Epidural anaesthesia in cattle

Question 1

Types

Answer 1

Epidural Anesthesia

Caudal Epidural Anesthesia

Question 2

Epidural Anesthesia

Anatomic Considerations

Answer 2

• The spinal cord is covered by three membranes:
o Duramater
o Arachnoidmater
o Piamater
• The spinal cord ends at the lumbar region
• Lateral openings (intervertebral foramina) between the vertebral arches
• Spinal nerves are devided into two roots: dorsal (sensory) root and ventral (motoric) root

Question 3

Indications

Answer 3

• All surgeries posterior to the diaphragm

Question 4

Contraindications

Answer 4

• Damaged: lumbar or sacral vertebrae, spinal cord, congenital deformities
• Inflammation: near the injection site, within the vertebral canal
• Paresis or lameness of the hindquarters
• Very low blood pressure or circulatory collapse

Question 5

Administration

Answer 5

• Low caudal epidural: Insert the needle between the first (C1) and second coccygeal vertebrae (C2) (coccygo-coccygeal)
• High caudal epidural: Insert the needle between the last sacral (S5) and the first coccygeal vertebrae (C1) (preferred site) (sacro-coccygeal)
Desired effect
o Low caudal epidural anesthesia: S3, S4, and S5
o High caudal epidural anesthesia: S2, S3, S4, and S5

Question 6

Materials

Answer 6

• 10-ml plastic syringe
• 1.5-inch, 18-gauge, sterile needle
• 2 to 4 ml of 2.0% lidocaine
• Xylazine: 2 to 4 ml of 2.0% lidocaine + xylazine (20 to 30 mg)
• response delayed 15 to 20 minutes
• excellent anesthesia in a larger area
• mild sedation along with the anesthesia

Question 7

Epidural Anesthesia

Technique

Answer 7

• Remove hair from the injection site + antiseptic solution
• Standing restraint
• The surgeon should stand behind the animal
• Move the tail up and down to locate the fossa between the last sacral vertebra and the first
coccygeal vertebra (preferred site) or between the first and second coccygeal vertebrae

Question 8

Caudal Epidural Anesthesia

Technique

Answer 8

• Insert the needle (only) ventro-cranially at a 15-degree angle until the skin is penetrated
• Place a drop on the hub of the needle (hanging drop method)
• Anesthetic solution is drawn into the epidural space by negative pressure
• Attach a syringe to the needle and slowly inject
• Injection should go down freely (almost a gravity feeding)
• Optimal dose:
o Patient’s size and condition
o Obesity, which may influence the amount of spinal canal adipose tissue