How to Use Pectoral Nerve Blocks Effectively—An Evidence-Based Update.

Since the original description in 2011, the array of pectoral nerve blocks has evolved. The pectoral nerve (PECS) block in conjunction with general anesthesia can decrease an additional analgesic in perioperative period for breast cancer surgeries. Current literature on the PECS block has reported 3 several types (PECS I, PECS II, and serratus plane blocks). The PECS I block is the same as to the fi rst injection in the PECS II block. The second injection in the PECS II block and the serratus plane block blocks intercostal nerves (Th2–6) and provides an analgesic for the breast cancer surgery. However, the PECS I block (or fi rst injection in the PECS II block) has no analgesic, because both lateral and medial pectralis nerve blocks are motor nerves. PECS block in previous reports, when added to opioid-based general anesthesia, may improve analgesia and decrease narcotic use for breast cancer surgery. Moreover, PECS block compares favorably with other regional techniques for selected types of surgery. A major limitation of the PECS block is that it cannot block the internal mammary region. Therefore, some studies have reported its ability to block the anterior branches of the intercostal nerve. PECS block is an effective analgesic tool for the anterolateral chest. In particular, the PECS block can provide more effective analgesia for breast cancer surgery.