Jr. Sx - Anesthesia Must Know 2

isabellepjk's version from 2018-09-08 21:10


Question Answer
MOA?Blocks D2 receptors (sedative effect) & Blocks α1 adrenoceptors (vasodilation, hypotension)
IV ace onset of action?Up to 20min
Routes of admin for ace?IV/IM/PO/SQ
IM/SC ace onset of action?Up to 45min
How is ace metabolized?Liver
How long is Ace's duration of action?LONG!!! 4-6 hours (longest acting)
Does ace make them vomit?No, it's anti-emetic
What condition might make you think twice about using ace?Might dec seizure threshold
How does ace affect BP?The antagonism of the α1 receptors means there is VASODILATION which DEC BP (so dont use in shocky or dehydrated PTxs)
What should you know about ACE'S effects on the PCV?DONT USE if PCV is low - czs erythrocytes to be sequestered in the spleen
What is a pos affect ace has on the heart?Stabilizes heart against catecholamine induced arrhythmias
If the animal is super excitable or hyper, what might you want to consider w/ ACE?Epinephrine reversal: paradoxical vasodilation w/ epinephrine
Should you admin epinephrine w/ ace?No... will cz MORE vasodilation (bc ace is taking up the α 1s, so epi goes to Beta 2s, which czs more vasodilation)
Which breed should you look out for w/ ace?Boxers
How does ace affect the HR?Stays the same or slight inc
Overall how does ace affect the CV system?Same/inc HR
Dec BP
How does ace affect their temp regulation?Poikilothermia (loss of normal thermal regulation) so yay bearhuggers!
How does ace affect blood clotting?Inhibits platelet aggregation (so don't give if already low platelets)
ACE is usually given in combo with..Opioids
Bleeding disorders/platelet probs
Shocky animals
How does ace affect resp system?Minimal effects
What group of drugs does ace belong to?Phenothiazines
Will ace cz an allergic rxn?No, actually anti-histamine effects


Question Answer
Why don't we like the α agonists?All the nasty heart things
MOA of Dexmedetomidine?Alpha 2 AGONISTS. (also does some α-1 agonism)
How does Dexmedetomidine affect BVs/BP?VasoCONSTRICTION at 1st, & then a dec in BP from there
How does Dex affect HR? Rhythm?Bradycardia (reflex from vasoconstriction, & also bc dec sympathetic tone & inc vagal tone)...czs bradyarrhythmias (1st & 2nd degree AV block)
Does Dex make them vomit?Yes, can induce emesis
How does Dex affect the resp system?Resp depression at higher doses
How does Dex affect CO?Dec it :(
How does Dex affect blood glucose?Inhibition of insulin release → hyperglycemia
Antagonist?Atipamezole (equal volume to reverse - note, reverses analgesia too)


Question Answer
MOA of Morphine?Full Mu agonist
Analgesia?YES. All of the analgesia
How does Morphine affect emesis?Morphine czs vomiting (esp when admin preemptively)
What should you know about IV Morphine?Can cz histamine release - DO NOT IV QUICKLY (can lead to hypotension & reflex tachycardia)
How does Morphine affect the CV system?Minimal affects
Even though opioids are usually for analgesia, why do we use them w/ premeds often?Potentiate effects of premeds
What are the major effects of the Mu receptor?Analgesia
Resp depression
Inhibits GIT
How does Morphine affect the resp system?Dose dependent resp depression
How does Morphine affect temperature of PTx?HYPOTHERMIA for dogs (hyperthermia in cats)
How does Morphine affect pupil size?MIOSIS in dogs (mydriasis in cats...bc cats)
Is there antagonist?YES! Naloxone/Naltrexone
How is Morphine metabolized?Liver


Question Answer
What kinda drug is Atropine?Anti-cholinergic
MOA of Atropine?(Anticholinergic) Block the AcH receptors in the PARASYMPATHETIC nervous system (so rest & digest doesnt work → more fight or flight)
How does Atropine affect HR?Inc
How does Atropine affect the gut?Dec motility
How does Atropine affect the resp system?Relax bronchioles (get more air)
How will Atropine affect the pupils?Dilate (upper = dilated pupils)
When is the only time Atropine is effective in Tx bradycardia?Only Tx bradycardia czs by vagal stimulation
Does Atropine affect the CNS?YES!! Can cross BBB (and placenta!)
Do you want to dose Atropine cautiously?Actually, give HIGH END of dose bc initially czs a DEC in HR (followed by an inc)'
When do you want to give Atropine?When there is dec HR & dec BP together
How long is the duration of action on the heart for Atropine?About 20min


Question Answer
MOA of Propofol?Interaction at GABA-A receptor (agonist)
Onset of action for Propofol?30 sec (FAST)
Duration of action for Propofol?10min
Metabolism/excretion of Propofol?Metabolized by liver (glucoronidation) Excreted by kidney...there is minimal accumulation (might contribute to short duration of action)
How does Propofol affect BP?HYPOTENSION
How does Propofol affect the resp system?RESP DEPRESSION & APNEA!!!!
What things should you be mindful of when you start to inject Propofol?might have apnea, might have excitatory signs (like paddling)
In what manner should you inject Propofol?SLOWLY inject to effect
Contraindications of Propofol?NO hypovolemic PTxs (bc czs hypotension)
No PTxs in heart failure (dec BP & dec breathing)
Which conditions should make you avoid giving Propofol?Lipid Dz like hyperlipidemia/ pancreatitis (bc lipid emulsion formula)


Question Answer
MOA?Neuroactive steroid that potentiates GABA-a receptors (provides hypnosis & mm relaxation)
How can you admin Alfaxolone?IV/IM
Metabolized? Excreted?Metabolized in liver & excreted in bile
How much accumulation of Alfaxalone?Minimal :) good for CRI
How does Alfaxalone affect the resp system?Minimal respiratory changes (dose & injxn rate dependent!) [Can cz apnea if fast admin]
How does Alfaxalone affect the CV system?Hypotension (mainly by myocardial depression) → reflex tachycardia
Analgesia?No (?)
How should you admin Alfaxalone?SLOW injxn & induction of dose (over 60sec)


Question Answer
Conc of iso needed for ANx?1.5% (this is why we need a vaporizer- - bc at standard temp & pressure it is in the air at a conc of 32%)
What is the MAC?Minimum alveolar concentration (standard index of potency)
What is the MAC of iso?1.3% - 1.6% - very potent! (& higher oil:gas PC)
How does iso affect the resp system?Resp depressant
How does iso affect BP?Dec
How does a low CO affect iso's effects?Low CO → inc time for blood:gas → faster diffusion into blood (and then has a high oil:gas so is potent)
How much of iso is metabolized?<1%
How does iso affect the CV?Dose dependent depression

Carprofen + Meloxicam

Question Answer
MOA for Carprofen?COX2 selective in dogs
Diff btwn COX1 & COX2?COX1 is the housekeeping COX (help w/ platelet aggregation, renal blood flow, protect GI mucosa)
COX2 is the cox that...(induced as a response to tissue damage, facilitates the inflammatory process. might lead to platelet aggregation, vasoconstriction, thromboembolism)
Adverse effects of NSAIDs?Irritate/ulcerate GI
Platelet dysfnxn & prolonged bleeding
Impair renal fnxn due to dec blood flow bc hypotension
How do NSAIDS affect the resp?Dont
How do NSAIDS affect the CV?(Only cz hypotension in renal blood flow, she says no CV side effects...note platelet dysfnxn)
You should avoid NSAIDs if what 2 organs arent doing well?Liver & kidney
Avoid NSAIDs if what is going on w/ your blood volume?Avoid if hypovolemia/dehydration
If your PTx has low platelets, should you be concerned w/ your NSAIDs?Yes - bc cz coagulopathies
How is Meloxicam metabolized/excreted?Liver meta, & fecal excretion
Does Meloxicam affect COX 1 or COX 2 more?COX2 selective
What drug shouldnt you combine NSAIDs with?NOT WITH STEROIDS (inc acid production & inhibit cox so dec mucus production → ulcers)
Carprofen has what 3 properties?Analgesic
Carprofen metabolized where?Liver
Meloxicam has what 3 properties?Analgesic

Local anesthetics (Lidocaine & Bupivacaine)

Question Answer
How do LAs affect the BVs?VasoDILATION
What is the MOA for local anesthetics?BLOCK Na+ channels, which blocks propagation of APs along the nerve
Why might you want to add epi to your LA?Czs vasoconstriction → Inc duration of action
What type of LAs are Lidocaine & Bupivacaine?AMIDES
How are amide LAs metabolized & excreted?Metabolized via liver, excreted via kidney
What are the toxicities/systems affected by tox of LAs?Neurotox & cardiotox (Bupivacaine)
Which is the cardiotox one?Bupivacaine (vasodilation)
Onset of Lidocaine? Duration?Faster onset (3-5min)...duration of 1-2 hours (so shorter duration also)
Onset of Bupivacaine? Duration?Longer onset (20min)...duration of 3-8 hrs (longer duration w/ longer onset)
Which is more potent - Lidocaine or Bupivacaine?Bupivacaine (bc more lipophilic)
Which is faster to work - Lidocaine or Bupivacaine?Lidocaine
When are LAs not that effective?In inflamed tissue (bc acidic tissue → ionize → then not effective)
Normal dose range of Lidocaine & toxic dose range?Normal Dose: 2-5mg/kg
Toxic: 10mg/kg
Normal dose range of Bupivacaine & toxic dose range?Normal Dose: 1-2mg/kg
Toxic: 4mg/kg

Durations + Uses

Question Answer
Reason to use ace & duration?Mild to moderate sedation, duration of 4-6 hours (longest acting premed!)
Reason to use Dex & duration?Moderate to intense sedation & analgesia, duration of 1-1.5hr
Morphine - use & duration?Sedation in dogs, & moderate to intense analgesia. 3-4hr
Buprenorphine - use & duration?Mild to moderate analgesia, 6-8hr
Atropine - use & duration?Antisialagogue (dec salivation), & to inc HR. 30min (to 45min)
Propofol - use & duration?General ANx (induction agent), 10-15min
Alfaxalone - use & duration?General ANx (induction agent), 5-10min
Morphine - use & duration?Moderate to intense analgesia, 3-4hr
Carprofen - use & duration?Mild to moderate analgesia, 24hr
Lidocaine - use & duration?Local analgesia, 1.5-2hr
Bupivacaine use & duration?Local analgesia, 4-6hr
Epinephrine - use & duration?Vasoconstriction, inc myocardial perfusion, inc HR, 2min
Lidocaine - use & duration AS AN EMERGENCY DRUG?Dec AV nodal conduction, 15-20min
Methadone - use & duration?Sedation in dogs & moderate to intense analgesia, duration of 1-1.5hr