Thoracic paravertebral blockade in breast surgery: Is pneumothorax an appreciable concern? A review of over 1000 cases

There has been a substantial increase in ambulatory day‐case breast surgery in recent decades. This has been largely due to improvements in anesthetic procedures and pre‐emptive analgesia. Thoracic paravertebral blockade (TPVB) is increasing in popularity, though concerns over iatrogenic injury remain, especially pneumothorax. The purpose of this study was to conduct a review of the incidence of pneumothorax following TPVB prior to breast surgery. Data from of a consecutive series of patients having TPVB prior to breast surgery between 2009 and 2014 were reviewed. TPVB were used prior to unilateral and bilateral procedures. Medical records were retrospectively assessed for any complication including pleural punctures, pneumothorax, hypotension, bradycardia as well as signs and symptoms of local anesthetic toxicity. 1152 patients underwent a total of 1322 TPVB injections (982 unilateral and 340 bilateral). Clinically significant hypotension and/or bradycardia occurred in 26 patients (2.2%). Two patients (0.17%) had a suspected toxicity from the local anesthetic. Incidence of pleural puncture was 0.6% (n=9) and pneumothorax 0.26% (n=3). All pneumothoraxes were managed conservatively. There was no statistical difference in complication rates in those that had unilateral vs bilateral TPVB or those that had ultrasound guidance (P=.09). Good pre‐emptive analgesia is pertinent to prevent acute postoperative pain. TPVB have been shown to be successful in reducing rescue analgesia. This study shows TPVB is a well‐tolerated procedure, with a low associated incidence of iatrogenic injury and complication.