dentistry, anesthesia, analgesia

Question 1

in rabbits, which teeth have the worst px when abscessed, and why?

Answer 1

Mandib CT 4&5.
Infections spread beneath the masseter, harder to clean out
Bone debridement is difficult at best - cranial & rostral masseteric fossa is very thin cf. ramus, prone to fx

Question 2

In rabbits, the alveolar bulla of the skull communicates with which CTs?

Answer 2

Apices of maxillary CT 3-6. Abscesses of any of those can lead to retrobulbar abscesses

Question 3

In rabbits, which maxillary CT can be accessed via lateral/extraoral approach?

Answer 3

maxillary CT1 & 2 only. zygomatic arch covers others.

Question 4

how do you access the roots/apices of maxillary CT3-6 (rabbits)?

Answer 4

option 1) through fistula with intraoral approach
option 2) lateral via partial ostectomy of zygomatic arch
option 3) for really huge abscesses, sometimes dorsolateral approach through the orbital fossa

Question 5

why are guinea pig mandib CT hard to deal with?

Answer 5

1) curved so intraoral challenging; 2) the masseter muscles cover the whole side of the face so they are hard to get through to, period.

Question 6

Alpha 2s through SC approach: what to expect

Answer 6

local vasoconstriction, will cause slow or erratic uptake

Question 7

Downside of xylazine in small herbivores

Answer 7

increased sensitivity to catecholamine-induced arrhythmias

Question 8

Ket/med vs ket/midaz (in Healthy rabbits):

Answer 8

Ket/med: Faster intubation, better iso-sparing, less heat loss via esophageal probe. BUT, more laryngospasm with the ket/med.

Question 9

Ket/med vs med/midaz/fent

Answer 9

Ket/med: better qual & length of anesthesia. resp acidosis and dec pA02 devel in both groups. More apnea post intubation in the fentanyl group.

Question 10

Alpha 2s in guinea pigs:

Answer 10

Overall, response is less uniform

Question 11

In chinch, dexmedetomidine/ketamine:

Answer 11

consistent level anesthesia, rapid induction & recovery

BUT longer post-anesthetic anorexia/slower fecal output

Question 12

which patients are most likely to become hypotensive with ketamine, and why?

Answer 12

negative inotrope. Stressy patient will already be as sympathetically maxed as possible, so no way to comp for the neg inotropy, will decrease. Less likely an issue in less stressy patients.

Question 13

In what patients is ketamine contraindicated?

Answer 13

HCM (duh)
Super-stressed (unmasking/low BP)
Possibly if renal compromised. Only an issue in speies that have renal excretion of specific metabolite, norketamine (i.e. cats). Rats, mice and rabbits this is not a prob, they excrete a diff metabolite. Other ECM spp, we don’t know. so as a general rule, don’t use it.

Question 14

What is apneustic ventilation and what drug causes it?

Answer 14

Prolonged pause after inhalation. Ketamine.

Question 15

Ket/alpha 2 combos, esp at higher doses, are more likely to cause what types of issues, compared to ket/midaz?

Answer 15

mild to severe dose-dependent hypotension and bradyarrhythmias

Question 16

telazol contrainidcated in who?

Answer 16

def in rabbits, at >30 mg/kg; in general not used much in rabbits period

Question 17

how long does propofol take to reach peak effect, per pink book?

Answer 17

2 minutes! much longer than we usually assume

Question 18

alfaxan dosing for rabbits?

Answer 18

4 & 6 mg/kg IM were tolerated well, one rabbit died after resp arrest w/ 8 mg/kg IM dose (otherwise healthy rabbits)

Question 19

pink book lists what doses for alfaxan, domitor, torb combo given to rabbits for anesthesia?

Answer 19

Alfaxan 6 mg/kg
Domitor 0.2 mg/kg
Butorphanol 0.3 mg/kg
Anesthesia lasted 1 hour, recovery time lasted 2.5 hours

Question 20

pink book lists what dose for alfaxan alone to a guinea pig?

Answer 20

5 mg/kg IM sole agent produced light sedation for imaging for 30 minutes, no significant cardioresp side effects. 20 mg/kg SC as sole agent gave sedation for 60 minutes.

Question 21

Pink book lists what info about alfaxan for chinchillas?

Answer 21

Alfaxan alone at 5-10 mg SC/IM did not achieve satisfactory sedation. Added torb 0.5 mg/kg, gave rapid short-term anesthesia, inconsistent depth. SIGNIFICANT DROP IN FOOD INTAKE AFTERWARD - NOT RECOMMENDED.

Question 22

Alfaxalone in ferrets per pink book

Answer 22

Sucks big hairy donkey balls. 5-10mg/kg IM alone or with tramadol did not anesthetize them. when inc to 10 and 20 mg/kg IM 2 ferrets died!

Question 23

Rats on alfaxan per the pink book (peritoneal dosing is all that’s listed?)

Answer 23

alfaxan alone was pretty sucky in rats (given IP). at huge doses, and combined with fentanyla nd domitor, able to do surgery. Weird.

Question 24

Etomidate. Fast facts.

Answer 24

IV induction agent, can cause local blood/vein reactions, laryngospasm more likely, less effect on sympathetic nervous system. Inhibits cortisol secretion.

Question 25

Lidocaine CRIs are, obvs, the bomb, but potential downsides?

Answer 25

dec HR & blood pressure - need to monitor those

Question 26

all inhalant anesthetics do what to the heart

Answer 26

Negative inotropes, BP goes down down derry down down

Question 27

sevo may be better than iso how?

Answer 27

surprisingly not really the speed - clinically they end up being similar per pink book. Sevo is less stinky so may be better tolerated for masking.

Question 28

if using an uncuffed tube, do what 3 things for the patient?

Answer 28

clean the oral cavity before intubation, elevate the head, and monitor the oral cavity & tube during the procedure (for any signs of regurge I assume)

Question 29

how long did Nocita last in rats when applied SC?

Answer 29

4 days! Use that shit!

Question 30

if placing an epidural needle using electrical stimulation, what reaction indicates you’re in the right place?

Answer 30

a twitch at 0.3 mA indicates succesful needle placement.

Question 31

If CSF is seen in the needl during an epidural, what dose adjustment?

Answer 31

reduce by 3/4 (should be 1/4 orig dose) to prevent excessive spread

Question 32

what species has a dural sac extending to the sacrum and why does it matter

Answer 32

rabbits, and epidurals can more easily become subdurals

Question 33

TVA for epidurals (if combining drugs etc) should not exceed

Answer 33

0.33 ml/kg. dilute drugs with preservative-free saline only.

Question 34

absence of corneal and palpebral reflexes in small mammals indicates:

Answer 34

too deep, actually! at normal surgical plane the reflexes are still often there (at a low level)

Question 35

in rabbits, oscillometric BPs were fairly consistent with direct BPs when taken where?

Answer 35

Forelimbs, not hindlimbs

Question 36

Rabbit vasoconstrictors/positive inotropes: go!

Answer 36

Dopamine - doesn’t work in rabbits
Phenylephrine - high doses inc BP sl, cardiac input did not go up
Norepinephrine, may be more effective, but doses are high (1-2ug/kg/min healthy, 5-7 ug/kg/min septic)

Question 37

tramadol: who does it work in?

Answer 37

Varies heavily. Rats and rabbits both make the active metabolite. rat studies show it works, though more complicated with chronic pain. Chinchillas it def does not work.

Question 38

Tapentadol: wtf is it?

Answer 38

sort of like tramadol but may work better? new drug, little info. Rabbit study showed it worked very well, same with rats and mice.