Comparison of Paravertebral Block With General Anesthesia in Patients Undergoing Breast Cancer Surgery

Study Overview
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Brief Summary
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The purpose of this project is to determine if there is a difference between paravertebral block and general anesthesia in terms of time to discharge from the Post-Anesthesia Care Unit and pain level in patients undergoing outpatient breast cancer surgery.

Detailed Description
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The optimal anesthetic technique for breast cancer surgery allows for good postoperative pain relief and rapid discharge. Breast cancer surgery with potential axillary dissection is often performed under general anesthesia due to the potential for poor analgesia with local anesthetic infiltration at the surgical site alone. General anesthesia can be associated with increased post-operative pain, nausea, and delayed discharge when compared to regional anesthesia for breast and other types of procedures (1,2). The paravertebral block is a technique that has been used perioperatively for breast (3,4), thoracic (5), abdominal (6), and hernia surgeries (7). It has also been used for pain control after rib fractures and penetrating trauma (8,9). The paravertebral block is performed by injecting local anesthetic above or below the transverse processes of the vertebral bodies where the spinal nerve roots emerge from the intervertebral foramina. The most common technique is to insert a needle 2.5 centimeters lateral to the spinous process at each level and walk off the transverse process. Injections at one or multiple levels block the somatic and sympathetic innervation to these dermatomes (10). Rare complications of thoracic paravertebral blocks include epidural spread, intrathecal injection, and Horner's Syndrome (1,11,12). One of the most feared complications of the traditional technique is pleural puncture, which has an incidence of 0.64% to 6.7% in the published literature (3,11,13). Ultrasound guidance in regional anesthesia is gaining widespread popularity. This technology provides visualization of key anatomic structures and has been shown to decrease block placement and onset times (14,15) and improve patient comfort (15). Ultrasound-guided blocks are associated with success rates of greater than 90% (15,16). In the thoracic region, ultrasound can be used to identify the vertebral transverse processes, as well as the ribs and the pleura of the lungs (17). In this way, pleural puncture can be avoided during paravertebral block placement. To date there have been no published prospective, randomized trials comparing the multiple injection thoracic paravertebral technique using ultrasound guidance to general anesthesia in breast cancer surgery patients. Our hypothesis is that paravertebral block anesthesia will result in shorter Post Anesthesia Care Unit (PACU) stays and decreased Visual Analog Scale (VAS) scores when compared to general anesthesia in patients undergoing breast cancer surgery. Secondary endpoints will include the need for postoperative opioids and the presence of nausea and/or vomiting.

Official Title
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A Comparison of Ultrasound-assisted Paravertebral Block and General Anesthesia for Outpatient Breast Cancer Surgery, a Prospective Randomized Trial

Conditions
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Breast Cancer

Intervention / Treatment
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* Procedure: Paravertebral Block
* Procedure: General Anesthesia


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Women 18 years of age or older with suspected breast carcinoma scheduled for unilateral lumpectomy or mass excision with sentinel node biopsy and possible axillary dissection. Exclusion Criteria: A diagnosis of chronic pain, regular use of opioid medications, infection at the injection site, allergy to amide local anesthetics, bleeding disorder, contraindication to LMA, and patient refusal.

Ages Eligible for Study
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Minimum Age: 18 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: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Paravertebral Block<br>Patients receiving Paravertebral Block. | Procedure: Paravertebral Block<br>* Sedation will be provided with midazolam and fentanyl. The transverse processes of T1-T6 will be located using ultrasound guidance. The area will be prepped with betadine. At each level, a 21 Gauge, 4-inch Stimuplex needle will be inserted in order to make contact with the transverse process. Once the transverse process has been located, the needle will be walked off the process and inserted 1 cm deep to its inferior border. After negative aspiration, 3 mL of 1.5% mepivacaine with epinephrine 1:200,000 and bicarbonate and 3 mL of 0.5% bupivacaine with epinephrine 1:200,000 will be injected. Sedation will be provided with 50-100 mcg/kg/min of propofol during the surgical procedure. Approximately 20 minutes before the end of the procedure, 4 mg of zofran will be administered.<br>|
| Active Comparator: General Anesthesia<br>Patients receiving General Anesthesia. | Procedure: General Anesthesia<br>* Patients in the general anesthesia group will receive midazolam preoperatively for anxiolysis. Anesthesia will be induced with propofol and fentanyl. An LMA will be inserted and anesthesia maintained with sevoflurane in air and oxygen. 4 mg of zofran will be administered approximately 20 minutes before the end of the surgical procedure. The LMA will be removed and the patient will be transported to the PACU at the conclusion of the surgery.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Time in minutes until the patient is declared ready for discharge from the Post Anesthesia Care Unit (PACU) |  | Until PACU discharge | 
| Visual Analog Scale (VAS) pain scores at 30, 60, 90, and 120 minutes after PACU admission. A VAS score will also be assessed on the first postoperative day. |  | Until PACU discharge and for 24 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The need for postoperative opioids in the PACU and during the first postoperative day will be assessed. |  | 24 hours | 
| Episodes of nausea or vomiting in the PACU and during the first postoperative day will be assessed. |  | 24 hours | 
| Total time spent in the operating room |  | Perioperative | 
| Overall patient satisfaction |  | After hospital discharge | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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breast carcinoma, breast cancer, paravertebral block, comparison of paravertebral block and general anesthesia, ultrasound