Final - Oral/GI, Hepatic/Renal, Feline, Geriatric, Resp Disease

How long do we fast dogs before surgery

4-6hrs (shorter for small, young, and diabetic) longer for dogs with known risk of regurg

When do you withold water before surgery?

only if known hx of risk of regurg

What are other reasons to fast LA besides risk of regurg?

decreases weight of rumen, decreases risk of colic

How long do you fast calves/small ruminants?

food - 12-24, water - 8-12

How long should you fast adult ruminants?

food - 24-48, water - 12-24

Young ruminatns nursing are not fasted due to ___

hypoglycemia

How long do you fast horses?

6-12hrs (fast only grain, can have water and hay right before)

What drugs do you AVOID with a risk of regurg?

opioids, a2 agonist

What drugs can help prevent regurg?

antinausea: famotidine, omeprazole, maropitant prokinetics: metoclopramide, lidocaine, cisapride

What are concerns for dentals?

geriatric, pain, consistent depth, airway protection due to the use of lots of fluids during dentals

What is a concner with forcing the mouth open during dentals?

occlude maxillary artery → blindness

What are some concernsa with exploratory laparotomies?

pressure on cdVC, vagal stimulation (low HR)

Why might you give lidocaine before an exploratory lap?

stabilize arrhythmias

When is there a risk of release of toxins in an exploraotry lap?

de-rotation or abcess

Why do you avoid using etomidate in SA with sepsis or extreme illness?

suppresses adreniline from the adrenal glands for 24 hrs

What are some challenges from a colic surgery?

severe hypotension → ventilatory issues

define monro-kellie doctrine

the sum of brain fluid, CSF, and blood always stays the same

What is the cushings reflex?

bradycardia, hypertension, and dim resp effort = ICP

How do you treat ICP?

elevate head 30, hyperventilation, mannitol/hypertonic saline, ± steroids

Why does hyperventilation help ICP?

causes vasoconstriction in brain, decreases perfusion (but time limited response)

What drugs do you avoid with ICP?

ketamine, ace

intrinsic bloodflow control to the liver is only applicable to which vessel?

hepatic artery

describe HABR (hepatic artery buffer response)

portal vein blood decreaes → adenosine concentraiton increaess → arterial vasodilation and increased blood to the live

autoregulation of blood flow to the liver is present as long as what?

MAP remains above 60

What extrinsic factors is the hepatic artery susceptible to?

a/b adrenergic, dopamine

What extrinsic factors is the portal vein susceptible to?

a adrenergic, dopamine

If intestinal blood flow increases, hepatic blood flow ____

increases, another extrinisc regulation

What are some extrinsic factors (besides blood-borne factors) that regulated hepatic bloodlfow?

intestines, ventilation, CO2

does hypocapnia result in increased or decreased heaptic bloodflow?

decreased. low CO2 → less blood to the liver

What are measurments of hepatic FUNCTION

BUN, Glu, TP(alb), ammonia, bile acids, coag factors

Why do we not use Phenothiazine (ace) in a hepaticlaly compromised patient?

1) systemic vasodilation → decreaesd blood to liver 2) highly protein bound → if liver isn’t making as many proteins will have a prolonged effect 3) platelet aggregation 4) no reversal

T/F a2 agonists should not be used in a hepatic patient

false. there is a reversal (atipamezole)

T/F a2 agonists affect liver blood flow and decrease hepatic enzymes

do NOT affect blood flow but DO decrease enzymes.

T/F you can use benzos in a hepatic patient

true, with HE being the exception

What is the reversal for benzo?

flumazenil

What benzo is important when giving to cats?

diazepam → must be given OP

What is the concern with opioids in hepatic patients?

will last longer bc hepatically metabolized → except for Remifentanil

Which inhalant should be avoided with liver issues?

halothane

T/F all inhalatns cause decreased hepatic blood flow and impairment of HABR

true

What controls the intrinsic autoregulation of renal bloodflow?

MAP

What are some extrinsic factors that control renal blood flow?

catecholamines, RAAS, prostaglandins

prostaglandins cause ___ in the kidnesy

dilation

describe the RAAS system

low RBF → juxtaglomerular cells → renin → angiotensin 1 from the liver → angiotensin II from the lungs → constriction, aldosterone forom adrenals,

What are the most important parameters to monitor in a renal patient?

hydration, blood volume, T

T/F msost anesthetics cause decreased RBF and GFR

true

Why do we not use Phenothiazine (ace) in renal patients?

causes hypotension→ lowers blood flow, dopamine receptor antagonist, so hinders RBF, no antagonists

What are the contradictory effects a2 agonists have on kidneys?

decreased RBF, but may also be renal protective → cause diuresis by decreased factors that save fluid

Although benzos dont have a major effect on RBF, what is the best benzo for renal patinets?

midazolam, has lower chance of causing renal tubular injury

Can you use opioids in renal patients?

yes, but maybe avoid morphine or meperidine bc these are cleared by kidney

What is the only injectable anesthetic that has a negative impact on kidneys

ketamine

Why is ketamine harmful to the kidneys?

its active metabolite (norketamine) is excrete via kidneys

What should be the cats HR under andesthesia?

140-200

How do you use doppler to get a BP on a CAT?

doppler systolic reading + 14

Why is reading a cats ECG hard?

rapid HR, artifacts, small electrical pulses

Why is entubating a cat difficult?

smaller than dogs, edema or laryngospasm may occur

How do you blunt laryngospasms?

lidocaine 2%

Why do cats have a slower clearance of propofol?

they are deficient in glucuronidation, whihc is a form of propofol elimination

What are the dangers of repeated doses of propofol in cats?

RBC oxidative injury and Heinz body formation

What are the dangers of giving etomidate and diazepam to cats?

What organ is ketamine harsh to?

kidney

opioids cause ____ in cats

behavioral changes (euphoria, purring, rubbing) and mydriasis

What specific effect does hydropmorphone have on cats?

hyperthermia

Why do cats have a risk of spinal infection with an apidural?

their spinal cord extends beyond L7

How long do you wait to intubate after applying lidocaine to the layrynx in a cat?

45s

Are the inhalant anesthetic requirements for cats higher or lower than dogs?

higher MAC values

What blocks shoul dbe performed in the cat to avoid globe puncture during a dental?

infraorbital and maxillary blocks

What are the cardiac changes experienced by geriatric patients?

arrhythmias, reduced CO, increased vagal tone (low HR)

What are the pulmonary changes found in geriatric patients?

atrophied intercostal muscles, decreased fxn reserve

What does the geriatric’s poor liver fxn mean for anesthesia?

drugs will tak elonger to leave the system

What is a key part of the hx for a geriatric that might tell you about their ability to handle anesthesia?

exercise intolerance

What does a geriatric patient’s pre workup look like before anesthesia?

ECG, chest rads/echo maybe, stabilization, catheter always, preoxygenation, and fluids

What is the purpose of preoxygenation?

increase O2 in the lungs to replace the nitrogen from the air

reduce doses of drugs in geriatrics to ___%

5o%

Why is acepromazine not a good premed choice for geriatrics?

it causes hypotension, there is no analgesic effect, and there is no reversible

What are the considerations when giving benzodiazepines as a premed to geriatrics?

1) good - very little cardiac depression and Flumazenil as reversible 2) bad - no analgesia and lasts a long time END - good as adjuct What is te

What is the main contraindication for benzodiazepiens?

excited patients

What are the pros and cons of a2 agonists as premed for geriatrics?

pro: reversible, m relaxant 2) initial constriction w bradycardia then dilation with hypotension, vomititngI

Is it ok to give dexdomitor to geriatric patients?

in micro doses, for dysphoria

What are the pros and cons of opioids as a premed to geriatrics?

pro: good for severe pain, reversible is Naloxone, minimal cardiac depression con: represses resp, bradycardia, nausea

Why do you not prefer to use NSAIDS in premed to geriatrics?

cause renal and liver stress, (hypotension and dehydration)

You have started to induct a geriatric patient and they start seizing. What do you do and what is this fron?

wait a few minutes for it to pass, from the propofil

What are the cons of etomidate?

gagging and twittching, adrenal suppression for 24 hrs, hemolysisWhy

Why do we prefer to not use etomidate in really sick patients?

can cause adrenal suppression for 24 hrs

What drug is alfaxan used for?

induction

What is the main con with ketamine?

sympathetic stimulation (increases HR), can even caues ICP therefore directly depresses the heart

How is ketamine excretex in cats?

kidney

What is old dog lung?

have to keep changing the induction gases to help maintian the plane of anesthesia. CRI can help avoid this

What i s the reversal for benzodiazepiens?

flumazenil

What is the reversal for a2 agonits?

atipamizole

Hos can you deal with dysphoria in geriatric patients?

1) rule out pain 2) very low doses of ace or dexmedetomidine

In LA, poor oxygenation during anesthesia can result in what?

postanesthetic myopathies

Why might you NOT use Ace as a premed in resp diseased patients?

it has prolonged action and relacation effects on the pharyngeal mm

What are your considerations wehn using benzodiazepiens with resp patients?

they do not have great resp depression (good), but they can produce excitement

What is a good choice of premed for sedation in ruminants?

benzo

What are your considerations when using a2 agonitss in a resp patient?

produce upper airway relaxation, so do not leave patient unobserved after premed

What are the requirements for using opioids in a resp patient, since tey depress the resp system?

patient must receive high O2 and supported by ventilation

What does Poiseuilles law say?

resistance is inversely proportional to the airway radius

What is important during the recovery of a resp patient?

provide O2!

Which patients are at risk of “air trapping” and what is this?

asthmatic, recurrent airway obstruction, bronchoconstriction. Air trapping is where alveoli is not able to push out gas and thus gets disteneded

What are the two biggest concenrs with patients with resp issues?

hypoexmia/hypoxia and hypercapnai