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Anesthesiology - Quiz 1-1

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pufexaxe's version from 2016-09-19 03:08

Intro + Planning

Question Answer
Definition of Sedation/Tranquilization? What are the 1° intentions of this(2)?CNS depression in which the PTx is awake but calm
The 1° intentions are:
(1) Sedation is recommended to allow PTx the ability to tolerate unpleasant diagnostic or surgical procedures & to relieve anxiety & discomfort
(2) For uncooperative PTxs, it can help expedite & simplify special procedures that require little or no movement.
Define General AnesthesiaDrug induced & reversible state of:
Loss of consciousness
Loss of sensation (analgesia)
Mm relaxation (immobility)
Hyporeflexia
What does a "classic anesthetic drug" do?Leads to unconsciousness
Immobility
Analgesia
Reduced reflexes
(LIAR)
What is "balanced anesthesia"?Surgical anesthesia produced by 2 or more drugs or anesthetic techniques
Define HypnosisArtificially induced sleep, from which the PTx can be aroused by sufficient stimulation (this is not the case w/ general anesthesia)
What is Neuroleptanalgesia?Hypnosis + analgesia produced by the combination of a neuroleptic drug (eg: Acepromazine) & an analgesic drug
What are the 6 main types of premedications used?Phenothiazines (Acepromazine)
α-2 Agonists (Xylazine, Detomidine, Medetomidine, Dexmedetomadine, Romifidine)
Benzodiazepines (Diazepam, Medazolam)
Opioids
Anticholinergics (Atropine, Etomidate)
Dissociatives (Ketamine, Tiletamine)
When do most deaths from anesthesia occur? Why?48 hrs POST OPERATIVELY! Bc they are put in a cage while recovering & are not checked on
What is Anamnesis?The pre-anesthetic assessment.
It inclds:
Hx
PE
Blood/other tests
Concurrent drugs
Previous anesthetic records
Etc
What are some reasons PU/PD warrants further investigationMight indicate:
Renal dz
Diabetes
Pyometra
If a dog has a harsh cough, often at night, what might it indicate?Cardiac problems
Concurrent medications w/ potential drug interactions → Corticosteroids. What problems might this type of drug cz?Chronic Tx will depress adrenal fxn. Might compromise renal fxn & predispose to GI ulceration in combination w/ NSAIDs
Concurrent medications w/ potential drug interactions → NSAIDs. What problems might this type of drug cz?Highly protein bound → may alter pharmacokinetics of other protein bound anesthetics (NOT ACTUALLY A CLINICAL PROB THO)
Concurrent medications w/ potential drug interactions → ABx. What problems might this type of drug cz?Aminoglycosides potentiate NMB (neuromuscular blockade) & renal tox
Concurrent medications w/ potential drug interactions → Cardiac Glycosides. What problems might this type of drug cz?Dysrhythmias & reduced CO (Cardiac Output)
Concurrent medications w/ potential drug interactions → Anticonvulsants. What problems might this type of drug cz?May reduce induction dose of anesthetic
Concurrent medications w/ potential drug interactions → Antidepressants. What problems might this type of drug cz?May interfere w/ neuroactive drugs
4 reasons youd see a pale mucous membrane?Hypotension
Hypothermia
Hypertension due to vasoconstriction (a-2 agonists)
Anemia
What does a brick red mucous membrane w/ a CRT of >2sec indicate?Hypercarbia (elevated CO2)
Endotoxemia
Vasodilation
(bricks are HEVey)
Which hemoparasites are we especially looking for in Grenada? Which lab Parameters might give us indications of a problem w/ this?Ehrlichia
Heartworm
Anaplasma
(look at PCV, TP & platelet count)
** ASA status 1 - What does this mean?EXCELLENT - Normal healthy PTx. elective sx: spay/neuter elective knee sx
** ASA status 2 - What does this mean?GOOD - MILD SYSTEMC DZ. Slight to moderate dz (uncomplicated fracture, compensated cardiac dz, slight dehydration)
** ASA status 3 - What does this mean?FAIR - SEVERE SYSTEMIC DZ. Moderate to major dz, not incapacitating. (chronic heart dz, chronic anemia, trauma)
** ASA status 4 - What does this mean?POOR - SEVERE SYSTEMIC DZ WHICH IS A CONSTANT THREAT TO LIFE (like GDV). Severe, life-threatening, systemic dz (toxemia, uremia, heart failure, severe anemia, severe hypovolemia)
** ASA status 5 - What does this mean?CRITICAL - Morbund or dying
What are 4 good reasons youd want pre-anesthetic fasting?(1) Less likely regurgitation/aspiration
(2) Reduced pressure on the diaphragm
(3) Reduced intraabdominal pressure → venous return less impaired → CO better maintained!!
(4) Reduced risk of tympany
What is the minimum time of preanesthetic fasting for dogs/cats/horses when gastic emptying is normal?4-6 hrs
What benefit might starvation/fasting have on ruminants in particular in regards to a specific type of dz they get?Bloating & tympanies are reduced!
What are the recommended fasting times for a...monogastric? Equine? Cattle? Camelid?MONO: 8-10 hr
EQUI: 6-12 hr
CAMELID: 12-18 hr
CATTLE: 12-24 hr (**additional water deprivation for 8-12 hr helps prevent bloat & tympany)
If there is an emergency & you cannot fast, what can you do to prevent regurg/aspiration?Rapid ET intubation w/ a SEALED TUBE!
What is the major caveat to fasting before a procedure?Neonates, very young animals & small rodents should NOT be starved (or for only very short periods)
Which animal has the highest anesthetic risk?Horses (of courses)
When do most deaths occur due to anesthesia?W/in THE 1st 48 HRS POST-OP!!!
What are 2 things that can ↓ the anesthetic risks in horses?Premed w/ Acepromazine & use TIVA (Total IntraVenous Anesthesia)
What are some things which will ↑ the anesthetic risks in horses?Type of Sx (i.e.: orthopedics)
Duration of anesthesia
Time of anesthesia (night & weekend R bad)
No premed (use Ace!)
Gaseous induction & maintenance (use TIVA if possible)
What can ↓ anesthetic risks in cats?Using a pulse oximeter
What are some things which will ↑ the anesthetic risk in cats?ASA 3-5
Major procedure
Weight <2kg or >6kg
Age >12y
ET intubation (laryngeal spasms w/ fragile tissue)
IV fluids (overinfusion specifically)
What are some things which will ↑ the anestheric risk in dogs?ASA 3-5
Major procedure
Urgent ANx
Duration of procedure
Weight <5kg
Age >=12yr
Injectable or inhalant alone (as opposed to balanced anesthesia)
What are the benefits to placing an IV catheter in the PTx? (5)(1) Stress free anesthesia induction
(2) No risk of perivascular injxn
(3) Admin of IV fluids
(4) Rapid access in case of complications
(5) Avoidance of intra-arterial injxn
Yellow catheter is what size?24G - tiniest
Blue catheter is what size?22G - small
Pink catheter is what size?20G - medium. MOST COMMONLY USED IN SM AN, so said she
Green catheter is what size?18G - biggest
memorize

Premedication: Intro, Phenothiazines & Butyrophenones

Question Answer
What does the peri-anesthetic process incld?Preparation
Premed
Anesthesia induction
Maintenance
Recovery
Immediate post-operative period
Route & timing of premed → (in general) IM/SC - how long does it take for induction? Who do you use this in?15-45min before induction. Use in small animals.
Route & timing of premed → (in general) IV - how long does it take for induction? Who do you use this in?(1) 5-10 min for induction in horses or ruminants
(2) Rapid sequence induction in small animals
Route & timing of premed → (in general) PO - how long does it take for induction? Who do you use this in?60min before induction (rare, species limitations)
Which drug is in the "Phenothiazines" category?ACEPROMAZINE
(also Chlorpromazine, Propionylpromazine & Promazine, but we don't seem to care about these too much...)
What is the mechanism of action for Acepromazine? (What effect does the MOA result in?)***2 MOAs!***(what an ace!)
(1) Blocks (antagonist) D2 receptors (antipsychotic, sedative, anti-emetic effect)
(2) Blocks (antagonist) α-1 adrenoreceptors (vasodilation, hypotension)
(***do not confuse the α-1 antagonism here for the α-2 AGONIST of Xylazine etc)
((3) Also blocks H1 acting as an anti-histaminergic)
What are the routes of admin by which you can give Acepromazine?(1) IV, IM, SC
(2) PO
What is the IV onset of Acepromazine? How about IM/SC?(1) IV - up to 20 minutes for onset of action
(2) IM/SC - up to 45 minutes
Who can you give Acepromazine orally to & in what forms?Tablets for dogs, pastes for horses
How long does the peak effect of Acepromazine last? How long is the duration?Peak effect up to 40 min, but there is a LONG DURATION of 4-6 hours (why you can take them on planes)
How is Acepromazine metabolized?Hepatic metabolism & slow clearance
Central effects → What is sedation like? How does it affect your anesthetic dose when used as a premed? How does it affect motor activity? How does it affect the GI? What interesting tidbit is there about Ace & CNS?Ace provides variable sedation
Allows you to ↓ your anesthetic dose
↓ motor activity
Works as an ANTIEMETIC! (keep pets from getting airsick → think about how Dopamine plays a role in emesis & we are antagonizing D2 receptors)
Ace can reduce the seizure threshold & is contraindicated in seizure PTx (seizure on a plane would be scary)
Central effects → Does Acepromazine provide analgesia?NO!!! However, it can potentiate analgesics
CV effects → How does Acepromazine affect blood vessels? Heart rate?Czs VASODILATION bc of Ace's α-1 blocking. However, this czs hypotension so dont use in shock or dehydration PTxs! However, the HR stays the same or only ↑ slightly (you might have hypotension but heart doesnt seem to compensate, which is why it might be worrisome on planes)
CV effects → How does Acepromazine affect the PCV (& why)?It leads to a ↓ in the PCV bc it czs erythrocytes to be sequestered in the spleen
CV effects → Explain the relation btwn Acepromazine & arrhythmias?Acepromazine can stabilize the heart against catecholamine-induced arrhythmia (anti-arrhythmic) (bc of α-1 block)
CV effects → Explain the "Epinephrine reversal" side effect of AcepromazineIf you administer Acepromazine & then you administer Epinephrine, you will see paradoxical vasodilation & hypotension (usually Epi would cz vasoconstriction! However, bc since the α-1s are blocked by Phenothiazines, Epi cannot be effective on those receptors (where it would cz vasoconstriction) & so it moves to the B-2 receptors where it czs MORE vasodilation → double vasodilation)
CV effects → Species to be cautious about w/ Acepromazine?Occasional bradycardia/collapse in boxers (Berry the Boxer thot she was an ace until her heart slowed down too much)
Explain why you might want to give a blanket to a dog on AcepromazineAce can cz poikilothermia, which is a loss of normal thermoregulation. So putting them in a place too cold or too hot can be a problem. (Why they cuddle on the plane....to stay warm)
How does Acepromazine affect respiration?Minimal effects on respiration
Thing you should note about horses & Acepromazine?Can cz PRIAPISM (persistant & painful erection) in horses, which is a big problem if it is a breeding stallion
Can Acepromazine cz allergies?Actually, it works as a anti-histaminergic (an Ace at carrying the Benadryl to me)
What is the risk of clotting w/ use of Acepromazine?TRICK QUESTION - It actually INHIBITS platelet aggregation (which is great since when the blood slows down from the vasodilation you arent going to throw a clot)
Which sedative can you use if you want them to be sedated, but if you rouse them they can walk to the induction table w/ you?Acepromazine
In which animals can you use Acepromazine as a premedication?Small animals & horses (ace wrap on horse...obv in sm Anx)
Can you combine Acepromazine w/ opioids?YES! it doesnt provide analgesia & it can help potentiate them so you can use less. Yay!
A specific situation where use of Acepromazine to sedate a horse is ESPECIALLY useful?Sedation where ataxia should be avoided (such as during transport)
How would you administer Acepromazine if you wanted long-term sedation effects?PO
WHAT ARE THE CONTRAINDICATIONS OF ACEPROMAZINE? (6)Boxers (relative, can cz bradycardia & collapse (most likely due to vasovagal syncope) )
Breeding stallions (due to priapism)
Animals w/ hypotension, shock (due to α-1 block causing vasodilation)
Anemia & bleeding disorders (↓ PCV due to splenic sequestration)
Which drugs are in the Butyrophenones category?Azaperone (GREAT FOR PIGS) & Droperidol (Innovar-Vet) (These drugs act really similarly to the Phenothiazines so she considers them together w/ Ace)
What is the clinical use of AZAPERONE? (2) (What group does it belong to again?)(1) Mainly used in combination w/ Ketamine for anesthesia
(2) **Sedation of PIGS w/ IM admin (AZAz the PIG-ZAZ) (belongs to the Butyrophenones group)
memorize