Three-level Injection Paravertebral Block vs General Anesthesia in Mastectomy

Summary

The purpose of the study is to investigate if paravertebral block for breast surgery may improve postoperative analgesia and shorten length of hospital stay. Within a prospective clinical trial sixty women (ASA I - III) undergoing unilateral mastectomy surgery with axillary dissection are enrolled. Exclusion criteria are general infection and local infection at the site of planned puncture, anatomic deformities of the thoracic spine, coagulation disorders, allergy against local anesthetics or contrast agents, pregnancy or breast-feeding and BMI ≥ 30 kg/m2.

Patients are randomly assigned to two groups, 30 patients each, by using block of four method. Group I patients receive paravertebral block at spine level Th 4 via catheter; Group II patients will have general anesthesia without nitrous oxide.

Paravertebral block (PVB) will be entirely performed by one person (1st author) with the patient in prone position. In randomly selected patients the catheter localization will be detected by fluoroscopy after injection of 0.5 ml contrast agent. The catheter positioned at about 8 cm from skin level, a mixture of 10 ml bupivacaine 0.5% plus 20 ml lidocaine 2% with adrenaline 1:200,000 will be injected sequentially 10 ml each while withdrawing the catheter 2 cm after the first and again 2 cm after the second injection. Then the catheter will be removed. Low dose intraoperative sedation is provided with IV midazolam 2-3 mg, ketamine 0.5 mg/kg bolus and continuous propofol using target-controlled infusion (TCI) system aiming at effect site concentration (Ce) of 1 - 1.5 mcg/mL to allow spontaneous breathing. In case surgical approach is not tolerated, the regional block is graded insufficient, and it is switched to general anesthesia.

At postoperative care unit (PACU) the pain score using visual rating scale (VRS) from 0 to 10 (worst imaginable pain) is assessed at rest and on movement of the shoulder every 15 minutes until 60 minutes. Analgesia is provided by IV morphine 0.04 mg/kg boluses with a 15-min dosing interval to maintain VRS - score \< 3. Time to first analgesic demand and 24-hr analgesics consumption is recorded as well as postoperative nausea and vomiting (PONV). Complications are recorded including those related to the paravertebral block, such as Horner's syndrome, epidural spreading, hypotension that is not related to another. Patients will be checked 6, 12, and 24hr postoperatively for adverse effects, pain scores, and satisfaction scores.

Conditions

• Radical Mastectomy

Interventions

PROCEDURE

paravertebral block

catheter with 3-level-injection

DRUG

fentanyl, propofol, atracurium

endotracheal intubation

DRUG

lidocaine , adrenaline, ketamine bolus, midazolam

a mixture of 10 ml bupivacaine 0.5% plus 20 ml lidocaine 2% with adrenaline 1:200,000, ketamine bolus 0.5 mg/kg, midazolam 2-3 mg and continuous propofol using target-controlled infusion (TCI) system aiming at effect site concentration (Ce) of 1-1.5 mcg/mL

DEVICE

catheter with 3-level-injection

DRUG

sevoflurane and 50% oxygen in air

Sponsors & Collaborators

• Ramathibodi Hospital

  lead OTHER

Principal Investigators

• Benno von Bormann, MD · Mahidol University Bangkok

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

SINGLE

Model

PARALLEL

Eligibility

Min Age

18 Years

Max Age

90 Years

Sex

FEMALE

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2013-10-31

Primary Completion

2014-03-31

Countries

• Thailand

Study Locations