Single Versus Multiple Injection Ultrasound Guided Paravertebral Blocks

Study Overview
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Brief Summary
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Paravertebral block (PVB) has been shown to provide excellent analgesia for major breast surgeries resulting in reduced narcotic consumption, reduced nausea, improved quality of recovery, reduced chronic pain and possibly reduced metastasis with breast cancer. Traditionally, PVB is done by multiple injections below T1-T5 transverse processes. With multiple injections, the risk is increased for a pleural, an intraneural, and/or an intravascular injection. Recently, ultrasonography is being used to facilitate PVB. The use of ultrasound imaging enables real-time needle visualization during the procedure. This may improve efficacy and reduce the chances of complication like pneumothorax. Currently, there are no data comparing ultrasound-guided single injection technique with multiple injections technique with regards to extent of spread for PVB. Our objective is to investigate the extent of dermatomal spread of PVB when equal volumes of local anesthetic are injected at one versus five paravertebral sites for patients undergoing major breast surgery. In addition, the investigators wish to compare the performance time and duration of analgesia. Methodology: After local REB approval, 72 patients undergoing a unilateral mastectomy with or without axillary node dissection will be randomized to receive either single or multiple injections PVB. The PVB will be performed in prone position under real-time ultrasound guidance using a para-sagittal approach.The patients in single injection group will receive single injection PVB at T3-T4 level with 25 ml of 0.5% ropivacaine and four subcutaneous sham injections. Patients in the multiple injection group will receive five injections of PVB from T1 to T5 level. 5 ml of 0.5% ropivacaine will be injected at each level. Pleural drift will be used as a sign of correct needle tip location and local anaesthetic spread. The pinprick method will be used to assess the extent of dermatomal blockade, 20 minutes following the completion of procedure. All patients will receive a standardized general anesthesia for the surgery. Any adverse events including pneumothorax, epidural spread, LA toxicity/seizure, total spinal, will be recorded.

Official Title
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Randomized Prospective Study to Evaluate Efficacy and Safety of Single Versus Multiple Injection Ultrasound Guided Paravertebral Blocks for Breast Surgery

Conditions
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Breast Neoplasms, Anesthesia

Intervention / Treatment
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* Procedure: Single injection paravertebral block
* Procedure: Multiple injection paravertebral blocks


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Females, age 18 to 80 years, scheduled to receive unilateral mastectomy surgery, with or without axillary node dissection Able to give informed consent Able to cooperate with study process Availability of home telephone. Exclusion Criteria: Patient refusal or lack of informed consent allergy to local anesthetic and other medications used in the study Bilateral mastectomies Coexisting hematological disorder or with deranged coagulation parameters Pre-existing major organ dysfunction such as hepatic and renal failure Significant thoracic kyphoscoliosis History of previous thoracic surgery.

Ages Eligible for Study
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Minimum Age: 18 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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Design Details

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


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Multiple injection paravertebral blocks<br>Patients in this group will receive five injections of paravertebral blocks from T1 to T5 level. 5 ml of 0.5% ropivacaine was injected at each level. | Procedure: Multiple injection paravertebral blocks<br>* Patients in the multiple injection group will receive five injections of paravertebral blocks from T1 to T5 level. 5 ml of 0.5% ropivacaine was injected at each level.<br>|
| Experimental: Single injection paravertebral block<br>Patients in single injection group will receive single injection paravertebral blocks at T3-T4 level with 25 ml of 0.5% ropivacaine and four subcutaneous sham injections. | Procedure: Single injection paravertebral block<br>* The patients in single injection group will receive single injection paravertebral block at T3-T4 level with 25 ml of 0.5% ropivacaine and four subcutaneous sham injections<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Sensory dermatomal spread | 20 minutes after block performance | 20 minutes | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Time to performance of procedure |  | Duration of procedure | 
| Cephalic and caudal dermatomal spread |  | 20 minutes after block performance | 
| Incidence of complication | Follow-up phone call | 24 hours | 
| VAS pain scores in PACU | During PACU stay | 6 hours | 
| Duration of self-reported numbness at the surgical site | At follow-up phone call | 24 hours |