A Comparison of Local Infiltration Analgesia and Pecs Block for Analgesia in Mastectomy With Axillary Dissection - an Equivalence Study

Study Overview
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Brief Summary
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The investigators aim to compare the quality of pain relief provided by local infiltration analgesia delivered by surgeon and Pecs block delivered by anaesthetist under ultrasound guidance for patients undergoing mastectomy with axillary dissection.

Detailed Description
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Total breast removal with armpit dissection may be a painful surgery. Pectoral nerve block (Pecs block) is common pain relief method used to reduce pain after breast surgery. The Pecs block is a pain relief method technique at targeted body part. The Pecs block numbs nerves which supply sensation to the upper chest wall, armpit and upper arm. This procedure is only possible under ultrasound guidance and is carried out by the anaesthetist (medical specialist who administers anaesthetics) after patients are put under general anaesthesia. Despite the advantages of Pecs block in pain management, this method is not always available to all patients due to various reasons. These reasons include the availability of ultrasound machine to facilitate the method, presence of anaesthetist to carry out the procedure and additional time required to perform this method in the operating theatre. Another method has been modified by our surgeons (medical specialist who performs surgery, a different specialty from anaesthetist) to achieve pain relief among patients undergoing breast removal surgery. This method is called local infiltration analgesia (LIA). The pain control is achieved by having the surgeons to deliver a pain control drug surgically during the breast removal operation. LIA could be a good pain control alternative when a Pecs block could not be performed. The investigators hope to compare the quality of pain relief provided by local infiltration analgesia delivered by surgeon and Pecs block delivered by anaesthetist under ultrasound guidance. The investigators hope to show that LIA delivered by surgeon is as effective as Pecs block in patients undergoing mastectomy with axillary dissection.

Official Title
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A Comparison of Local Infiltration Analgesia and Pecs Block for Analgesia in Mastectomy With Axillary Dissection - an Equivalence Study

Conditions
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Mastectomy; Lymphedema, Local Infiltration, Anesthesia, Local, Block

Intervention / Treatment
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* Procedure: PECs Block
* Procedure: Local infiltration


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age above 21 years old Able to give consent Body weight > 50kg Exclusion Criteria: Patient's refusal and inability to give consent Allergy or contraindicated to local anaesthetics, paracetamol, NSAIDS or opioids Background history of chronic pain Bilateral procedures

Ages Eligible for Study
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Minimum Age: 21 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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Design Details

Primary Purpose: Supportive Care
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: Randomised Controlled
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: PECs Block<br>Total local anaesthetic dose: 30ml ropivacaine 0.5% •Pecs block will be performed by anaesthetist using ultrasound guidance in plane approach: 10ml ropivacaine 0.5% will be delivered at the plane between pectoralis major and pectoralis minor, another 20ml ropivacaine 0.5% will be delivered in the plane between the pectoralis minor and serratus anterior muscles at the level of the third and fourth ribs | Procedure: PECs Block<br>* Regional Anaesthesia Technique ie Pectoralis Nerve Block under ultrasound guidance<br>|
| Placebo Comparator: Local Infiltration<br>LIA will be performed by surgeon during the operation. The upper skin flap will be raised in the standard manner for mastectomy. The lateral border of the major pectoralis muscle will then be visualised. A volume of 10 ml ropivacaine 0.5% will be delivered between the inter-fascial planes of the pectoral muscles. The lower skin flap will then be raised in the standard manner for mastectomy and the breast is raised off the pectoralis muscle exposing the serratus anterior muscle. A volume of 20 ml ropivacaine 0.5% will be delivered between the muscle planes of the serratus anterior and pectoralis minor muscles. | Procedure: Local infiltration<br>* LIA will be performed by surgeon during the operation. The upper skin flap will be raised in the standard manner for mastectomy. The lateral border of the major pectoralis muscle will then be visualised. A volume of 10 ml ropivacaine 0.5% will be delivered between the inter-fascial planes of the pectoral muscles. The lower skin flap will then be raised in the standard manner for mastectomy and the breast is raised off the pectoralis muscle exposing the serratus anterior muscle. A volume of 20 ml ropivacaine 0.5% will be delivered between the muscle planes of the serratus anterior and pectoralis minor muscles.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Total morphine consumption in 24 hour after surgery | Total morphine consumption in 24 hour after surgery | 24 hour | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Duration of analgesia | time to first rescue analgesia after administration of block | 24 hours | 
| Postoperative pain score. | Post op pain score will be assessed using a visual analogue scale (VAS, 0-10; 0 = no pain and 10 = worst imaginable pain). The vital signs and pain score will be recorded at 0, 0.5, 1, 2, 4, 6, 8, 12, and 24 h after surgery by the attending staff nurses blinded to the group allocation | 24 hours | 
| Adverse Effects | Any adverse effects will be recorded (such as hypotension, respiratory depression, pruritus, shivering and urinary retention) | 24 hours | 
| Postoperative nausea vomiting (PONV) | Postoperative nausea vomiting (PONV) | 24 hours | 
| Intraoperative analgesia | total usage of IV Fentanyl intraoperatively | 24 hours | 
| Operative time | duration of surgery | 24 hrs | 
| Block performance time | time from needle insertion until needle exit from the skin | 24 hours | 
| Block related complications | pneumothorax | 24 hours | 
| Block related complications | vascular puncture | 24 hours | 
| Block related complications | local anaesthetic toxicity | 24 hours | 
| Post-operative complications | Bleeding | 24 hours | 
| Post-operative complications | Wound infection | 24 hours |