Chapter 150. Intercostal Nerve Blocks

• Thoracic surgery
• Rib fractures
• Open cholecystectomy
• Gastrectomy
• Mastectomy

(Figure 150-1)

• Nerve runs in a neurovascular bundle just inferiorly to the rib; the nerve is the most inferior structure in this bundle
• Nerve runs between the internal intercostal and the innermost intercostal muscles
• Lateral cutaneous branch begins at the midaxillary line; therefore, one should block proximally to this point
• The block should be done lateral to the beginning of the angle of the rib; the intercostal groove is largest here; therefore, theoretically safer

• Both sensory and motor at the level blocked; only ipsilateral side effected
• Skin, muscle, and parietal peritoneum, if being used for upper abdominal surgery postoperative analgesia, then additional coverage required for visceral pain
• Appropriate for thoracic and upper abdominal procedures
• Bupivacaine or lidocaine with epinephrine provides a block lasting an average of 12 hours

• Pneumothorax (<1%)
• Local anesthetic toxicity (this block has a high absorption of local anesthetic; consider the use of epinephrine in the local anesthesia to decrease systemic absorption)
• Hematoma
• Spinal or epidural anesthesia

• Put the patient in a sitting position (lateral and prone are also possible)
• Palpate and identify the appropriate level of intercostal spaces
• Identify the angle of the rib, usually about 7 cm from midline. The block can be performed anywhere proximal to the midaxillary line
• Lift the skin from the intercostal groove up over the rib
• Insert a 22G, 50-mm needle at a 20° cephalad angle; the needle should come in contact with the rib within about 1 cm (Figure 150-2)
• Walk the needle off of the rib inferiorly, but keep the 20° cephalad angle of the needle
• The nerve generally lies less than 3 mm deeper than the depth of the rib; a pop is often felt with a short bevel needle
• Inject 5 mL of local anesthesia at each level necessary; do not exceed the maximum dose for the chosen local anesthetic

(Figure 150-3)

• Ultrasound imaging can be used to identify the intercostal spaces. Especially helpful in obese patients or patients with challenging anatomy
• Similar to a landmark-based technique for positioning, a high-frequency linear probe can be placed vertically on the patients back to visualize the rib, intercostal space, and pleura
• The needle is inserted in an in-plane or out-of-plane technique paying close attention to the depth identified on the ultrasound image. ...