Anesthesia analgesia Flashcards
Epidural Meds: What is the onset of action, duration of analgesia +/- duration of motor inhibition for lidocaine
Dogs Onset: 4-6 min
Hrs analgesia: 1 hr
Motor: 60-120 min
Epidural Meds: What is the onset of action, duration of analgesia +/- duration of motor inhibition for 0.5% bupivicaine
Dogs Onset: 5-15 min
Hrs analgesia: >2 hr
Motor: 65-240 min
Epidural Meds: What is the onset of action, duration of analgesia +/- duration of motor inhibition for 0.75% ropivicaine
Dogs Onset: 7-15min
Hrs analgesia: 1.5-2.5 hr
Motor: 90-150 min
Epidural Meds: What is the onset of action, duration of analgesia +/- duration of motor inhibition morphine PF
Dogs Onset: 40-90 min
Hrs analgesia: 12-24
Epidural Meds: What is the onset of action, duration of analgesia +/- duration of motor inhibition buprenorphine
Dogs Onset: < 60 min
Hrs analgesia: >/= 24 hr
Epidural Meds: What is the onset of action, duration of analgesia +/- duration of motor inhibition dexmeitomidine
Dogs Onset: < 15 min
Hrs analgesia: 4.5 hrs
JAVMA 2017 What are fentanyl at 6 mcg/kg/hr and Lidocaine at 6 mg/kg/hr effects of sevoflurane in dogs
alone or in combination reduce MAC
JAVMA 2017 What effect did hypotension during hemilamenectomy have out outcome post operatively
Did not have any effect on motor function or urinary continence
JAVMA 2017 What effect did transdermal lidocaine patchs have on OVH dogs
No additional benifit to morphine and carprofen in OVH
Not systemically absorbed
JAVMA 2017 What is the anesthetic death rate in cats/dogs
Cats: 11/10,000
Dogs 5/10,000
JAVMA 2017 What increased the risk of death in dogs and cats during anesthesia
Both: increased age, non elective procedures
Dogs: Exam not recorded (267 x) Abnormal HCT (5.5 x)
Cats: Absent SPO2 (34 x)
Under weight dogs 15 x more likely to die
2017 JAVMA In a multideminsenial composite pain score what percent disagreement for those that needed rescue analgesia
6.1%
JVECC 2017 What increased risk of GER
Intrabdominal surgery, change in body position, increased length of anesthesia
JVECC 2017 What increased risk of post anesthesia vomiting
Change in ventilation mode during anesthesia, length of anesthesia, synthetic colloid to tx hypotension
JVECC 2017 What increased risk of post anesthesia diarrhea- univariate model
increased length of anesthesia, change in ventilation mode, hypoxemia
JAVMA 2017 What if any benefit did diphenhydramine have prior to MCT excision
No CV or respiratory benefit over placebo in isoflurane dogs
JVIM 2017 What effect did Omeprazole have after two doses prior to anesthesia in cats
Increased gastric and esophageal pH
Had 33% of GER during anesthesia
What is the MOA of Robenocoxib and potential benifits
Selective Cox-2 inhibitor; cleared from central body compartment but remains in inflamed tissues
What is the nocecptive pathway
Transduction: noxious stimuli at the periphery
Transmission of stimulus to the dorsal horn of the spinal cord
Modulation / central integration of the signal at the CNS level
Projection to the brain via the spinothalmic tracts
Perception
What do A beta nerve fibers do
Touch, hair movement- myelin
What do A delta type I fibers do
‘first pain’ prick, Higher heat threshold
Thin myelin
What do A delta type II fibers do
Pain due to heat
Think myelin
What do C fibers do
slow pain
no myelin
What is the MOA of gabapentin
Gaba analogue
Voltage gated calcium channels on excitatory neuros
What is the MOA of tramadol
Weak mu opiod effects, norepinephrine and sterotonin reuptake inhibition and binding of alpha 2 adrenergic receptors in the pain pathway
Amantadine MOA
Modulates CNS dopamine
NMDSA antagonist
Amitriptyline MOA
Tricyclic antidepressant by inhibiting reuptake of the neurotransmitters serotonin norepinephrine and to lesser extent dopamine
Flupirtine MOA– Not available in U.S.
amino pyridine drug classified as a selective neuronal potassium channel opener
G-protein regulate inwardly rectyfing K+ channels
Indirectly inhibits NMDA
Tapentadol MOA
Morphine (mu opoid receptor) agonist and noradrenaline reuptake inhibitor. In people less mu by 50x but more potent for pain due to 2 mechanisms of action. Orally absorbed well.
Maorpitant for pain MOA
Selective neurokinin-1 receptor antagonist
Substance P shares NK-1 receptor
Buprenorphine MOA
Partial Mu agonist
Butorphanol MOA
Kappa agonist; Mu antagonist
Fentanyl MOA and what others others
Mu agonist
oxymorhone, methadone, remifentanyl, hydromorphone
Methadone MOA
Mu agonist
Also reported to be NMDA antagonist and alpha 2 antagonist
Morphine MOA
Mu and delta agonist
Naloxone MOA
Kappa and Mu antagonist
How do opioids cause respiratory depression
Have does dependent increase in PaCO2 due to decrease in minute volume
What are some negative effects (potential positive in some cases) of opioids
Suppress cough reflex Respiratory depression Dogs- reset thermoregulatory center Opioid incuded hyperalgesia (more painful with increasing doses) Urine retention Bradycardia Vomiting, nausea, defecation Morphine rapid IV- histamine release
Ketamine MOA
NMDA receptor antagonist: disscoative anesthetic
What are three benefits to ketamine for pain
Reduce acute somatic and visceral pain
improve opioid sparing, prevent opioid tolerance
May reduce pro-inflammatory cytokines
Lacks cardiorespiratory depression
Propofol MOA
Hypnotic agent: positive modulation of the inhibitory function of the neurotransmitter GABA through GABA-a receptors
What are negative side effects of propofol
Dose dependent
vasodilation, respiratory depression, decreased cardiac output
Aflaxalone MOA
Neurosteroid that enhances the actions of GABAa
What are the negative side effects of alfaxalone
May cause less (but still some) vasodilation and Decrease in CO compared to propofol
What are negative side effects of ketamine
Myclonous, dysphoria, increased ICP, pain at injection site
Which patients should you avoid Ketamine
where increased contractility and HR may be determintal such as HCM and tachyarrhythmias
JAVMA 2018 What is the increased risk associated with brachycephalics and anesthesia
1.57 x more likely for perianesthetic and 4 x more likely for post anesthetic complications
Every 30 minutes of anesthesia increase 18% of perianesthetic complications
Complications decrease 2% of complications with every 1 kg increase in body weight
Vet Journal 2018 What effect of did a lose dose (0.5 mcg/kg/hr) have on CV during anesthesia
Had minimal effect on HR and BP with no clear benefit.
Loading dose did decrease heart rate by 25% so authors recommended to consider loading over longer time 10-15 min
What is a TAP block
Transversus abdominal plane block
Between obliqous internus abdominal muscle and transversus adominous muscle
Where the ventral nerve branches of T 10, 11, 12 run
5 cm lateral from mid line at subcostl site and mid abdominal site on each side. 0.25 ml/kg per site dilute if needed to get larger volume
Define central sensitization
increase in excitability of neurons in the central nociceptive pathways to normal or subthreshold input
Manifests as altered pain sensitivity
How does norepinephrine work in the descending pain pathway
modulates nociception via alpha 2 receptor
How does seritonin 5-HT work in the descending pain pathway
involved in descending modulation
How does dopamine work in the descending pain pathway
inhibiting nociception
How does Mg work in the descending pain pathway
NMDA receptor antagonist
Mediated reduction in IL-6 and TNF Alpha
Not recommended for pain
AJVR 2018 Which opioid in addition to dexmeditomidine was best for sedation and noception
Sedation: mepiridone and methadone
Noceptive: butorphanol, methadone, morphine, nalbuphine
0.5 mg/kg doses
2018 AJVR Was there a benefit for 0.4 Fio2 with nitrogen over > 0.9 Fio2 for dogs undergoing OVH
No observed benifit
2018 AJVR What was noted about laryngeal block and intratesticular block with lidocaine
Both have additive affect to total dose in cats.
Should aim to give a total dose of less than 5 mg/kg
2018 AJVR How long is it recommended to store perservative free alfaxalone
7 days with a closed system transfer device and refrigerator.
JAVMA 2018 Tramadol at 5 mg/kg q 8 hrs was it a benifit for OA
No clinical benifit
JAVMA 2018 Tramadol for cats at what dose improved activity scores in geriatic OA cats
2 mg/kg. higher doses resulted in side effects of euphoria, dysphoria sedation and decreased appetite.
2019 AJVR In cats under isoflurane anesthesia with dexmed sedation what effect did atipamizole have
at 1/2 or full dose it was ineffective to increase HR and CO but did result in lower MAP than compared to saline
AJVR 2019 what was the MOA proposed for the reason that atipamizole does not alter CO or HR in isolfurane anesthized cats with dexmed sedation
Inhalant anesthetics ability to mute baroreflexes
AJVR 2019 What effect was noted in dogs give Gabapentin 20 mg/kg 2 hrs prior to anesthesia
Isoflurane MAC sparring with no effect on hemodynamic and vital variables
AJVR 2019 What was the bioavailability of naloxone via an atomizer
32% effectiveness is unknown
JAVMA 2019 Greyhounds with repeated HyperK
Resolves post anesthesia.. Noted on ECG
JAVMA 2019 How does the charcoal air filtration position alter waste anesthetic gas
Low did not matter position
High (1 L/min O2 @ 5% vaporizer) all canisters in horizontal position than vertical
What is the ocular cardiac reflex
manipulations of the eye or increase interocular pressure result in bradycardia
2019 JAVMA What resulted in less ocular cardiac reflex during enucleation
retrobulbar nerve block decreased prevalence but not anticholergic drugs during enucleation
2019 JAVMA What provided additional pain management to carprofen with enucleation
absorable gelatin hemostatic sponge soaked in 1% ropivicaine
AJVR 2019 What was noted with sedation and duration with 20 mcg/kg of injectable dexmeditomidine given oral transmucosal
Resulted in similar sedation and prolonged duration despite bioavailability of 11%
What is the MOA of vitinoxan
alpha 2 antagonist in periphry as does not cross BB
2019 AJVR what was the effect of metidomidine in dogs with vitinoxan administered atipamazole
atipamiazole falied to restore HR and cardiac index in metitomidine only dogs but did in the vit+met
