From the Guidelines
For a USG PEC 1 block, I recommend using a high-frequency linear ultrasound transducer to identify the pectoralis major and minor muscles, and the thoracoacromial artery between them, with the injection of 10-15 ml of 0.25% bupivacaine or 0.5% ropivacaine, as this provides adequate analgesia for 8-12 hours, as supported by recent studies 1.
Key Considerations for the Procedure
- The needle should be inserted in-plane from medial to lateral, with the injection point being between the pectoralis major and minor muscles.
- Ensure sterile technique with skin preparation using chlorhexidine and maintain visualization of the needle tip throughout the procedure to avoid intravascular injection or pneumothorax.
- This block primarily targets the medial and lateral pectoral nerves, providing analgesia to the anterior chest wall and is particularly useful for breast surgeries, pacemaker insertions, and post-mastectomy pain.
Medication and Duration
- The recommended medication is 10-15 ml of 0.25% bupivacaine or 0.5% ropivacaine, which provides adequate analgesia for 8-12 hours.
- For longer duration, adding dexamethasone 4 mg to the local anesthetic can extend the block to 18-24 hours, as suggested by studies 1.
Comparison with Other Blocks
- Paravertebral blockade is recommended as the first-choice regional analgesic technique, but pectoral nerves block may be used as an alternative, as noted in 1.
- Interfascial plane blocks such as PECS blocks could be performed in major breast surgery as an alternative to paravertebral blocks, with studies indicating their efficacy in reducing pain and opioid consumption 1.
Postoperative Pain Management
- Peri-operative pain management for breast surgery should include, unless contraindicated, paracetamol and a conventional NSAID or COX-2-selective inhibitor continued into the postoperative period, as recommended by 1.
- Opioids should be used only as a rescue medication if non-opioid analgesics and regional analgesic techniques do not provide effective pain control, emphasizing the importance of a multimodal approach to pain management 1.
From the Research
USG PEC 1 Block Method
The USG PEC 1 block method, also known as the Pectoral Nerve Block, is a regional anesthesia technique used to provide analgesia for patients undergoing breast surgery or other procedures involving the chest wall.
Recommended Technique
- The technique involves the use of ultrasound guidance to inject local anesthetic around the pectoral nerves, specifically the medial and lateral pectoral nerves 2.
- A single entry point-triple injection technique can be used, with the entry point just medial to the pectoral minor muscle, and three subsequent infiltrations: deep lateral part of the pectoralis minor muscle, between the pectoralis minor and major muscles, and between the pectoralis major muscle and its posterior fascia under ultrasound visualization 2.
Medication
- The recommended medication for the USG PEC 1 block method includes local anesthetics such as ropivacaine or bupivacaine, with or without epinephrine or magnesium sulfate 3, 4.
- The volume of local anesthetic used can vary, but studies have shown that 30 mL of 0.2% ropivacaine with 1:400,000 epinephrine or 28 mL of 0.25% bupivacaine with or without magnesium sulfate can be effective 3, 4.
Efficacy
- The USG PEC 1 block method has been shown to be effective in providing postoperative analgesia for patients undergoing breast surgery or other procedures involving the chest wall 3, 4, 5.
- The technique can reduce the need for opioid analgesics and improve patient outcomes, including reduced pain scores and improved sleep quality 4, 5.