Interscalene Block
- Continuous interscalene block (CISB) is indicated for shoulder analgesia and can be achieved by local anesthetic infusion through a catheter placed in the interscalene groove (see Catheter Technique)
- The out of plane needle approach is generally recommended for CISB with the needle inserted high up in the neck (C4-5 level). Distal needle insertion and catheter advancement may result in distal anesthesia in the hand without adequate shoulder analgesia.
- Injection of local anesthetic or D5W solution (if nerve stimulation is desired) through the needle to distend the interscalene groove is recommended to facilitate the ease of catheter advancement.
- Local anesthetic spread can be observed in real time during catheter injection.
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A. A nerve root (arrowheads) in the proximal interscalene groove |
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B. Fluid injection through the block needle (arrow) to distend the interscalene groove prior to catheter insertion |
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C. Local anesthetic (LA) spread in the proximal interscalene groove after catheter injection; the hyperechoic dot = catheter |
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D. Local anesthetic (LA) spread in the distal interscalene groove after catheter injection; the hyperechoic dots = transverse view of a coiled catheter |
1. A Parasagittal Scan To Visualize Nerve Roots Emerging From The Neural Foramina
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A longitudinal scan with the transducer positioned parallel to the trachea on the left side of the neck
This can be a useful technique to locate higher cervical nerve roots (above C5). |
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A transverse view of the brachial plexus in the parasagittal plane
Arrowheads = nerve roots
NF = neural foramen
SCM = sternocleidomastoid muscle |
2. Vertebral Artery in The Lower Interscalene Groove Below C6
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ASM = anterior scalene muscle muscle
SCM = sternocleidomastoid |
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The vertebral artery (VA) is visualized usually when the transducer is scanning below C6 because the artery is housed within the foramina of the C1-C6 transverse processes. |
3. Aberrant Nerve Root
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A. A nerve root (between 2 arrowheads) is visualized between the sternocleidomastoid muscle (SCM) and the anterior scalene muscle (ASM) in the proximal interscalene region. |
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B. The same nerve root has now moved towards the interscalene groove (dashed line) as the transducer is moved caudally.
ASM = anterior scalene muscle
SCM = sternocleidomastoid muscle
Pictures: courtesy of Dr. Andre Ceccoli, France. |
Interscalene Block (In Plane Approach)
Interscalene Block, Lateral Decubitus Position (In Plane Approach)
Interscalene Block (In Plane Approach) - January 2009 NEW
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