Thoracic paravertebral B-lock for breast cancer surgery: A randomized double-blind study

BACKGROUND: We examined in this randomized, double-blind study whether a multilevel paravertebral block performed before general anesthesia with propofol and a laryngeal mask enhances postoperative analgesia after breast cancer surgery. METHODS: Eighty-eight patients were randomized to receive paravertebral injections with either ropivacaine 0.5% (30 mL) or an equivalent amount of isotonic saline. Nine patients were excluded after randomization, thus 79 patients remained for evaluation (ropivacaine, n = 38; placebo, n = 41). Variables of efficacy were the amount of fentanyl delivered by the patient-controlled analgesia device in the postanesthesia care unit (PACU), postoperative pain measured on a numeric rating scale at regular intervals from the day of surgery and until the second postoperative day. RESULTS: The median consumption of fentanyl in the PACU was less in the ropivacame group compared with the placebo group (0 mu g [range: 0-250 mu g] versus 100 mu g [range: 0-800 mu g], P = 0.001). Also, fewer patients in the ropivacaine group reported pain >= 3 on the numbers rating scale in the PACU (13 vs 31, P < 0.0001). No statistical difference in pain scores or consumption of analgesics could be demonstrated after discharge from the PACU. CONCLUSIONS: A multilevel paravertebral block provides good analgesia for breast surgery, but the duration of analgesia is briefer than described in previous studies.