Local, Regional and Spinal Anesthesia Flashcards
Why do we use local, regional or spinal anesthesia in food animal medicine?
Cheaper and less needed
-Get drug right where you need it faster
-Help mitigate pain
-Prevents us from having to lay them down for surgery/prevent complications
Why are ruminants’ poor candidates for general anesthesia?
Regurgitation, bloat, muscle damage
What are some drugs used for local anesthetics?
Lidocaine hydrochloride, mepivacaine, bupivacaine
What is the toxic dose of lidocaine in cattle? Small ruminants?
Cattle: 10mg/kg (300ml)
Small Ruminant: 5mg/kg (4.5ml)
How long is the duration of lidocaine?
1-2hrs
How can you increase the potency and duration of action of lidocaine?
Add epinephrine (NOT nreat the spine)
What is the mode of action of lidocaine?
Block fast voltage gated na channels in neuronal cell membrane - nerve conduction is inhibited
What type of blocks are used for a laparotomy? (DA, C-section, rumenotomy)
Line, inverted L, distal paravertebral, proximal paravertebral
How is a line block used?
Block area of paralumbar fossa, SQ into muscle and peritoneum, delayed healing possible complication
18G 1 inch
Describe the Inverted L block
Non-specific
behind 13th rib and ventral transverse processe of lumbar vertebrae
18g 1.5inch
Minimize incisional hematoma
150-200ml lidocaine
Stick many times
Describer the Distal Paravertebral Block
Desensitize T13, L1, L2 (Palpate L1, L2, L3 and L4)
18G 1.5inch
Lidocaine dorsal and ventral to transverse process 10-20ml per site
60-120ml lidocaine
Describe Proximal Paravertebral Block
T13, L1 and L2
18g 1.5inch
needle cranial edge L1, L2, L3
walk off cranial edge with 16g guide
6-10ml/site
What is the caudal epidural used for and what does it block?
Dystocia, prolapse, embryo transfer and flush
Block S5 down
Goal space for needle - S5-C1 - tail down when place needle
18G 1.5inch
Move tail to see sleepy
What is the technique called for caudal epidural?
hang and drop method (negative pressure in spinal cord sucks the drop in), then attach
What does the caudal epidural desensitize?
S2, S3, S4, S5
How much lidocaine goes in a caudal epidural?
Never more than 6-7ml (1ml/200lb)
Lidocaine dose for cattle epidural
1ml/200lb
What is the small ruminant epidural dose?
1ml/33lb
Why use a high volume caudal epidural?
Abdominal, udder, UT, c-section, down,
Dose: 4-6mg/kg (up to 8)
What does a lumbosacral epidural block?
For sedated animals - on ground - gets leg
- c-section SR
- use spinal needle
Wing of illeum land mark
What is the retrobulbar block used for?
Enucleation
-18G spinal needle, bend to get around globe
15-20ml lidocaine each site
What is the Peterson eye block?
Anesthetize skin and use 14G cannula, coronoid process
-15-20ml lidocaine
Although it is more challengig why is the peterson eye block better?
Less edema and inflammation
-desentize occulomortor, trochlear, abducent and trigeminal
-zygomatic arch landmark
What are the options for teat anesthesia and why do we use each?
Ring block - around base teat 5-10ml lidocaine
V-block
22-25G needle
Laceration or amputtion
