Ch.24 Equine Pain Management Flashcards
a. Pain causes decreased release of adrenocorticotropic hormone ACTH, cortisol, renin
b. neurotransmitters involved in descending excitatory pathways include glutamate, norepinephrine, serotonin, γ-aminobutyric acid (GABA), and endogenous opioids
c. Pain is perceived by the animal when the signals reach the somatosensory cortex
d. Pain is perceived by the animal when the signals reach the periaqueductal grey matter
c. Pain is perceived by the animal when the signals reach the somatosensory cortex
Pain stimulates neuroendocrine responses, namely
increased sympathetic outflow from the spinal cord
increased release of hormones;
adrenocorticotropic hormone ACTH
cortisol
Renin
and decreased release of
insulin
Testosterone
neurotransmitters involved in descending inhibitory pathways include glutamate, norepinephrine, serotonin, γ-aminobutyric acid (GABA), and endogenous opioids
Descending pathways originate in the brain within periaqueductal grey matter and the ventromedial medulla
Which of the following statements is true regarding acute pain
a. Nociceptors transduce and encode noxious stimuli and send impulses to the ventral horn of the spinal cord via small myelinated Aδ, and thinly and nonmyelinated C afferent nerve fibers
b. Nociceptors transduce and encode noxious stimuli and send impulses to the dorsal horn of the spinal cord via small myelinated Aδ, and thinly and nonmyelinated C afferent nerve fibers
c. Nociceptors transduce and encode noxious stimuli and send impulses to the dorsal horn of the spinal cord via large myelinated Aδ, and thinly and nonmyelinated C afferent nerve fibers.
d. Nociceptors transduce and encode noxious stimuli and send impulses to the dorsal horn of the spinal cord via small myelinated C, and thinly and nonmyelinated Aδ afferent nerve fibers.
b. Nociceptors send impulses to the dorsal horn of the spinal cord via small myelinated (Aδ), and thinly and nonmyelinated (c) afferent nerve fibers.
Which of the following statements is true regarding the mechanism of acute pain ?
a. After reaching the dorsal horn of the spinal cord,
the Aδ and C fibers from superficial pain pathways
are transmitted via the spinocervicothalamic tract
b. After reaching the dorsal horn of the spinal cord,
the Aδ and C fibers from superficial pain pathways
are transmitted via the spinoreticular tract
c. After reaching the dorsal horn of the spinal cord,
the Aδ and C fibers from deep pain pathways
are transmitted via the spinocervicothalamic tract
d. After reaching the ventral horn of the spinal cord,
the Aδ and C fibers from superficial pain pathways
are transmitted via the spinocervicothalamic tract
a. After reaching the dorsal horn of the spinal cord,
the Aδ and C fibers from superficial pain pathways e.g., somatic structures, such as skin
are transmitted via the spinocervicothalamic tract
whereas those from the deep pain pathways e.g., viscera and periosteum
are transmitted via the spinoreticular tract.
Impulses from noxious stimuli
superficial
A-myelinated C-non or thinly myelinated afferent nerve fibres
Dorsal horn of spinal cord
*Spinocervicothalmic tract - superficial
Spinoreticular tract - deep pain
Somatosensory cortex - pain is felt
Prolonged stimulation of the pain pathways can result in?
a. Increased testosterone
b. Decreased cortisol
c. Peripheral sensitization - allodynia
d. Central desensitization
c. Peripheral sensitization - allodynia
Pain causes decreased testosterone and insulin
increased ACTH, Cortisol and Renin
prolonged stimulation of the pain pathways can result in peripheral and central sensitization. Inflam mediators prostaglandins, bradykinin, substance p, histamine, H ions, cause direct stim of nociceptors or make them more sensitive
Whichof the following statements is correct?
a. N-methyl-d-aspartate (NMDA) receptor stimulation by the neurotransmitter glutamate is thought to be responsible for hyperalgesia
b. Peripheral sensitization plays an important role in chronic pain
c. Excitement and locomotor stimulation are frequently observed when opioids are administered to horses undergoing surgery or in combinations with sedatives
d. Butorphanol is a synthetic opioid, which is thought to act as an antgonist at κ-receptors and an agonist at μ-receptors.
a. N-methyl-d-aspartate (NMDA) receptor stimulation by the neurotransmitter glutamate is thought to be responsible for hyperalgesia
Central sensitization plays an important role in chronic pain
excitement and locomotor stimulation are rarely observed when opioids are administered to horses undergoing surgery or in combinations with sedatives
butorphanol is a synthetic opioid, which is thought to act as an agonist at κ-receptors and an antagonist at μ-receptors.
a. Butorphanol is a synthetic opioid, which is thought to act as an antagonist at κ-receptors and an agonist at μ-receptors.
b. Butorphanol dosage recommended for analgesia (0.1 mg/ kg) is approximately twice that recommended for sedation
c. Analgesic duration of action of Butorphanol is short 30-60mins
d. Buprenorphine, is a μ-antagonist and κ-agonist opioid
c. Analgesic duration of action of Butorphanol is short 30-60mins
Butorphanol is a synthetic opioid, which is thought to act as an agonist at κ-receptors and an antagonist at μ-receptors.
Butorphanol dosage recommended for analgesia (0.1 mg/ kg) is approximately 5 to 10 times that recommended for sedation
Buprenorphine, a μ-agonist and κ-antagonist opioid,
Which of the following statements is true?
a. The analgesic effects of butorphanol outlast those of buprenorphine
b. Fentanyl is a mu antagonist
c. Morphine is a mu antagonist
d. The sedative effects of α2-agonists usually outlast the analgesic effects
d. The sedative effects of α2-agonists usually outlast the analgesic effects
Buprenorphine 7-11 hrs, butorphanol 30-60mins
Fentanyl and morphine are mu agonists
Which of these statements is correct in relation to the horse?
a. Higher doses of Alpha-2 agonists are necessary to produce analgesia when used as in an epidural than when given IV
b. The skin, muscles, and peritoneum of the flank region are desensitized by anesthesia of the dorsal and ventral branches of the 13th thoracic and first and second lumbar spinal nerves.
c. Ketamine is an NMDA receptor agonist
d. High concentrations of ketamine may block sodium channels
d. High concentrations of ketamine may block sodium channels
Lower doses of Alpha-2 agonists cause analgesia when used as in an epidural than when given IV
The skin, muscles, and peritoneum of the flank region are desensitized by anesthesia of the dorsal and ventral branches of the 18th thoracic and first and second lumbar spinal nerves. (13th is bovine)
Ketamine is an NMDA receptor antagonist
Which of the following statements is true?
a. Gabapentin is thought to modulate the activity of presynaptic voltage-gated calcium channels
b. Gabapentin does not act specifically as an analgesic but can reduce established hyperalgesia
c. The plasma elimination half-life of Gabapentin following a dosage of 5 mg/kg orally is 3.4 hours
d. all of the above
d. all of the above
Opioid receptors are present in equine synovial membranes
Effects of 0.05-0.1mg/kg intra-articular morphine are 20-24 hours
Opioid receptors are present in equine synovial membranes
Effects of 0.05-0.1mg/kg intra-articular morphine are 20-24 hours
Which of the following statements is correct?
a. Caudal epidurals carry an increased risk for inadvertent dural puncture when compared to cranial epidurals
b. Epidural volume should be limited to 4-5cc in a 500kg horse
c. The preservative benzethonium chloride should be avoided in epidural medication as it is neurotoxic
d. all of the above
c. The preservative benzethonium chloride should be avoided in epidural medication as it is neurotoxic
Cranial epidurals carry an increased risk for inadvertent dural puncture
Epidural volume should be limited to 9-10cc in a 500kg horse
What receptors does Buprenorphine work on
Kappa antagonist
Mu agonist
Dose of Buprenorphine
10ug/kg/iv
Dose for transdermal fentanyl
2-3 10mg patches on a 500kg horse
What is the only drug used for tx or prevention of central sensitisation which has marketing authorisation for use in horses
Ketamine
