Intro to Pain Management

Question 1

negative consequences of pain

Answer 1

• hyperalgesia
• sympathetic stimulation
• decreased appetite
• increased anesthetic drug requirements
• serious behavioral, nuerohumoral, metabolic and immunological effects
• unseen changes to CNS

Question 2

definition of pain

Answer 2

an unpleasant sensory and emotional experience with actual or potential tissue damage

Question 3

how is pain perceived

Answer 3

• throughout CNS, primary afferent nerve fibers provide info to the higher centers of the brain
• most animals have sensory afferent nerve fibers that respond to noxious stimuli
• protective means for reflexive withdrawal to noxious stimuli

Question 4

adaptive pain-inflammatory

Answer 4

spontaneous pain and hypersensitivity to pain in response to tissue damage and inflammation

occurs with tissue trauma, injury, surgery

Question 5

adaptive pain-nociceptive

Answer 5

transient pain in response to noxious stimulus

small aches and pains that are relatively innocuous and that protect the body from the environment

Question 6

allodynia

Answer 6

• pain caused by a stimulus that does not normally result in pain
• manifestation of peripheral nerve and tissue injury that induces changes in CNS

Question 7

analgesia

Answer 7

absence of pain in response to stimulation that would normally be painful

Question 8

anesthesia

Answer 8

medically induced insensitivity to pain

the procedure may render the patient unconscious (general anesthesia) or consist of local anesthesia

Question 9

dysphoria

Answer 9

a state of anxiety or restlessness, often accompanied by vocalization

Question 10

hyperalgesia

Answer 10

• an increased response to a stimulus that is normally painful and reduced threshold for pain

Question 11

maladaptive pain-neuropathic

Answer 11

spontaneous pain and hypersensitivity to pain in association with damage to or a lesion of the nervous system

Question 12

maladaptive pain-central neuropathic pain

Answer 12

pain initiated or caused by a primary lesion or dysfunction in the CNS

“central pain”

Question 13

multimodal analgesia

Answer 13

use of more than one drug with different actions to produce optimal analgesia

Question 14

peripheral neuropathic pain

Answer 14

pain initiated or caused by a primary lesion or dysfunction in the peripheral nervous system

Question 15

preemptive analgesia

Answer 15

administration of an analgesic before painful stimulation

Question 16

wind-up pain

Answer 16

• perceived increase in pain intensity over time when a painful stimulus is repeatedly delivered above a critical rate
• frequency dependent increase in excitability of spinal cord neurons (afferent C fibers) - central sensitization

Question 17

nociception

Answer 17

• process of detection of potentially or actually damaging stimuli and the transmission of that information to the brain
• includes five processes:
  
  • transduction, transmission, modulation, projection, perception

Question 18

transduction

Answer 18

the conversion of noxious stimuli to an AP at the level of the nociceptors

Question 19

transmission

Answer 19

the propagation of APs by primary afferent neurons to the spinal cord

Question 20

modulation

Answer 20

process by which nociceptive info is augmented or inhibited

Question 21

projection

Answer 21

delivery of nociceptive information from the spinal cord to the brain

Question 22

perception

Answer 22

integration of the nociceptive information by the brain

overall conscious emotional experience of pain

Question 23

nociceptors

Answer 23

unspecialized nerve cell endings that initiate the sensation of pain, sense and transduce electrical signals at the site of tissue disruption

Question 24

nociceptive afferents

Answer 24

• transmitted to the dorsal horn of the spinal cord via primary sensory A-beta, A-gamma and c nerve fibers
• respond to heat, cold, mechanical and chemical stimuli

Question 25

peripheral sensitization

Answer 25

**localized inflammation** at site of tissue injury, in **peripheral tissues**, causes **hyperexcitability** of nociceptors due to a reduction in threshold and an increased responsiveness to noxious stimuli

Question 26

chronic pain

Answer 26

pain which **lasts beyond the expected time** period of healing

Question 27

acute pain

Answer 27

usually **temporary** and has a **specific causes** such as surgery, injury or infection

Question 28

painful chemical/physical stimuli to APs

Answer 28

* **sensory pain receptors** located on **peripheral ends** of sensory nerve fibers **convert painful chemical or physical stimuli in APs** * these APs cause **gated ion channels to open** causing an **influx of Na or Ca ions to diffuse** **across a diffusion gradient** leading to **depolarization** of cell membrane and an AP * pain receptors **respond to stimuli** that have the **potential to cause cell damage**

Question 29

release of inflammatory mediators leads to peripheral sensitization by three main mechanisms:

Answer 29

1. **depolarization** of pain sensing nerve endings 2. **lowering the threshold** in which depolarization occurs in primary afferent nerves 3. **vasodilation and increased permeability** of blood vessels that results in an **increased number of leukocytes and inflammatory mediators** at site of injury

Question 30

somatosensory cortex is responsible for:

Answer 30

1. **discrimination** of pain signals 2. **recognition**, **learning** and **memory** of painful experiences

Question 31

somatic pain

Answer 31

pain related to the **wall of the body cavity** musculoskeletal

Question 32

visceral pain

Answer 32

pain that is often **poorly localized** and associated with **mechanical/chemical/thermal stimuli or ischemia** accompanied by **changes in somatic muscle tone and autonomic responses**

Question 33

assessing pain in cats

Answer 33

* **posture**, **orientation** in a cage, **facial expression**, **loss of normal behaviors** and **response to palpation** of a surgical site should be evaluated

Question 34

simple descriptive pain scales

Answer 34

* first pain scales to be used in animals * **3 to 5 point scale** with answers ranging from **mild, moderate to severe** * very basic and not validated

Question 35

University of Melbourne Pain Scale

Answer 35

* **numerical rating scale** * assesses **different behavioral and physiological indices** to categorize pain **after surgery in dogs**

Question 36

Colorado State University canine and feline acute pain scales

Answer 36

* **numerical pain scales** * used **clinically** * may fail to capture the **full details of a case**

Question 37

visual analog scale (VAS)

Answer 37

* designed to **improve assessment** by trying to **capture the subtle nuances of pain** that may go unrecognized with the use of other scales * **semi-objective scale** that consists of a **100 mm horizontal line** that represents the **painfulness of a patient** (no pain-0, worst pain possible-100) * very **simple to use** and provides assessor info on **trends** in patient's pain level and treatment * prone to observer **variability and bias**

Question 38

Glasgow University Veterinary School

Answer 38

* **composite pain scoring system** for pain assessment in dogs * **validated and reliable** * **questionnaire** that examines n**umerous behavioral traits** and then a pain score is derived * **six categories and 30 descriptors** on the form * descriptors are **ranked numerically** within each category according to pain severity

Question 39

preemptive perioperative analgesic administration

Answer 39

should be instituted **before surgery and application of noxious stimuli** benefit of **decreased drug requirement** during maintenance and recovery of anesthesia

Question 40

multimodal therapeutic plan

Answer 40

should be instituted and includes the use of drugs that are **directed at treating specific mechanisms of pain** allows for **reduction in the dose** of each drug used while also **reducing potential side effects or toxicity**