Analgesia

Question 1

Define: Analgesia

Answer 1

Absence of awareness of pain

Question 2

Define: Pain

Answer 2

An unpleasant sensory & emotional experience associated with actual or potential tissue damage
*Untreated pain leads to patient suffering & prolongs recovery from surgery

Question 3

Define: Nociception

Answer 3

The nerve cells involved in the detection of actual or potential tissue injury (pain) by the central nervous system

Question 4

What are the 4 stages of pain perception?

Answer 4

1. Transduction
2. Transmission
3. Modulation
4. Perception

Question 5

Transduction refers to?

Answer 5

• Tissue injury from physical trauma including burns/chemical burns
• Transformation of noxious thermal, chemical, or mechanical stimuli into action potentials by peripheral A-Delta & C fibers
  *Essentially once you get hurt pain receptors are notified & nerve fibers send the pain response to the spinal cord/brain

Question 6

A Delta Nerve Fibers are found & are generally used in response to what type of pain?

Answer 6

• Found Joints & Skin
• Sharp Distinct Pain

Question 7

C Nerve Fibers are found where & are used in response to what type of pain?

Answer 7

• Found: Internal Organs especially the abdominal cavity
• Dull achy throbbing pain

Question 8

Transmission refers to what?

Answer 8

Conduction of sensory electrical impulse to the spinal cord.
*When the pain response moves through to the spinal cord

Question 9

Modulation

Answer 9

Neurons in the spinal cord amplify or suppress the sensory impulse received from the peripheral nociceptors

Question 10

Perception

Answer 10

Sensory impulse is transmitted to the brain where it is processed & recognized as pain

Question 11

Multimodal Analgesia

Answer 11

Using a combination of analgesic drugs, each with a different mechanism of action to control different pain

Question 12

Pain may be classified as?

Answer 12

1. Adaptive Pain
2. Maladaptive Pain

Question 13

Adaptive Pain

Answer 13

Is the normal sensory response caused by tissue damage/injury & inflammation
*Acute & Chronic

Question 14

Maladaptive Pain

Answer 14

• Results from physical changes that occur in the normal spinal cord & brain if adaptive pain is not managed appropriately

Question 15

Increased nociceptor sensitivity can lead to?

Answer 15

Increase nociceptor stimuli caused by non-noxious stimuli

Question 16

Define:

Answer 16

HyperalgesiaIncreased sensitive to noxious stimuli

Question 17

Allodynia

Answer 17

Pain produced by non-noxious stimuli

Question 18

Windup

Answer 18

CNS hypersensitive to noxious & non-noxious stimuli

Question 19

Somatic Pain

Answer 19

Arising from skin, sc tissue, muscles, bones & joints

Question 20

Visceral Pain

Answer 20

C fibers transmit this pain
Arising from internal organs

Question 21

Neuropathic Pain

Answer 21

Pain arising from direct damage to peripheral nerves or the spinal cord

Question 22

Acute Pain

Answer 22

Typically adaptive pain
Sudden onset w/ short duration

Question 23

Chronic Pain

Answer 23

Slow onset w/ longer lasting effect

Question 24

Preemptive Analgesia

Answer 24

◦ Administration of an analgesic before tissue damage occurs or the patient has awareness of pain
◦ Reduces the analgesic requirements as well as how long the patient will need analgesics for pain control
◦ Opioids
◦ Alpha 2 Agonists
◦ Local Anesthestics
◦ Nonsteroidal Anti-Inflammatory Drugs (NSAIDS)

Question 25

Postoperative Analgesia:

Answer 25

◦ Administration of analgesic agents for a few hours to a few days following surgery ◦ Repeated doses of oral or parenteral analgesic agents may need to be administered over an extended period of time ◦ Opioids ◦ NSAIDs ◦ Local Anesthestics ◦ Ketamine ◦ Alpha-2 Agonists

Question 26

What common anagelsia drugs are administered by CRI?

Answer 26

1. Diazepam 2. Dobutamine 3. Dopamine

Question 27

Why are CRI’s becoming more popular?

Answer 27

◦ Provides stable plane of analgesia ◦ No peaks or troughs ◦ Lower drug dosage delivered ay any point in time ◦ Greater control over drug administration

Question 28

What analgesics drugs can be used for CRI’s?

Answer 28

1. Opioids - Morphine & Fentanyl 2. Lidocaine *Pain relief abdominal surgery 3. Ketamine *Maladaptive pain 4. Alpha-2 Agonist *Dexmedetomidine - helps w/ restlessness after surgery

Question 29

What are common opioids used for moderate to severe pain control?

Answer 29

1. Morphine 2. Oxymorphone 3. Hydromorphone 4. Fentanyl

Question 30

What are common opioids used for mild to moderate pain control?

Answer 30

1. Buprenorphine 2. Butorphanol 3. Meperidine 4. Nalbuphine

Question 31

Morphine works by?

Answer 31

Binding mU & Kappa receptors

Question 32

Morphine is most commonly used in what species?

Answer 32

1. Dogs 2. Cats 3. Horses

Question 33

Morphine can be administered what route?

Answer 33

1. IV 2. IM 3. SC 4. Epidural 5. By Mouth

Question 34

Morphine side effects?

Answer 34

1. Dysphoria *Cats & Horses 2. Salivation 3. Vomiting 4. Defection 5. Panting *Dogs 6. Bradycardia 7. Colic in Horses 8. Respiratory Depression 9. Histamine Release *IV 10. Excessive sedation

Question 35

What opioid is prescribed when a strong pain relief is need that has a longer lasting affect?

Answer 35

Oxymorphone & Hydromorphone

Question 36

Oxymorphone & Hydromorphone bind with what receptors?

Answer 36

MU

Question 37

If you need to give a large dose of an opioid via IV what drug has a lower chance of a histamine release?

Answer 37

Oxymorphone & Hydromorphone

Question 38

Buprenorphine is a partial?

Answer 38

MU receptor agonist *Binds with the receptors but the effects aren’t as prominent as a drug that binds completely with the mU receptor

Question 39

Butorphanol is what type of receptor?

Answer 39

Kappa receptor agonist

Question 40

Butorphanol is used to?

Answer 40

reverse the mU receptor analgesia drug effects

Question 41

Ketamine is

Answer 41

◦ Dissociate Anesthetic ◦ Block the N-methyl-D-aspartate (NMDA) receptors that are in the spinal cord ◦ Used for animals experiencing chronic pain with no relief from other drugs ◦ Windup: Increased pain hypersensitivity ◦ Can be prescribed with opiods which will address the pain & the ketamine with prevent the maladaptive pain that can develope after a painful surgical procedure ◦ Administration ‣ SQ in small doses to chronic pain patients ‣ IV - CRI

Question 42

• Nonsteroidal Anti-Inflammatory Drugs (NSAIDS)

Answer 42

◦ Acts as an anti-inflammatory to help relieve pain & decrease inflammation ◦ All relieve somatic pain control ◦ Some visceral pain relief ◦ Adverse effects: ‣ GI issues ‣ Renal/Kidney issues ◦ Do NOT use in combination w/ glucocorticoids

Question 43

• Local Anesthetics ◦

Answer 43

Prevent transduction & transmission of pain impulses ◦ This is the only drugs that affects transmission of the nerve pain response/impulses ◦ Short duration of action - the affects do not last a long time ◦ Potential for toxicity with repeated doses ◦ Most commonly administered in clinic versus sending home

Question 44

• Alpha 2 Agonists •

Answer 44

◦ Provide good analgesia properties ◦ Use is limited by 3 factors: ‣ 1: Short duration of effect ‣ 2: Profound sedative effect ‣ 3: Potential adverse effects on the respiratory & Cardiovascular systems ◦ Best analgesia is through CRI in hospital ◦ Animals must have a healthy cardiovascular system before administration

Question 45

Tramadol ◦ •

Answer 45

Nonopiate drug ◦ Stimulates the mU receptor ◦ Decreased use in vet med due - as other drugs have greateer analgesia effects ‣ Study shows that it does not provide good analgesia in animals ◦ Administration: ‣ PO (By Mouth) for continuation of pain management at home

Question 46

Gabapentin

Answer 46

Mechanism of Action: ‣ Not well understood ‣ Appears to decrease secretion of excitatory neurotransmitters • Norepinephrine • Substance P ◦ Reduces windup pain ◦ Used for chronic pain management in dogs & cats ◦ Also used for refractory seizures & sedation in dogs & cats ◦ Used to treat arthritis ◦ Used in cats for spicy cats at vet visits ‣ 1 dose the night before & another dose 2-3 hours before appt ◦ Can be prescribed in Dogs but it’s more common to prescribe Trazodone ‣ Can prescribe Gabapentin & Trazodone to dogs for behavioral issue

Question 47

• Amantadine

Answer 47

A NMDA receptor antagonist similar to

Question 48

Ketamine

Answer 48

◦ Reduced windup pain ◦ Used for chronic pain management in dogs & cats

Question 49

Glucocorticoids

Answer 49

◦ Provide analgesia by reducing inflammation ◦ Do not use in combination with a n NSAID