Pain and anxiety assessment will be conducted via visual analogue scoring, mechanical temporal summation assessment and a series of questionnaires. After the surgery, all patients will be given appropriate analgesia, and the pain score and analgesia usage will be recorded. Phone survey will be conducted 4 and 6 months, respectively, after surgery to determine the outcomes.

Official Title
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Evaluation And Risk Assessment For Persistent Postsurgical Pain After Breast Surgery: A Prospective Cohort Study (Breast CAncer Surgery Postsurgical Pain)

Conditions
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Breast Cancer, Chronic Pain, Acute Pain, Depression, Anxiety

Intervention / Treatment
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* Other: Questionnaires
* Other: Mechanical Temporal Summation assessment
* Other: Pain threshold assessment


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Aged between 21 - 80 year old; Healthy and/or have systemic medical conditions as reviewed by anaesthetist for surgery (ASA 1-3); Undergoing breast cancer surgery. Exclusion Criteria: History of intravenous drug or opioid abuse; Current chronic daily treatment with corticosteroids (excluding inhaled steroids); Previous history of chronic pain syndrome; Obstetric patients.

Ages Eligible for Study
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Minimum Age: 21 Years
Maximum Age: 80 Years

Sexes Eligible for Study
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Female

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 |
| --- | --- |
| Persistent post surgical pain (PPSP)<br>Questionnaires, Mechanical Temporal Summation assessment and pain threshold assessment will be assigned to patient. Within this cohort, some patients will have high pain score recorded (persistent pain) during the follow-up evaluations at 4 and 6 months. | Other: Questionnaires<br>* Questionnaires including Pain catastrophizing scale (PCS), Central Sensitisation Inventory (CSI), Coping Strategies Questionnaire-Revised (CSQ-R), Brief Symptom Inventory-18 (BSI-18), Perceived Stress Scale (PSS), EQ-5D-3L and Eysenck Personality Questionnaire (EPQ) will be administered to the patient.<br>Other: Mechanical Temporal Summation assessment<br>* A 180 gram von Frey filament is applied on the subject's forearm. Patient will then be asked to rate the pinprick pain score on a verbal rating scale, 0-100. Following this, 10 consecutive touches at random locations are applied with a 1 second interstimulus interval and within a 1 cm diameter circle. The patient will then be asked to rate the 10th pain score (0-100). The Mechanical Temporal Summation Score is obtained by the difference between the 11th pain score and the 1st pain score. If the score is greater than zero, the patient is implied to have presence of Mechanical Temporal Summation.<br>* Other names: MTS;Other: Pain threshold assessment<br>* Pressure is applied 90 degree straight down force on the subject's right/left centre of the trapezius muscle using an algometer, with a speed of pressure   1kgf/s. The above procedure is then repeated 3 times at each site (left/right) which is indicated on the pressure mark with each time having the reading recorded. When patient shows no response ≥ 6kgf, the threshold is recorded as 6kgf. The patient upon feeling pain will say stop or raise the hand to terminate the test. The mean value is obtained by averaging the readings and will then be recorded as the threshold estimate.<br>* Other names: Pressure pain;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Persistent pain at 4 months after surgery | Persistent pain is defined as having one of the below criteria at 4 months after surgery: i) having pain score at rest (Numeric Rating Scale 0 to 100) of 30 or more; or ii) having pain score on movement (Numeric Rating Scale 0 to 100) of 30 or more; or iii) or yes to one of the seven questions on the presence of pain in daily life activities (mood, walking, carrying heavy loads, work, relations with people, sleep, enjoyment of life) | 4 months after surgery | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Persistent pain at 6 months after surgery | Persistent pain is defined as having one of the below criteria at 4 months after surgery: i) having pain score at rest (Numeric Rating Scale 0 to 100) of 30 or more; or ii) having pain score on movement (Numeric Rating Scale 0 to 100) of 30 or more; or iii) or yes to one of the seven questions on the presence of pain in daily life activities (mood, walking, carrying heavy loads, work, relations with people, sleep, enjoyment of life) | 6 months after surgery | 
| Maximum Acute post-operative pain score | The maximum number of patient-reported post-operative pain score (Numeric Rating Scale 0 to 100) at 0 - 72 hours | Up to 3 days after surgery | 
| Opioid consumption | The total opioid consumption (morphine/ fentanyl/ hydromorphone/ oxycodone/ hydrocodone etc) throughout the 72 hours. The opioid consumption will be converted using oral morphine equivalent (OME) conversion calculations. | Up to 3 days after surgery | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Breast cancer, Chronic pain, Acute Pain, Depression, Anxiety