Bovine Flash Notes - Flank Anesthesia

Question 1

local anesthesia done on the flank of cows is concerned with what spinal nerves?

Answer 1

T13, L1, & L2

Question 2

what is a line block?

Answer 2

infiltration of the intended incision line

Question 3

what is the most common nerve block done on ruminants for flank anesthesia?

Answer 3

line block

Question 4

what is an inverted L block?

Answer 4

injections are done in the abdominal wall from the subcutaneous area to the peritoneum in an ‘L’ or backwards 7 pattern

Question 5

what is the purpose of using any type of paravertebral block?

Answer 5

to be able to perform standing flank surgery by opening the paralumbar fossa

Question 6

what is a magda/distal paralumbar analgesia block?

Answer 6

blocks only the ventral & lateral dorsal branches of spinal nerves

Question 7

what are the advantages & disadvantages of using a line block for flank anesthesia?

Answer 7

advantages - easy to do, disadvantages - edema in the incision site & possible interference with healing

Question 8

how is an inverted L block done?

Answer 8

line infiltration Is done cranial & dorsal to the intended incision site - two lines are laid down, one caudal to the last rib & one ventral to the transverse processes of the lumbar vertebrae - up to 100mL are injected, wait 10-15 minutes

Question 9

what are the advantages & disadvantages of an inverted L block?

Answer 9

advantages - easy to do & away from incision site, disadvantages - large amount of anesthetic required

Question 10

what nerves are desensitized when using a proximal paravertebral block?

Answer 10

dorsal & ventral nerve branches of T13, L1, & L2 as they emerge from the intervertebral foramina

Question 11

where is a proximal paravertebral block performed?

Answer 11

injection sites are 1-2 inches lateral to the dorsal midline over the cranial edge of the transverse processes of L1 & L2 - for T13, pass the needle ventrally to contact the transverse process of L1 & walk needle off the cranial edge of the transverse process & through the intertranverse fascia below the transverse process for the ventral branch, withdraw the needle back a bit to get the dorsal branch, & repeat the process for L1 & L2

Question 12

what nerves are desensitized with a distal paravertebral block?

Answer 12

T13, L1, & L2 - dorsal & ventral branches

Question 13

where is a distal paravertebral nerve block performed?

Answer 13

done at the distal end of the transverse processes of L1, L2, & L4

Question 14

what are the advantages of using a distal paravertebral nerve block over a proximal one?

Answer 14

advantages - no scoliosis because not all branches of the dorsal branches are blocked, minimum pelvic limb paresis, no danger of hitting abdominal vessels, & uses standard needles sizes

Question 15

what are the disadvantages of using a distal paravertebral nerve block?

Answer 15

disadvantages - more anesthetic needed, effectiveness can vary especially if the nerves vary

Question 16

where is a lumbosacral epidural performed on a cow? what is it?

Answer 16

anesthetic is administered into the epidural space between the first & second lumbar vertebrae - locate spinous processes of L1 & L2 by palpating the transverse processes of L1 & L2 - desensitization of the nerve roots as they leave the spinal cord

Question 17

what are the advantages of using a lumbosacral epidural over a proximal or distal paravertebral nerve block?

Answer 17

advantages - only one injection, small amount of anesthetic, & uniform analgesia

Question 18

what are the disadvantages of using a lumbosacral epidural over a proximal or distal paravertebral nerve block?

Answer 18

disadvantages - difficult technique, motor loss to hind limbs, & possibility of damage to the spinal cord & venous sinuses