Purpose of nerve blocks?
Provide local pain management
Example: Dentistry and surgical cases (small & large animal)
What nerves are being blocked at the location of the low 4 point block?
Medial and lateral palmar nerves
What is bier blocking?
Technique for regional anesthesia used in horses to block pain in a limb, often for distal limb surgeries or diagnostics.
Procedure involves applying a tourniquet to the limb, exsanguinating it with a bandage, and injecting a local anesthetic into a vein distal to the tourniquet.
What is the main purpose of doing nerve blocks in horses?
Used as a diagnostic tool to evaluate for equine lameness!
Why are nerve blocks not done in other animals?
Less complicated in equines.
They have no muscles distal to the carpus = all sensory!
Why should we start nerve
blocks distally?
Nerves start to branch off distally as we go down the leg, we need to be able to differentiate which one is causing the problem.
If you start proximally, it’ll numb the whole leg.
How to do a palmar digital/heel nerve block?
Over neurovascular bundle above collateral cartilage BOTH sides.
What does a palmar digital/heel nerve block numb?
- Sole
- Navicular
- Distal interphalangeal joint
How to do an Abaxial sesamoid nerve block?
Abaxial border of BOTH sesamoids.
Have to do both medial and lateral aspects.
What does an Abaxial sesamoid nerve block numb?
Everything distal to fetlock:
- Sole
- Navicular
- Distal interphalangeal joint
- Dorsal hoof wall
How to do a Low palmar/Low 4 point nerve block?
- Distal end of both splint bones - Palmar metacarpal nerve
- Between suspensory and DDFT- Palmar nerve
- Careful of palmar pouches
What does a Low palmar/Low 4 point nerve block numb?
EVERYTHING at the fetlock and below.
Includes:
- The fetlock joint itself
- All structures of the pastern
- All structures of the hoof
- All flexor tendons (SDFT, DDFT)
- Suspensory ligament + extensor branches
- Navicular region
- All skin distal to the fetlock
How to do a High palmar/high 4
block?
Similar to low 4 but above
communicating branch!
Red?
Ulnar nerve
Orange?
Median nerve
Yellow?
Lateral palmar metacarpal nerve
Green?
Medial palmar metacarpal nerve
Light blue?
Lateral palmar nerve
Dark blue?
Medial palmar nerve
Pink?
Medial dorsal digital nerve
As medial palmar nerve passes the fetlock, it branches dorsally and turns into the medial dorsal digital nerve.
Purple?
Lateral dorsal digital nerve
Brown?
Lateral palmar digital nerve
Grey?
Medial palmar digital nerve?
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Directional Terminology35
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Electrolyte Movement38
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Membrane Potential15
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Action Potential24
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Bone Biology & Development121
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Bone Histology85
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Carpal, Metacarpal, & Distal Joints (Review)7
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Connective Tissue & Cartilage79
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Ultrasound Basics56
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Joint Physiology68
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Radiographic Positioning & Projections43
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Nerves5
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Hoof Structures & Function88
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Nerve Blocks23
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Muscle Anatomy & Function53
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Stifle & Stay Apparatus58
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Cruciate Injuries & Ortho Palpation46
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Muscle Histology64
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Neuromuscular Junctions48
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Action Potential to Calcium Release62
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Gait & Lameness88
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Muscle Contraction & Relaxation88
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Formative Review Questions43
