Nerve block efficacy in breast augmentation: A systematic review and meta-analysis.

Breast augmentation is often performed as a day-case general anaesthetic operation, with postoperative, opioid-based analgesia regimens. However, it may also be performed using regional anaesthesia; a variety of nerve block techniques are available to reduce postoperative pain and analgesic requirements. This systematic review and meta-analysis were undertaken according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis guidelines comparing breast augmentation using regional anaesthesia with general anaesthesia, versus general anaesthesia alone or with local field infiltration. All randomised or quasi-randomised studies that recruited adult female patients undergoing breast augmentation using regional anaesthesia were considered. The primary outcome measures were postoperative pain and analgesic requirements. A randomised effects model was used, with standardised mean difference or mean difference outcomes used as appropriate. Thirteen studies were included for systematic review, out of which eight met the inclusion criteria for meta-analysis. Nerve blocks had statistically significant standardised mean difference reductions in postoperative pain scores across all time points: 0 h (-1.2 [-2.1 to -0.3], p = 0.01, I = 85%), 1 h (-1.3 [-2.1 to -0.5], p = 0.002, I = 89%), 2 h (-1.8 [-2.8 to -0.9], p = 0.0002, I = 88%), 4-6 h (-1.2 [-2.1 to -0.4], p = 0.006, I = 89%), 24 h (-1.4 [-2.5 to -0.2], p = 0.02, I = 94%). There was also a statistically significant reduction in postoperative opioid requirements: -150 mcg fentanyl (-259.2 to -40.9), p = 0.007. Although an element of study heterogeneity is noted, this systematic review and meta-analysis support the concept that regional anaesthesia using nerve blocks in breast augmentation surgery, reduces both postoperative pain and opioid requirements, compared with general anaesthesia.