The Pectoral Block for Breast Augmentation Surgery

Study Overview
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Brief Summary
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The pectoral block is a recently developed regional anesthetic technique that can be used for the treatment of postoperative pain after breast surgery. Injection of local anesthetic between the major and the minor pectoral muscles is defined as the pectoral (PEC) 1 block. This block has not been well characterized in terms of its blocking effects on motor and sensitive nerves (medial and lateral pectoral nerves and intercostal nerves). This clinical trial is divided into two sections: a volunteer study and a patient study. For the volunteer study, the aim is to assess the sensory territory affected by injection of local anesthetics through a PEC 1 block and to assess motor function in terms of strength of adduction of the affected limb using a dynamometer. In a prospective, randomized, controlled and double blind study, the aim is to assess the postoperative pain relieving properties of the PEC 1 block in patients undergoing bilateral breast augmentation surgery.

Official Title
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The Pectoral Block for Breast Augmentation Surgery: a Volunteers' and Patients' Study.

Conditions
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Pain, Postoperative, Anesthesia; Regional

Intervention / Treatment
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* Procedure: PEC 1 block
* Drug: Bupivacaine with epinephrine
* Drug: Normal saline


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: breast augmentation surgery registration at régie d'assurance maladie du Québec (RAMQ) (social services) Exclusion Criteria: known bleeding disorder anticoagulant intake infection at site of PEC 1 block pregnant or breast-feeding women allergy to bupivacaine chronic pain including fibromyalgia with regular analgesic consumption under recreational drugs or alcohol at doses above canadian recommendations muscle relaxants intake patients already operated for breast augmentation or mastectomy

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 70 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Placebo Comparator: Control group<br>PEC 1 block with injection of 0.4 mL/kg of normal saline under echoguidance. | Procedure: PEC 1 block<br>* Under echoguidance, injection of the substance of interest between the major and minor pectoral muscles.<br>* Other names: pecblock;Drug: Normal saline<br>* Placebo group<br>|
| Active Comparator: Treatment group<br>PEC 1 block with injection of 0.4 mL/kg of 0.25% bupivacaine with 1/400 000 epinephrine under echoguidance. | Procedure: PEC 1 block<br>* Under echoguidance, injection of the substance of interest between the major and minor pectoral muscles.<br>* Other names: pecblock;Drug: Bupivacaine with epinephrine<br>* Treatment group<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Postoperative pain score at rest | Pain score using a verbal numerical scale (0-10) in one breast (bupivacaine) compared to the other breast (placebo) | Within the first 10 min after arrival to the postanesthesia care unit (PACU) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Postoperative pain score on movement | Pain score using a verbal numerical scale (0-10) in one breast (bupivacaine) compared to the other breast (placebo) | Within the first 10 min after arrival to the postanesthesia care unit (PACU) | 
| Postoperative pain score at rest | Pain score using a verbal numerical scale (0-10) in one breast (bupivacaine) compared to the other breast (placebo) | 15 min, 30 min, 60 min, 12h and 24 h after time of arrival in the PACU and immediately after discharge from PACU | 
| Incidence of nausea and/or vomiting | Presence or absence of nausea and/or vomiting | 15 min, 30 min, 60 min, 12h and 24 h after time of arrival in the PACU and immediately after discharge from PACU | 
| Surgical bleeding | Presence or not of surgical bleeding from wounds, drains eventually leading to surgical exploration | After surgery for 24 hours | 
| Hematoma | Presence or absence of hematoma at PEC 1 block injection | After surgery for 24 hours | 
| Postoperative well-being | Analgesic intake | At 24 hours after surgery |