23. Proximal lumbar paravertebral nerve block in cattle

Question 1

Proximal lumbar paravertebral nerve block in cattle Indication?

Answer 1

Proximal lumbar paravertebral nerve block in cattle.

A part of local and regional anaesthesia for the abdominal wall together with the distal lumbar paravertebral and the

inverted L paralumbar plane (nerve blocks)

Indication

• In standing animal: right or left sided flank laparotomy

Question 2

Pre-infusion procedure?

Answer 2

Pre-infusion procedures

• Prepare the injection site
• Preanesthetic sedation or analgesia as needed (IV route suggested)
• Excessive sedation may cause the animal to lie down

Question 3

Materials used?

Answer 3

Materials

• 4- to 5-inch (10-12 cm), 16- to 18-gauge spinal needle
• 1-inch (2,5 cm), 14-gauge guide needle to act as a cannula through the skin

(preferred) or a bayonet-tip blade to make a small stab incision in the skin to

facilitate needle insertion.

• 20-ml plastic syringe
• 2% lidocaine (with or without epinephrine)

Question 4

Basic technique?

Answer 4

Basic Technique

1. Locate the transverse process of L1: count backward from L5 ( the last palpable transverse process)
2. Block the nerve:

o NT13 along the cranial edge of transverse process L1

o NL1 along the caudal edge of transverse process L1

o NL2 along the caudal edge of transverse process L2

3. Guide needle and inject:

o 4 to 5 cm (2 to 2.5 inches) lateral to the dorsal midline

o Inject 5 ml of 2% lidocaine to anesthetize the skin

o Needle should be nearly vertical, move it up and down and inject slowly:

o 10-15 ml 2% lidocaine ca.1 cm (0,5 inch) above and 1cm below the edge of the transverse process

o 10-15 min for proper anaesthesia

o Anesthetizes both dorsal and ventral branches

Question 5

Common causes of failure?

Answer 5

Common causes of failure

• Difficulty in identification of lateral process of L1
• Needle at an angle rather than straight up and down
• Too quick injection (not spreading out the aesthetic solution)

Question 6

Results of successful technique?

Answer 6

Results of successful technique

• The blocked area initially becomes warm
• Skin, muscle, and peritoneum will be effectively anesthetized
• Scoliosis → unilateral desensitization of the longissimus dorsi muscle (movability altered; not in distal)