Analgesics PT 1

Question 1

Pain

Answer 1

Unpleasant sensory and emotional experience associated with actual or potential tissue

Question 2

Nociception

Answer 2

Detection of noxious stimulus at the tissue level by nociceptors

Question 3

Nociceptors

Answer 3

Free nerve endings of primary afferent neurons

Question 4

Nociception pathway

Answer 4

Transduction- peripheral stimuli into action potential
Transmission- peripheral nerves to spinal cord and brain
Modulation- dorsal horn of spinal cord
Projection- 2nd order neurons project input to thalamus
Perception - integration of signal in the brain

Question 5

Receptors located on the distal terminus of primary sensory nerve fibers

Answer 5

• AB fibers
• A delta fibers
• C fibers

Question 6

Chronic pain

Answer 6

Pain persist longer than is providing protection

Question 7

Neuron alteration occurs through two main changes

Answer 7

• peripheral sensitization-Nociceptor

- central sensitization- modulation

Question 8

Hyperalgesia

Answer 8

Exaggerated perception of pain produced by a noxious stimulus

• -primary -occurs in tissue damage
• -secondary- beyond region of injury

Question 9

Allodynia

Answer 9

Non noxious stimulus elicits pain

Question 10

Main effect of Local anesthetic

Answer 10

Reversible blockade of transmission in peripheral nerves or spinal cord to stop pain signal from processing

Question 11

Amides are metabolized where.

Answer 11

Liver

Question 12

Esters are hydrolyzed by?

Answer 12

Plasma esterases

Question 13

Amide have what type of half life?

Answer 13

Long T1/2 (2-6hrs)

Question 14

Ester have what type of half life

Answer 14

Short half life (mins)

Question 15

Metabolites are excreted in…

Answer 15

Urine

Question 16

Route of administration of local anesthetic

Answer 16

• topical (skin/wound site)
• local infiltration (peripheral nerve block)
• intravenous regional anesthesia (biers block)

Question 17

Regional anesthesia

Answer 17

• minor procedures (skin biopsy)
• lameness localization (nerve block on equine)
• Epidural

Question 18

Pre and post operative analgesia

Answer 18

Nerve blocks and line blocks (closure in SX)

Question 19

Wound management

Answer 19

Intercostal nerve blocks (in between ribs)

Question 20

Peri-operative analgesia

Answer 20

Left displaced abomasum (LDA) surgery in ruminants

Question 21

Local anesthetic

Answer 21

• completely block nociception at site of injury or surgery
• reversible blockade of transmission in peripheral nerves or spinal cord to stop pain signal from progressing
• administered directly at the site of action (topical or inject)

Question 22

Brachial plexus block

Answer 22

• anesthesia for structures distal to elbow

- with nerve stimulation, effective from mid humerus distally

Question 23

Intercostal nerve block

Answer 23

• use bupivicane
• • injections three ribs anterior and two ribs posterior
• – thoracotomy , chest tube, rib fracture

Question 24

Benefits of regional analgesia

Answer 24

• less sedation
• decrease nausea and vomiting
• decease CV and pulmonary complications
• decrease morbidity and mortality

Question 25

Risk of regional analgesia

Answer 25

- local anesthetic toxicity (use lowest effective dose) | - nerve injury (trauma, toxicity, ischemia

Question 26

Glutamate and NMDA receptors increase in excitatory neurotransmitters (NT) causing

Answer 26

Dorsal horn neural hyperexcitability

Question 27

NMDA receptor

Answer 27

Play central role in chronic pain | -- dorsal horn wind up --> 2nd order neurons respond more intensely to repeated stimulation

Question 28

Glutamate

Answer 28

Powerful excitatory NT--> excite neurons | - increased of glutamate is able to activate normally closed NMDA receptors

Question 29

Neurologic blockade

Answer 29

- Prevent depolarization - Block propagation of an action potential - -- inhibiting the influx of sodium through voltage dependent NA+ channels

Question 30

All locally anesthetic are sodium channel blockers ..T or F

Answer 30

True

Question 31

Which ester is an-local anesthetic

Answer 31

Proparacaine

Question 32

Which of the following nociception processes is least affected by administration of local anesthetic drugs?

Answer 32

Perception..is not a target