Thoracic paravertebral regional anesthesia improves analgesia after breast cancer surgery: a randomized controlled multicentre clinical trial.
BACKGROUND
The contribution of regional anesthesia with thoracic paravertebral blockade to postoperative analgesia remains unclear. We compared the effect of a combination of paravertebral blockade and propofol general anesthesia (GA) with sevoflurane GA and opioid analgesia on postoperative pain and opioid use for patients undergoing breast cancer surgery.


METHODS
Patients having breast cancer surgery were randomly assigned to paravertebral analgesia with propofol GA (PPA, n = 187) or sevoflurane GA with perioperative opioid analgesia (SOA, n = 199). The PPA and SOA groups were compared for opioid consumption and pain outcomes (on a 0-10 visual analogue scale [VAS]) at two hours postoperatively using superiority and inferiority statistics. We compared our results with previous publications in a meta-analysis.


RESULTS
Compared with the SOA group, the PPA group experienced reduced median [interquartile range] pain VAS scores (1 [1,3] vs 2.5 [1,4], respectively; median difference -1.0; 99% confidence intervals [CI]: -1.5 to -0.5) and required less intraoperative fentanyl (50 [0, 125] µg vs 200 [100, 300] µg, respectively; median difference -100; 99% CI: -150 to -100) and less long-acting opioid (0 [0, 0] mg vs 3.0 [0, 12] mg, respectively, morphine equivalents; median difference -3; 99% CI: -4 to -2). Thus, non-inferiority was detected for all the above outcomes, and superiority tests for each outcome were highly significant in the expected directions (P < 0.001). Meta-analysis, including the current study, estimated a reduction in worst pain of 2.3 points (95% CI: 1.8 to 2.8) on a 0-10 scale and a 72% reduction (95% CI: 42 to 87) in mean opioid consumption in the immediate two postoperative hours for PPA vs SOA.


CONCLUSION
Our results were largely consistent with previous much smaller studies. Compared with sevoflurane GA with opioid analgesia, the combination of paravertebral analgesia with propofol GA provides an early clinical analgesic benefit in females having breast cancer surgery. This analysis is a substudy of an ongoing multicentre double-blinded randomized trial ( www.clinicaltrials.gov , NCT00418457) of cancer recurrence.