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

Area of Science:

• Anesthesiology
• Surgical Oncology
• Pain Management

Background:

• Pectoral nerve (PECS) blocks have evolved since their 2011 description.
• PECS blocks, combined with general anesthesia, can reduce perioperative analgesic needs for breast cancer surgeries.
• Literature describes three types: PECS I, PECS II, and serratus plane blocks.

Purpose of the Study:

• To review the evolution and efficacy of pectoral nerve blocks for breast cancer surgery.
• To compare the analgesic contributions of different PECS block variations.
• To highlight the role of PECS blocks in multimodal analgesia for breast cancer procedures.

Main Methods:

• Review of current literature on pectoral nerve blocks (PECS I, PECS II, serratus plane).
• Analysis of the anatomical targets and nerve pathways blocked by each PECS block variation.
• Comparison of PECS block efficacy with other regional anesthesia techniques.

Main Results:

• PECS I block (or the first injection of PECS II) targets motor nerves and lacks analgesic effect.
• PECS II block's second injection and serratus plane block target intercostal nerves (Th2–6), providing analgesia.
• PECS blocks are effective for anterolateral chest analgesia, particularly for breast cancer surgery, but may not cover the internal mammary region.

Conclusions:

• PECS blocks, especially PECS II and serratus plane blocks, offer significant analgesia for breast cancer surgery.
• These blocks can improve pain management and decrease opioid requirements when used with general anesthesia.
• PECS blocks represent a valuable tool for multimodal pain management in breast cancer patients, though limitations exist regarding internal mammary coverage.