The peripheral nerves which innervate the chest and abdominal wall originate from the thoracic and lumbar plexuses. Regional anesthesia of the trunk focuses on the blockage of pain impulses from these areas to their corresponding location within the spinal cord.
This block provides analgesia to the thoracic and upper abdominal areas and has been shown to be efficacious in a variety of surgeries such as thoracotomy, breast surgery, and video-assisted thoracoscopy. Intercostal nerve blocks may be indicated for rib fractures, herpes zoster, cancer pain, and thoracotomy pain. Anticoagulation is a strong contraindication to this block due to the nerve’s proximity to the intercostal artery and vein. Potential adverse side effects include intravascular injection and pneumothorax due to the close proximity to the lung.
The technique focuses on the intercostal nerves which arise from the ventral rami of thoracic nerves T1 to T11 (Figure 15-1). The patient position can be prone, seated, supine, or lateral in order to perform the block. The dermatome and rib level is identified and the rib is palpated to the posterior axillary line, which is then marked and prepped in a sterile fashion. A 22 or 25 gauge needle is attached to a syringe and advanced perpendicular to the skin, aiming for the middle of the rib. Bony contact should be made and the needle should be walked down the rib inferiorly until bone contact is lost. This is where the intercostal groove containing the intercostal nerve, artery, and vein is located. The needle should be advanced approximately 2 mm while carefully aspirating to ensure that the needle is not within the lumen of the intercostal vein or artery. Injection of 3–5 mL of local anesthetic is sufficient. This block may be repeated at multiple levels to cover the anticipated pain area.
Intercostal nerve block. (Reproduced with permission from Butterworth JF, Mackey DC, Wasnick JD, eds. Morgan & Mikhail’s Clinical Anesthesiology, 5th ed. McGraw-Hill Education, Inc., 2013, Fig. 46-61.)
Paravertebral Nerve Block
This block provides analgesia to the thoracic and upper abdominal areas and is effective for breast surgery, thoracic surgery, and the management of rib fractures. It is used for both acute and chronic pain management and provides ipsilateral motor, sensory, and sympathetic blockade. Several advantages of paravertebral block over epidural anesthesia include a lower incidence of hypotension, urinary retention, respiratory problems, and postoperative nausea and vomiting. The paravertebral space is targeted adjacent to the vertebral bodies where the spinal roots exit the spinal canal. The paravertebral space is bounded by the costotransverse ligament with the parietal pleura anteriorly and transverse process and ribs posteriorly. Laterally, the space is continuous with the intercostal space. The vertebral body, intervertebral disc, and intervertebral foramen (which communicates with the ...