From the Guidelines
An interscalene nerve block is a highly effective regional anesthesia technique for providing pain relief in shoulder and upper arm procedures, particularly for rotator cuff repairs, and is recommended as the first-choice regional analgesic technique. It involves injecting local anesthetic between the middle and anterior scalene muscles in the neck, targeting the upper and middle trunks of the brachial plexus 1. The procedure is typically performed using ultrasound guidance or nerve stimulator technique to ensure accurate placement.
Key Points to Consider
- Commonly used medications for interscalene nerve block include ropivacaine or bupivacaine, which typically provide 12-24 hours of pain relief 1.
- A catheter can be placed for continuous infusion to extend the duration of pain relief.
- Patients should be aware of potential side effects, including temporary hoarseness, Horner's syndrome, and rarely, phrenic nerve blockade causing diaphragm weakness.
- The use of a regional analgesic technique, such as interscalene nerve block, is recommended as part of a multimodal analgesia approach, which also includes systemic analgesia with paracetamol and non-steroidal anti-inflammatory drugs (NSAID) 1.
- A single dose of intravenous dexamethasone is also recommended to increase the analgesic duration of interscalene brachial plexus block and decrease analgesic use 1.
From the Research
Definition and Purpose of Interscalene Nerve Block
- The interscalene nerve block is a method of regional anesthesia used to provide analgesia for surgeries involving the shoulder and upper arm 2, 3, 4.
- This block is particularly effective for procedures requiring anesthesia of the shoulder and proximal upper limb 3.
- The interscalene nerve block decreases pain, nausea, and vomiting associated with general anesthesia 2.
Techniques and Approaches
- The interscalene block is one of the four most common techniques used in the clinical setting for regional anesthesia of the upper limb, along with the supraclavicular block, the infraclavicular block, and the axillary block 3.
- The two most common methods for localizing the appropriate nerves for brachial plexus blocks, including the interscalene block, are nerve stimulation and ultrasound guidance 3.
- Ultrasound guidance has proven especially useful in patients with anatomical variations, allowing the operator to visualize the needle position within the musculature 3.
Efficacy and Outcomes
- Studies have shown that interscalene nerve blocks with perineural liposomal bupivacaine provide effective analgesia similar to perineural standard bupivacaine with dexamethasone 4.
- Ultrasound-guided interscalene nerve block using an ultralow volume of local anesthetic can be effective for the management of post-thoracotomy shoulder girdle pain, particularly in the shoulder area 5.
- The efficacy of the block can vary depending on the location of the pain, with better results observed in the shoulder area compared to the scapular area 5.