How does a proximal paravertebral block work?

• A. It anesthetizes the skin over the back
• B. It blocks the femoral nerve directly
• C. It blocks nerves from the intervertebral foramen
• D. It affects only superficial nerves

Answer: (C)

A proximal paravertebral block works by targeting the nerves that emerge from the intervertebral foramen, specifically the thoracic spinal nerves, which contribute to the innervation of the structures in the back and flank regions of large animals, particularly cattle. When administering this block, the local anesthetic is injected near the vertebral column, allowing it to diffuse around the spinal nerves as they exit the foramen, effectively interrupting the transmission of sensory impulses from the affected area.

This technique is particularly useful in procedures involving the abdominal and flank regions, as it provides a deeper level of anesthesia compared to blocks that only target superficial nerves or the skin, leading to more effective pain control during surgical interventions. The ability to anesthetize the nerves at the root level significantly decreases pain and discomfort associated with surgical techniques, making it an essential skill in the field of food animal anesthesia.