Meißner M, Austenfeld E, Kranke P, et al. - Via performing a systematic review of randomised controlled trials (RCT) with meta-analysis and risk of bias assessment, researchers sought to determine postoperative pain outcomes and adverse events of a Pectoral nerve blocks (PECS block) vs no treatment, sham treatment or other regional anaesthetic techniques in women undergoing breast surgery. From the databases MEDLINE, CENTRAL (until December 2019) and clinicaltrials.gov, they identified a total of 24 RCTs (1,565 patients) for inclusion. Moderate quality evidence was gained suggesting that postoperative pain intensity at rest reduces in correlation with receiving PECS block vs no treatment. Less pronounced results were observed if patients were administered a sham block. Additionally, there might be equal effectiveness of PECS blocks vs PVBs.