Analgesic efficacy of the Pecs II block: a systematic review and meta-analysis.

Surgery is the primary therapeutic intervention for breast cancer and can result in significant postoperative pain. We searched the current literature and performed a meta-analysis in order to compare the analgesic efficacy of the pectoral type-2 (Pecs II) block with systemic analgesia alone and with a thoracic paravertebral block for breast cancer surgery. Primary outcome was postoperative opioid consumption in the first 24 h after surgery. Secondary outcomes were pain scores at 0, 3, 6, 9 and 24 h after surgery, intra-operative opioid consumption, time to first analgesic request and incidence of postoperative nausea and vomiting. We identified 13 randomised controlled trials that included 815 patients. The Pecs II block significantly reduced postoperative opioid consumption (standardised difference in means: -13.64 mg oral morphine equivalents; 95%CI: -21.22 to -6.05; p < 0.01) and acute postoperative pain at all intervals in the first 24 h after surgery compared with systemic analgesia alone. Compared with the thoracic paravertebral block, the Pecs II block resulted in similar postoperative opioid consumption (standardised difference in means: -8.73 mg oral morphine equivalents; 95%CI: -18.16 to 0.69; p = 0.07) and postoperative pain scores after first measurement. In conclusion, the Pecs II block offers improved analgesic efficacy compared with systemic analgesia alone and comparable analgesic efficacy to a thoracic paravertebral block for breast cancer surgery.