Anesthesia - Small Animal ANx 1

drraythe's version from 2016-03-15 20:29

Routine PTx intro

Question Answer
***Dog spay, everything WNL but Co2 ↑, what do?Manual ventilation! Give O2 only if you're not giving enough FGF & theyre rebreathing
***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 PTx?1 or 2
The longer the anesthetic procedure, the ↑er the risk for...Infxns/complications
PTx physical status of ASA 1?Healthy PTx (no medical indication for a procedure) aka ELECTIVE procedure
PTx physical status of ASA 2?Mild systemic dz (ex: compensated mitral valve insufficiency)
PTx physical status of ASA 3?Severe systemic dz
PTx physical status of ASA 4?Severe systemic dz which is a constant threat to life
PTx physical status of ASA 5?Moribund PTx, not expected to survive the next 24hr (w/ or w/o intervention)
Is it a routine PTx? Consider breed: Dobermantest for mucosal bleeding time. If not vWB, then fine
Is it a routine PTx? Consider Breed: Bulldognot a routine PTx. bc brachycephalic.
Is it a routine PTx? Consider Breed: BoxerNo Acepromazine. Will sleep for the next 5 days.
Is it a routine PTx? Consider Breed: Afghan/other SighthoundThiopental contraindicated & careful w/ long acting drugs, they will work REALLY long & keep them warm

Routine PTx DRUGS

Question Answer
Which premeds have the most CV effects?A-2s
Longest Acting sedative drug?ACE (& 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 Anesthetics commonly used in SA anesthesia? (5)Propofol
Opioids commonly used in SA anesthesia? (5)(There are more tho)
Inhalant anesthetics commonly used in SA anesthesia?Isoflurane
What kinda drug is Acepromazine?Sedative
Does Acepromazine provide analgesia?NO
What’s your big blood pressure dropper?ACE
How does Acepromazine affect the CV system (incld heart & blood)****↓ BLOOD PRESSURE***(α -1 antagonism (α on outside of vessel β on inside) )
Antiarrhythmic (& minimal effects on heart)
Also Inhibits platelet aggregation (↑ bleeding tendency)
Also czs sequestration of erythrocytes in the spleen (prolly bc dilation). Bc of the vasodilation it czs, 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 & less ace → bc he's an ace at being fat)
Which type of PTx 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 w/ ace-why?Stress or give epinephrine. Bc Ace blocks α-1 (sympathetic) the adrenaline will bind to Beta-2 instead → MORE vasodilation (& the ace is already vasodilating)
DONT use ace of a PTx has these conditions...Shock/hypovolemia (bc of vasodilation), anemia (sequestration), hemorrhage/coag disorders (platelet inhibition), CNS disorders (might cz seizures), liver dz, cachexic animals, animals <3mo, boxers
What’s 1 benefit α-2 agonists have over ace?You can ANTAGONIZE THEM (Atipamezol)
What is the antagonist for α-2s?Atipamezol
Which is anti-emetic?Ace
Which sedative provides analgesia?α-2s
Do α-2s provide analgesia?YES
α-2s are only to be used in ___ dogsHEALTHY
How do α-2s affect the CV system?Bradyarrhytmias (sig sinus bradycardia)
AV Blocks - Initial ↑ in blood pressure, thereafter ↓ to normal or↓values
What are the 3 α-2s we use in SA anesthesia?Medetomidine
How can you admin α-2s?IV or IM
Which A-2 czs the most vomiting?Xylazine - (risk of aspiration by relaxation of larynx & 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 α-2s?Sometimes not reliable sedation in very excited animals, sedation not always reliable, animals may suddenly wake up or bite
Which types of PTx do you NOT want to use α-2s in?Cardiac PTxs (can cz bradyarrythmias/av blocks) Shock/bad condition animals
Animals that can’t 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?α-2s
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 w/ opioids & w/ injectable anesthetic drugs for induction of anesthesia. (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 3 Benzos we usually use?Diazepam
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 w/ Tiletamine as a combo (Telazol)
For painful animals, what kinda opioids are used?Pure mu agonists
How do opioids affect sedatives & anesthetic drugs?Synergistic - Allow you to reduce doses on sedatives & anesthetic drugs
How does Butorphanol affect the opioid receptors?Agonistic & antagonistic activity
What are 2 possible uses for Butorphanol?Analgesic/antitussive
Why might you want to give Butorphanol after already having given a different opioid?Bc Butorphanol has agonist & antagonist activity, you can give it to antagonize the effect of a pure-mu opioid w/o completely abolishing all analgesic affect
Antagonist for opioids?Naloxone
What are 2 disadvantages of Butorphanol?Insufficient analgesia for severe/somatic pain (is an agonist & antagonist) & mild CNS stim in healthy animals possible
Ideal combo: Butorphanol & _________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 & agonist-antagonists?More severe resp depression, more GI & CNS effects (sedation/euphoria). However, w/ these, ↑ the dose can ↑ the effect
Meperidine is a what & is akaPure mu agonist, aka pethidine
What are the pure mu agonists?Morphine
Which opioid is the transdermal patch one?Fentanyl
Recommended fasting time? Who don't you fast?8-12hr, not for pediatric PTxs
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 injectable 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
(From injectables lecture) Thiopental stuff you should knowSuper short Acting. Precipitates in LRS, accumulation, works on GABA (Barbiturate), can cz bigeminy (arrhythmias), tissue necrosis if extravasation (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 & give some Diazepam or Midazolam, before giving more thio until effect → reduces S/E (arrhythmia) (*avoid repeated injxns bc accumulation of thio) (my thighs accumulate too)
How should you admin Propofol & 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 & what should you know?Alternative formulation of Propofol w/o the egg & soy in it, but ONLY FOR DOGS
(From injectables lecture) Propofol+ cats-what to know?PROLONGED RECOVERIES (no glucuronidation), possible Heinz body anemia
(From injectables lecture) Common adverse effects 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 PTxs/↑ 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 & admin slow
(From injectables lecture) Alfaxalone is good for what kinda admin & how is it affected by plasma proteins?Suitable for CRI & no sig protein binding (so hypoalbu animals fine)
What do you usually combine Ketamine w/ for induction? Any substitutes?Usually Diazepam (ONLY IV FOR DIAZEPAM), can replace w/ Midazolam but STILL NO IM, unpredictable rxn
(From injectables lecture) What are Ketamine’s CV effects?***↑ in HR*** BP & CO → but ALSO direct myocardial depression
(From injectables lecture) Cons to Ketamine?Sensitivity to noise, light & handling
Crosses placenta
Can NEVER use alone, mm rigidity
(From injectables lecture) Pros of Ketamine?Analgesia
Symp. Stim
(From injectables lecture) Contraindications of Ketamine?No CV dz
No head trauma PTx
No cesarean PTx