Single-Injection Paravertebral Block Before General Anesthesia Enhances Analgesia After Breast Cancer Surgery With and Without Associated Lymph Node Biopsy

Abstract

Paravertebral block (PVB) seems to decrease postoperative pain and postoperative nausea and vomiting (PONV) after breast surgery, but the studies have not been placebo controlled. We studied 60 patients scheduled for breast cancer surgery randomly given single-injection PVB at T3 with bupivacaine 5 mg/mL (1.5 mg/kg) or saline before general anesthesia. The patient and attending investigators were blinded; the PVB or the sham block was performed behind a curtain by an anesthesiologist not involved in the study. The patients given PVB with bupivacaine needed 40% less IV opioid medication (primary outcome variable) in the postanesthesia care unit, had a longer latency to the first opioid dose, and had less pain at rest after 24 h than the control patients (P < 0.01). They also had less PONV in the postanesthesia care unit (P < 0.05), were less sedated until 90 min (P < 0.05), and performed better in the digit symbol substitution test at 90 min and the ocular coordination test 60-120 min after surgery (P < 0.05). The average peak bupivacaine plasma concentration was 750 ng/mL. One patient had bilateral convulsions immediately after bupivacaine injection. We conclude that PVB before general anesthesia for breast cancer surgery reduced postoperative pain, opioid consumption, and occurrence of PONV and improved recovery from anesthesia.

Thoracic paravertebral regional anesthesia improves analgesia after breast cancer surgery: a randomized controlled multicentre clinical trial

“…Only three previous studies evaluated use of volatile anesthetics, and the results were inconsistent. 15 As might be expected, previous small studies generally overestimated treatment effect, with some reporting differences exceeding three points on an 11-point scale. 24 Combining all studies, the overall pain benefit was a reduction by more than 2, an amount which was highly statistically significant but probably also reflects a clinically important reduction in discomfort.…”

“…15,29 Two additional recent trials 32,33 were identified, which were included in our meta-analysis along with our current result.…”

“…4 and 5. For worst pain score in the immediate two postoperative hours, the recent relevant meta-analysis 23 contained five eligible trials [24][25][26][27][28] evaluating paravertebral anesthesia as a single technique vs GA and five eligible trials 14,15,[29][30][31] evaluating the combination of paravertebral analgesia and GA vs GA alone. One additional recent trial 32 was identified and included in our meta-analysis along with our current results.…”

“…14,15,[24][25][26][27][28][29][30][31][32] Only five published trials 15,25,29,32,33 with only 262 patients in total evaluated actual opioid consumption in the immediate two postoperative hours in patients randomized to paravertebral analgesia (with or without concomitant GA) vs GA alone. Our results are generally consistent with previous reports and show that patients given paravertebral analgesia had less immediate postoperative pain and required fewer morphine sulphate equivalents.…”

“…14 Paravertebral anesthesia was provided either with a thoracic (T) interspace 2-4 catheter or multilevel injections from T1 to T5. 15 When a catheter was used, it was inserted into the ipsilateral paravertebral space at the level of T2/3 or T3/4 using a standard technique. 2 Patients were given a bolus of 0.5% bupivacaine 10-20 mL or 0.5% ropivacaine with epinephrine after a test dose with 1.5% lidocaine and 1:200,000 epinephrine.…”