Anes- Small animal Anesthesia 1

untimely's version from 2015-05-12 02:29

Routine patients intro

Question Answer
CQ: dog spay, everything WNL but Co2 high, what do?manual ventilation! give O2 only if you're not giving enough FGF and theyre rebreathing
CQ: if CO2 is 7%. how do you calc mmhg? (5% normal)760mmhg(atmospheric) divided by / x = 7%. x= 50 (above 45)
ASA for a routine pt?1 or 2
the longer the anesthetic procedure, the higher the risk for...infections/complications
Patient physical status of ASA 1?Healthy Patient (no medical indication for a procedure) aka ELECTIVE procedure
Patient physical status of ASA 2?Mild systemic disease (ex: compensated mitral valve insufficiency)
Patient physical status of ASA 3?Severe systemic disease
Patient physical status of ASA 4?Severe systemic disease which is a constant threat to life
Patient physical status of ASA 5?Moribund pt, not expected to survive the next 24hr (with or without intervention)
Is it a routine pt? consider breed: dobermantest for mucosal bleeding time. if not vWB, then fine
Is it a routine pt? Consider Breed: bulldognot a routine pt. bc brachycephalic.
Is it a routine pt? Consider Breed: boxerNo acepromazine. will sleep for the next 5 days.
Is it a routine pt? Consider Breed: afghan/other sighthoundthiopental contraindicated. And careful with long acting drugs, they will work REALLY long. and keep them warm.

Routine patients DRUGS

Question Answer
which premeds have the most CV effects?A-2s
longest acting sedative drug?ACE (and god forbid it's in a boxer, then it is for forever)
how do you admin ACE?IM preferred, but IV can be used
commonly used Sedatives in SA anesthesia (3 groups)(1) Phenothiazines (acepromazine) (2) α2-Agonists (e.g. dexmedetomidine) (3) Benzodiazepines (diazepam, midazolam, zolazepam)
Injectable Anaesthetics commonly used in SA anesthesia? (5)Propofol, Thiopental, Ketamine, Alfaxalone, Etomidate
Opioids commonly used in SA anesthesia? (5)(there are more tho) morphine, fentanyl, buprenorphine, hydromorphone, butorphanol
Inhalant anaesthetics commonly used in SA anesthesia?Isoflurane, sevoflurane
what kinda drug is Acepromazine?sedative, antianxiety, antiemetic
does Acepromazine provide analgesia?NO
what's your big blood pressure dropper?ACE
how does acepromazine affect the CV system (incld heart and blood)****DEC BLOOD PRESSURE***(alpha 1 antagonism- (alpha on outside of vessel beta on inside) ), antiarrythmic (and minimal effects on heart), also Inhibits platelet aggregation (inc bleeding tendency). Also causes sequestration of erythrocytes in the spleen (prolly bc dilation). Because of the vasodilation it causes, there is also a loss of thermoregulation
how would you adjust dose of acepromazine based on animal's size?BIGGER animal needs SMALLER dose. LEAN dogs also need a smaller dose. (so fatass Rollie needs less food AND less ace--> because he's an ace at being fat)
which type of patient should you AVOID giving ace to?BOXERS!!! (or use lowest dose possible) very sensitive to ace
you should try not to stress a dog or give it ___ when you sedate with ace--- why?stress or give epinepherine. Bc Ace blocks alpha-1 (sympathetic) the adrenaline will bind to Beta-2 instead--> MORE vasodilation (and the ace is already vasodilating)
DONT use ace of a pt has these conditions..shock/hypovolemia (bc of vasodilation), anemia (sequestration), hemorrhage/coag disorders (platelet inhibition), CNS disorders (might cause seizures), liver dz, cachexic animals, animals <3mo, boxers
what's one benifit alpha-2 agonists have over ace?you can ANTAGONIZE THEM (Atipamezol)
what is the antagonist for alpha-2s?Atipamezol
which is anti-emetic?ace
which sedative provides analgesia?Alpha-2s
do alpha-2s provide analgesia?YES
Alpha-2s are only to be used in ___ dogsHEALTHY
how do alpha-2s affect the CV system?Bradyarrhytmias (sig sinus bradycardia), AV Blocks, initial increase in blood pressure, thereafter decrease to normal or low values
what are the 3 alpha-2s we use in SA anesthesia?Medetomidine, Dexmedetomidine, Xylazine
how can you admin Alpha-2s?IV or IM
which A-2 causes the most vomiting?xylazine- (risk of aspiration by relaxation of larynx and suppressed coughing reflex) (also less potent, so usually deto/medeto preferred in sm ani))
potent visceral analgesiamedetomidine (could be any of the A-2s but was mentioned under here specifically)
what should you know about the sedation provided by alpha-2s?sometimes not reliable sedation in very excited animals, sedation not always reliable, animals may suddenly wake up or bite
which types of patients do you NOT want to use alpha-2s in?cardiac pts (can cause bradyarrythmias/av blocks), shock/bad condition animals, animals that cant vomit like GVD, not fasted, very young or very old
which type of sedative should you only use in healthy, non-excited adult (not young or old) animals?alpha2s
which group of sedatives are actually poor sedatives?benzos-- not reliable sedatives! so-­‐called paradoxical excitement when administered to adult, healthy animals
which sedatives are really only useful in the very young, very old, or very sick?benzos (ben is only nice to you if you're sick or helpless)
When are benzos usually used?They may be used in combination with opioids and with injectable anaesthetic drugs for induction of anaesthesia. (in class she said usually used for good mm relaxation)
do benzos provide analgesia?no
which sedative has minimum CV effects?benzos
what are the three benzos we usually use?Diazepam, Midazolam, Zolazepam
what can you NOT GIVE IM?diazepam
how can you admin benzos?DIAZEPAM IS NOT IM. can give IV. Otherwise benzos can be IM, IV, PO, rectally
convulsant vs anticonvulsant drugsBENZO=ANTICONVULSANT (diazepam). CONVULSANT= ace (possibly)
(long notes) appetite stim in cats?diazepam (benzo)
Antagonist for benzos?Flumazenil (ben can make me feel better when i have the flu)
when do you use zolazepam? (benzo)only with tiletamine as a combo (telazol)
for painful animals, what kinda opioids are used?pure mu agonists
how do opioids affect sedatives and anaesthetic drugS?synergictic-- allow you to reduce doses on sedatives and anesthetic drugs
how does butorphanol affect the opioid receptors?agonistic and antagonistic activity
what are two possible uses for butorphanol?analgesic/antitussive
why might you want to give butorphanol after already having given a different opioid?because butorphanol has agonist and antagonist activity, you can give it to antagonize the effect of a pure-mu opioid without completely abolishing all analgesic affect
antagonist for opioids?naloxone
what are two disadvantages of butorphanol?insufficient analgesia for severe/somatic pain (is an agonist and antagonist), and mild CNS stim in healthy animals possible
ideal combo: butorphanol and _________midazolam
how does Buprenorphine affect the opioid receptors?partial mu agonist
transmucosal opioid?buprenorphine
how are the pure mu agonists different from the partial agonists and agonist-antagonists?more severe resp depression, more GI and CNS effects (sedation/euphoria). However, with these, inc the dose can inc the effect
meperidine is a what and is akapure mu agonist, aka pethidin
what are the pure mu agonists?morphine, meperidine, methadone, fentanyl, Hydromorphone/Oxymorphone
which opioid is the transdermal patch one?fentanyl
recommended fasting time? who don't you fast?8-12hr, not for pediatric pts
if you are going to use an emergency chart for drugs, what must you keep in mind?MAKE SURE conc on chart matches dose on bottle
which sedative tends to be a strong emetic?xylazine


Question Answer
chronological process during performance of general anesthesia?premed--> wait till premed sedates them--> IV catheter--> IV induction of anesthesia--> ET intubation (optional if injectiable anesthesia)--> connect to anesthesia machine (if injectable, re-inject manually or do CRI)--> simultaneous infusion of analgesics, mm relaxants, and/or sedatives (balanced anesthesia)
6 most commonly used induction agents in dogs?thiopental, propofol, ketamine/diazepam, Alfaxalone, Etomidate
(from injectables lecture) thiopental stuff you should knowsuper short acting. precipitates in LRS, accumulation, works on GABA (barbiturate), can cause bigeminy(arrythmias), tissue necrosis if extravasion (so use IV cath)
(from injectables lecture) CONTRAINDICATIONS of thiopental?hepatic dz, sighthounds
how can you reduce the amount of thiopental used? give a part of the dose, then stop and give some diazepam or midazolam, before giving more thio until effect--> reduces S/E (arrythmia) (*avoid repeated injections bc accumulation of thio) (my thighs accumulate too)
how should you admin propofol, and what should you always have on hand if using propfol?inject SLOWLY (risk of apnea) titrate to effect. always have ET tube on hand!! (in case of apnea)
(from injectables lecture) whats PropoFlo 28 and what should you know?alternative formulation of propofol without the egg and soy in it, but ONLY FOR DOGS
(from injectables lecture) propofol+ cats- what to know?PROLONGED RECOVERIES (no glucoronidation), possible heinz body anemia
(from injectables lecture) common adverse affects of propofol?HYPOTENSION, RESP DEPRESSION
(from injectables lecture) contraindications for propofolavoid repeated admin in cats
*when is Etomidate most useful for induction? (in who, in what protocol?)if SICK/DEBILITATED/UNSTABLE, can give, in order, for induction: fentanyl-->diazepam-->etomidate
(from injectables lecture) etomidate is the ideal induction agent in...compromised pts/high risk
(from injectables lecture) what are some cons of etomidate?inhibits adrenal steroid production
what is important to know about how to use Alfaxalone?always use premed and admin slow
(from injectables lecture) alfaxalone is good for what kinda admin, and how is it affected by plasma proteins?suitable for CRI and no sig protein binding (so hypoalbu animals fine)
what do you usually combine ketamine with for induction? any substitutes?usually diazepam (ONLY IV FOR DIAZEPAM), can replace with midazolam but STILL NO IM, unpredictable rxn
(from injectables lecture) what are ketamines CV effects?increase in HR, BP and CO--> but ALSO direct myocardial depression
(from injectables lecture) cons to ketamine?sensitivity to noise, light, and handling, hyperexcitability, crosses placenta. can NEVER use alone, mm rididity
(from injectables lecture) pros of ketamine?analgesia, symp. stim, bronchodilation
(from injectables lecture) contraindications of ketamine?no CV dz, no head trauma, no cesarean