Efficacy and safety of bilateral thoracic paravertebral blocks in outpatient breast surgery

Unilateral thoracic paravertebral blocks (TPVBs) have demonstrated reliable intraoperative analgesia, low postoperative pain scores, and an opioid-sparing effect in breast cancer surgery. However, secondary to the perceived risk of complications, bilateral TPVB have been less well accepted and are less frequently used. The purpose of this study was to evaluate the feasibility of using bilateral TPVBs in outpatient surgery for patients undergoing bilateral mastectomy with immediate implant-based reconstruction. Electronic medical records were retrospectively reviewed for patients receiving bilateral TPVBs for bilateral mastectomy with immediate implant-based reconstruction performed by a single surgeon from September 2012 to September 2015. Records were reviewed for incidence of complications, time to discharge, and incidence of unplanned admission or readmission. Clopper-Pearson method for binomial distribution was used to calculate confidence intervals for proportions. Forty-five patients undergoing bilateral mastectomy with immediate reconstruction received bilateral TPVBs. There were 4 TPVB-related complications, all of which were symptomatic hypotension or bradycardia (9%; 95% CI, 2%-21%). There was no incidence of symptomatic pneumothorax. Mean time to discharge readiness from the postanesthesia care unit (PACU) was 1.9 hours (SD = 1.0). Overall, 91% (n = 29) of the 32 patients scheduled for day surgery were discharged home as planned. Mean time from entry to PACU to home discharge for day surgery patients (n = 32) and planned admissions (n = 13) was 5.9 hours (SD = 4.3) and 16.3 hours (SD = 3.6), respectively. There was no incidence of readmission following discharge. Bilateral TPVBs can safely facilitate day surgery in carefully selected patients undergoing bilateral mastectomy with immediate implant-based reconstruction.