Intro to pain management (Granone)

Question 1

Goals and Objectives

Answer 1

• Understand pain pathophysiology and its effects
• Discuss types of pain and pain pathway
• Become familiar with methods for recognizing pain in veterinary patients
• Become familiar with the assessment of pain in veterinary patients

Question 2

Negative consequences of pain

Answer 2

• behavioral
• physiological
• neurohumoral
• metabolic
• immunological

Question 3

Definition of pain

(physiology of pain)

Answer 3

• An unpleasant sensory and emotional experience with actual or potential tissue damange

Question 4

Primary afferent nerve fibers

Answer 4

Information sent to brain

Question 5

Sensory afferent nerve fibers

Answer 5

• Dedicated to response of noxious stimuli

Question 6

Protective response

Answer 6

Withdrawal from stimuli

Question 7

Nociception

Answer 7

• Detection of potential or actual damaging stimuli and transmission of information to the brain

Question 8

5 processes of nociception

Answer 8

• transduction
• transmission: to dorsal horn of spinal cord
• modulation
• projection: by afferent neurons
• perception

Question 9

Nociceptors

Answer 9

• nerve ell endings, initiate the sensation of pain, transduce electrical signals at site of tissue disruption

Question 10

Activation of nociceptors by

Answer 10

• heat
• cold
• chemical
• mechanical stimuli

Question 11

Dorsal horn receives electrical signals from primary sensory nerve fibers

Answer 11

• alpha-beta fibers
• alpha-gamma fibers
• c fibers

Question 12

Brain

(physiology of pain)

Answer 12

• signals received => physiologic and behavioral responses initiated

Question 13

Hyperalgesia

Answer 13

• increase in painfulness of noxious stimuli, reduced pain threshold
• inflammation => hyperexcitability due to reduction in threshold => inc responsiveness = peripheral sensitization

Question 14

Allodynia

Answer 14

• pain following non-painful stimuli
• peripheral nerve and tissue injury => change in CNS
• central sensitization

Question 15

Windup pain

Answer 15

• perceived increase in pain intensity over time
  
  • repeated delivery of painful stimulus
• frequency dependent increase in excitability of spinal cord neurons => afferent C fibers
• Difficult to treat

Question 16

Somatic pain

Answer 16

• related to wall of body cavity
  
  • musculoskeletal pain

Question 17

Visceral pain

Answer 17

• poorly localized
• mechanical stimuli (stretching of viscera)
• Ischemia
• Chemical and thermal stimuli
• Change in somatic muscle tone, autonomic responses

Question 18

Recognition of pain

Answer 18

• challenging aspect of pain management
• owner info regarding behavior changes
• no single parameter pathonomonic for pain
• may be masked in unfamiliar situations
• acute vs. chronic

Question 19

equine pain exhibition

Answer 19

• draught horses more stoic
• foals and young horses more likely to exhibit pain
• owner/handler may be good source of info

Question 20

Indicators of pain, stress and well-being

Answer 20

• attitude
• behavior
• posture
• activity
• appearance
• appetite

Question 21

indicators of pain, stress and well-being in horses

Answer 21

normal factors plus

• facial expression
• interaction with people
• response to handling
• willingness to perform work

Question 22

classic sign of thoracic pain in a cow

Answer 22

head extended

Question 23

objective pain assessment

Answer 23

• HR, RR, BP, rectal temp
  
  • weak correlation between inc HR and pain
• Plasma cortisol, catecholamine and beta-endorphin concentrations
  
  • variability between concentration and marker of pain

*all of these are non-specific combine with other tools

Question 24

Categories of pain scales

Answer 24

• simple descriptive pain scale
• numerical rating scales
• composite pain scoring scales

Question 25

Simple descriptive pain scale

Answer 25

• mild, moderate, severe pain
• very basic tool, not validated

Question 26

Numerical rating scales

Answer 26

• numerica units assigned to different categories of behaviors

Question 27

therapeutic pain managment

Answer 27

• preemptive analgesia
  
  • provide analgesia prior to noxious stimuli
  • decrease drug requirements during maintenance and recovery of anesthesia
• multimodal analgesia
  
  • use of more than one modalit of analgesia to obtain additive or syndergistic effects
  • reduction in the dose of each drug used

Question 28

Pharmaceutical pain management

Answer 28

• NSAIDS
• Opiods
• local anesthetics
• a₂ agonists
  
  • xylzine
  • dexmetatomidine

Question 29

Therapeutic pain managment

Answer 29

• pharmaceutical
  
  • NSAIDS
  • opioids
  • local anesthetics
  • alpha 2 agonists
• Nutritional-nutraceutical (lack of clinical studies)
  
  • glucosamine
  • chondroitin sulfate
• Complimentary therpies
  
  • acupuncture
  • chiropractic
  • physical
  • ultrasound

Question 30

Summary

Answer 30

• pain is a multi-faceted complex experience
• no single parameter pathognomonic for pain
• multiple tools to help with assessment of pain and the therapeutic approach
• protocol should include preemtive and multimodal therapeutics when possible
• responsibility to strive to alleviate pain