Analgesia Flashcards
Pain is the _ vital sign
fourth
When pain elicits protective motor actions, what may the dog do?
try to bite after an IM injection
When pain elicits learned avoidance, what may it cause in the patient?
fear upon second visit to vet hospital
How may pain modify species behavior?
Different for individuals: seeking attention vs hiding
Untreated pain can affect
Behavior, Physiology, Metabolism, Immune system
What is nociception
detection by the nervous system for the potential for tissue injury
What does nociception protect the animal from?
painful or noxious stimuli
What is physiologic pain?
-Ouch pain
-Little or no tissue injury
-USEFUL: protects from injury
What is pathologic pain?
-follows tissue injury
-NO USEFUL FUNCTION: causes suffering
-Acute or chronic
Classifications of pathologic pain based on mechanism
Inflammatory, neuropathic, cancer, idiopathic
Classification of pathologic pain based on origin
Visceral (organs) or somatic (musculoskeletal- superficial vs deep )
Classifications of pathologic pain based on severity
none, mild, moderate, severe
What step of nociception is described?
Transformation of stimuli into sensory electrical signals (action potentials)
Step 1: transduction
What step of nociception is described?
Sensory impulses conducted to spinal cord
Step 2: transmission
What step of nociception is described?
Impulses are either amplified or suppressed
Step 3: modulation
What step of nociception is described?
Impulses are transmitted to the brain where they are processed and recognized
Step 4: perception
Drugs can be selected that will target specific receptors and block a specific step of nociception. _ _: targeting two or more of the receptors
Multimodal therapy
Why is multimodal therapy preferred?
reduces pain signaling by inhibition of multiple receptors and also allows lower drug dosages to be used, which decreases adverse effects and improves safety
What are the following consequences of?
-catabolism and muscle wasting
-immune system suppression
-inflammation and delayed wound healing
-anesthetic risk and increased anesthesia doses
-patient suffering
Untreated pain
Pathologic pain can result in
peripheral hypersensitivity or Primary Hyperalgesia
Primary hyperalgesia results from
tissue damage and constant stimulation of nerves (area close to the site of tissue injury becomes painful when stimulated with non-noxious stimuli)
What is secondary hyperalgesia
CNS hypersensitivity or windup
What drug can block secondary hyperalgesia
ketamine
What area is hypersensitive with secondary hyperalgesia
area further away from site of tissue injury (ex: you fracture your wrist and the forearm is touched)
What does secondary hyperalgesia result from
constant stimulation of spinal cord neurons (neurons become hyper excitable and sensitive)
Neuroendocrine changes: can results in a catabolic state and wasting, this looks like:
-ACTH release
-Elevated cortisol, norepi, and epi
-Decreased insulin
Sympathetic stimulation: can cause result in cardiac arrhythmias, this looks like:
-vasoconstriction
-increased myocardial work
-increased myocardial oxygen consumption
Pain elicits a _ response
stress (fight or flights)
The following describes _ _:
-Admin. of pain medications BEFORE pain occurs
-Commonly involves adding analgesic to premedication prior to anesthesia
-Reduces overall requirement for analgesia and duration of admin
-Prevents windup
Preemptive analgesia
What patients are less tolerant of pain
young