Three-level Injection Paravertebral Block vs General Anesthesia in Mastectomy
Status:
Completed
Trial end date:
1969-12-31
Target enrollment:
Participant gender:
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.