Erector Spinae Plane Block

1. Background
   1. Newly described trunk Regional Anesthesia as of 2016
   2. May be preferred over Serratus Anterior Nerve Block and Intercostal Nerve Block
2. Indications
   1. Chest wall Anesthesia
   2. Chest wall injury (e.g. Rib Fracture, transverse process Fracture)
   3. Incomplete coverage for Chest Tube placement
      1. Provides Anesthesia for the chest wall, but not the pleura
3. Anatomy
   1. Erector Spinae are a constellation of 3 muscle groups (each containing 3 muscles)
      1. Medial Muscles (Three spinalis muscles)
      2. Intermediate Muscles (Three longissimus muscles)
      3. Lateral Muscles (Three iliocostalis muscles)
   2. Erector Spinae muscles provide a tissue plane for Anesthesia to the hemithorax, chest wall
   3. Vertebral transverse process provides a convenient needle backstop for the tissue plane for injection
4. Preparation
   1. Identify and mark landmarks
      1. Midline Thoracic Back (spinous processes)
      2. Fourth Thoracic Vertebrae (T4) - just below Scapular spine which is at T3 level
   2. Skin preparation (e.g. Chlorhexidine)
   3. Drape region
   4. Sterile covering over Ultrasound high frequency linear probe (sterile gel inside and outside)
   5. Medication
      1. Confirm maximum dose for Ropivacaine (or Bupivacaine ) to prevent LAST Reaction
      2. Ropivacaine 0.2 to 0.375% (preferred over Bupivacaine 0.25%) 20-30 ml
      3. Syringe 30 ml
      4. Needle 22 gauge, 2-4" (5-10 cm)
5. Technique
   1. Images
      1. 
   2. Patient typically in seated position
   3. Ultrasound in vertical plane over midline Thoracic Spine
      1. High frequency linear probe
      2. Top of probe at T4 Vertebrae spinous process, in midline
      3. Ultrasound image should show several transverse processes to confirm vertical plane
      4. Injection site will be be ~2 cm lateral to midline overlying transverse process
         1. Midline spinous process (superficial rounded appearance)
         2. Lamina (deeper flat appearance)
         3. Transverse Process (superficial flat appearance) - Target Site
            1. Pleura should NOT be visualized
         4. Rib (deeper rounded appearance)
            1. Pleura and Sliding Lung Sign will be seen between ribs
   4. Injection Plane
      1. Inject from superior to inferior in line with transverse processes
         1. Down to level of transverse process (serves as backstop for needle)
      2. Target is space below the erector spinae muscle
6. References
   1. Krishnan and Cascella (2020) Erector Spinae Plane Block, Stat Pearls, accessed 12/21/2020
      1. https://www.ncbi.nlm.nih.gov/books/NBK557382/
   2. Martel (2020) Regional Anesthesia for Acute Care Conference, attended 12/11/2020
      1. https://stabroom.com/
   3. Erector Spinae Plane Block, NYSORA, accessed 12/21/2020
      1. https://nysoralms.com/courses/erector-spinae-plane-block/