The Pectoral (PECS) Regional Block: A Scoping Review

Among the various surgical procedures, breast surgeries rank as a frequently conducted procedure. Interfacial blocks such as the Pectoral (PECS) block became possible with the currently available knowledge on innervations and ultrasound. Interfacial blocks target the deep fascial planes, which are potential spaces for injecting local anesthetics. The Pectoral I (PECS I) consists of the injection of local anesthetics in the plane between the pectoralis major and minor muscles. The PECS II block, a modified version of the block, is achieved by adding another, deeper injection in the plane between the pectoralis minor and the serratus anterior muscle. We conducted a scoping review using Arkesy and O’Malley's framework, as described by Levac. We identified our research question as the uses of the PECS regional block technique with the choice of local anesthetics, including adjuncts, and its effectiveness in intraoperative and postoperative analgesia in the first 24 hours and incidence of postoperative nausea and vomiting. Subsequently, we identified the relevant studies that met our inclusion criteria and charted the data. Lastly, we summarized and reported the results. The PECS block was used in various breast surgeries, among which radical mastectomies with/without lymph node dissection were the most common. It was found that the PECS block reduced intraoperative opioid consumption in 60% and 24-hour postoperative opioid consumption in 93.3% of the included papers. Various local anesthetics were used such as ropivacaine, bupivacaine, and levobupivacaine. Ultrasound-guided interfacial plane blocks, such as the PECS block, are a recent development in regional anesthesia that offers analgesia for patients undergoing breast surgeries. The authors conclude that PECS block can provide a decrease in intraoperative and postoperative opioid consumption, a decrease in the incidence of nausea and vomiting, and can lead to overall patient satisfaction in terms of lower pain scores compared to systemic analgesia.