What are the primary landmarks for performing a distal paravertebral block?

• A. L1, L2, L4
• B. L1, L3, L5
• C. T12, L1, L3
• D. T13, L2, L4

Answer: (A)

The primary landmarks for performing a distal paravertebral block include L1, L2, and L4 because these vertebrae correspond to the locations where the nerves responsible for sensation and motor function of the abdominal wall are most effectively blocked.

In cattle, a successful distal paravertebral block typically involves targeting the area around the nerves emerging from the spinal cord at these lumbar levels. Specifically, L1 and L2 provide sensory innervation to the skin and muscles of the abdominal wall, while L4 plays a complementary role in ensuring comprehensive anesthesia over the desired area. Proper identification and targeting of these landmarks are crucial for effective anesthesia during surgical procedures on the abdomen or flanks of the animal.

Other options listing vertebrae such as L3 or T12 would not be as suitable for achieving the desired anesthetic effect in the context of a distal paravertebral block, as they do not align with the primary nerves involved in abdominal innervation as effectively as L1, L2, and L4 do.