L3b: pain blocks and pain evaluation

what point of the pain pathway do opioids take effect?

1. perception

2. modulation

what point of the pain pathway do NSAIDS take effect?

transduction

what point of the pain pathway do alpha-2 agonists for analgesia take effect?

1. perception

2. modulation

what point of the pain pathway do local anesthetics take effect?

1. transmission

2. transduction

what point of the pain pathway do NMDA receptor antagonists take effect?

modulation

what point of the pain pathway do gabapentinoids take effect?

modulation

intraperitoneal instillation (splash block)

instillation of local anesthetic on an open wound or surgical site before skin closure

infiltration anesthesia

injection of local anesthetic agent adjacent to the area being blocked

what are examples of line blocks?

1. inverted L block

2. prescrotal block

3. wound infusion catheters

4. ring block

what is the technique for an intratesticular block?

1. hold the testicle

2. place the needle through caudal pole

3. tip of needle in the center of testicle

4. aspirate and inject until turgid

peripheral nerve blocks

injection of local anesthetic around a peripheral nerve

what are the techniques for peripheral nerve blocks?

1. blind (use anatomical landmarks)

2. nerve stimulator

3. ultrasound guid

what number do you want the nerve stimulator reading to be below?

0.20 to make sure you are not in the nerve

facial plane blocks

local anesthetic injected into space between fascias and spreads along the plane

what are the different types of facial plane blocks?

1. erector spinae plane block

2. serratus block

3. subscalene brachial plexus block

4. quadratus lumborum block

5. GIN + QLB caudal

what area is blocked with a ESPB?

epaxial area

what area is blocked with a serratus block?

thoracic wall

what area is blocked with a subscalene brachial plexus block?

forelimb

what area is blocked with a TAP block?

abdominal wall

what area is blocked with a QLB?

abdomen wall and content

what area is blocked with a GIN + QLB caudal?

pelvic limb

epidural block

administration of local anesthetic in the epidural space

spinal block

administration of local anesthetic in the subarachnoid space

neuraxial anesthesia

block trasmission in the spinal nerves within the canal to prevent pain signals from reaching CNS

what drugs are commonly used for epidurals?

1. local anesthetic and opioids

2. adjuvants (dexmedetomidine, medetomidine, ketamine)

what are the approaches of an epidural?

1. lumbosacral

2. sacrococcygeal

3. intercoccygeal

4. thoracolumbar

what are the advantages of an epidural?

1. excellent intra and post op analgesia

2. reduce requirement for general anesthetisa and systemic opioids

3. attenuates surgical stress response

what are the potential complications of an epidural?

1. hypotension

2. urinary retenion

3. infection or epidural hematoma

4. accidental intrathecal or intravascular injection

what are the indications for an epidural?

1. perineal and anal procedures

2. pelvic limb surgeries

3. C section

4. urogenital surgeries

5. perioperative pain management

what is evaluated for the feline grimace scale?

1. ear position

2. orbital tightening

3. muzzle tension

4. whiskers change

5. head position

what is the cut-off value for the feline grimace scale?

any pain more than a 4 needs to be addressed

what is the maximum score for the feline grimace scale?

10

what score for the glasgow pain scale inidicates rescue analgesia?

1. equal to or greater than 6/24

2. equal to or grater than 4/20

what is the glasgow pain scale only validated for?

acute pain in dogs

how is pain assessed on conscious animals?

pain scales

how is pain assessed on unconscious animals?

1. sympathetic stimulation

2. increase in HR, BP, and or RR of more than 25% for more than 2 minutes

noiception

perception of pain

what do we do if during a surgical procedure we believe the animal to have noiception?

give an analgesia asap!