Old anesth good to know notes Flashcards
Anesthetic drugs work at the level of ? to produce reversible CNS depression
Spinal cord
Unconscious animals can produce complex movements at the level of the ? or ? when anesth
brainstem or spinal cord
T/F pain is a conscious experience therefore anesthetized animals DO NOT feel pain
True
What are the ASA stauses?
ASA 1- normal healthy p, routine procedure or simple fx
ASA 2- brachycephalic dog, has systemic issue but fully compensated and under control,
ASA 3- serious systemic illness, stable vital signs
ASA 4- involved, hospitalized, serious systemic dz not compensating at all
ASA 5- gonna die like GDV or perf/septic FB
What are some factors increasing MAC???
hyperthermia, CNS stimulants, chronic drug use, red hair in humans
Why is the amount of inhalant needed to produce unconsciousnes less than 1/2 the amount needed to produce immobility?
Because the primary site of anesthesia to produce immobility is in the SC not the Brain
Low B:G means more or soluble or insoluble in blood?
INSOLUBLE
T/F anesthetized p can do respond physiologically and anatomically to noxious stimuli?
T
Can noxious stimulation cause movement in unconscious animals?
YESSS
deep anesth will decrease what 3 things?
will decrease CO, BO, and tissue/organ perfusion
Doppler is ___ but oscillometeric BP is ____
indirect; direct
Blood pressure =
Q x R
Q is flow and R is resistance
What are normals for adult animals systolic, diastolic, and MAP?
Systolic= 100-160
Diastolic= 60-90
MAP= 60-100
Does oscillometric or doppler provide systolic, diastolic, MAP and HR?
Oscillometric BP
Doppler only provides _____ valves
systolic
Arterial BP =
HR x SV x SVR
90% of SpO2 means ___ PaO2
60 PaO2
Capnographs are accurate predictors of ____ in ventilated p
PCO2
How do we know p is in stage 3?
loss of righting reflex
What is a possible cause of VPC’s?
Catecholamine release from high stress patient
propofol side effects?
Vasodilation/hypotension, bradycardia, impaired baroreceptors (p hypotensive and cannot compensate with increasing HR), decreased RR and TV (apnea)
What is a good premed and induction choice for puppy ASA status 1?
Ace + methadone IM, IVC, induce with prop and maintain on Iso and O2
premeds for healthy colt undergoing castration?
Premeds Xylazine and torb, induce with ketamine and midazolam IV and maintain on Sevo and O2
What is the best induction for greyhounds?
Propofol
T/F Pain is always subjective, unpleasant, detrimental to health and necessitates tx?
TRUE
T/F one must be conscious to perceive pain.
Trueee
What is the main MOA of opioids?
bind to opioid receptors and activate anti-nociceptive neurons
What is the difference between full agonist opioids and partial agonist opioids??
Full agonist opioids- bind to and activate, without ceiling effects
partial agoinst- activates some or all of the receptors, HAS A ceiling effect
MAP =
CO =
MAP= CO x SVR
CO= HR x SV
how can we increase MAP
1st- turn down inhalant if p too light
2nd- give IV fluid bolus of crystalloids (25% of 1 blood volume to start)
90 mL dog
60 mL cat
use crystalloid bolus to increase ____ and use colloid bolus to increase _____
HR; vasculature
unlike crystalloids, colloids increase ?
plasma oncotic pressure
hypertonic saline is most useful in what situation? How does it work and how much do we need?
useful in acute hemorrhage; use small volume like 4mL/kg and causes rapid increase in plasma volume by pulling water from interstitial space into the vascular space
BUT INTERSTITIAL SPACE NEEDS TO BE REPLACEDDD
What if MAP is low and crystalloid, colloids, and hypertonic saline all do not work??
Start inotrope infusion (improves perfusion, may increase MAP by increasing heart contractility)
dobutamine, dopamine are most commone
Are iontropes and vasopressors the same thing? How are they different??
Intropes are to improve heart contractility whereas vasopressors are used to change the pipe/vessel size
pressors are ephedrine, phenylephrine, vasopressin, norepi, high doses of dopamine
intropes are dobutamine and dopamine
The abdomen is filling w blood, what do we do?
Maintain circulating volume with quick crystalloid infusion, prolong crystalloid with colloid, blood transfusion if needed
Hypoventilation is PaCO2 less than __mmHg
Hypoxemia is SPO2 less than _____; PaCO2 less than ____ mmHg
Hypotension is MAP less than ___ mmHg
Hypoventilation is PaCO2 less than 45mmHg
Hypoxemia is SPO2 less than 85-90% PaCO2 less than 60-80 mmHg
Hypotension is MAP less than 60mmHg
What is brachycephalic syndrome?
Stenotic nares. elongated soft palate, everted laryngeal saccules, hypoplastic trachea, high vagal tone, excessive pharyngeal tissues
premeds and induction agents for larpar dog:
Ace and torb
Induce with prop
___ is better to increase BP than ____ (fluids)
Colloids; crystalloids
Plan to tx hypotension!! ***
Decrease inhalant
give crystalloid bolus (3-10ml/kg) repeat x1 if necessary
then give colloids (5ml/kg) over 5-10 minutes
if that did not help and P DID NOT lose any blood, give a vasopressor (ephedrine. phenylephrine)
Avoid ____ (a drug) in Boxer dogs
Acepromazine
how is the neonatal circulatory system different than adults?
low pressure, volume, and peripheral resistance
What drug does not have much affect on neonatal p?
Atropine (reverse the drug if causing too low of HR)
neonatal BP is lower or higher than adults?
Lower
what are the negative consequences of hypothermia?
Bradycardia, decreased CO and BP, prolonged recovery and drugs are not as effective usually
Cardiac ____ progressively decreases with older age but ___ stays the same
cardiac output; contractility
premeds of geriatric p:
Opioids +/- low dose ace or benzo
Alpha 2 agonists
low dose ket in cats
in heart disease DOGS DO NOT use this drug but can use in CATS with HCM
Alpha-2’s
T/F all anesthetic meds are nephrotoxic but dexmed is able to protect against AKI (having said this most injectable drugs do not directly affect the kidneys)
Trueeee
How do inhalant anesth agents acutely affect renal function?
no direct effect but indirectly reduces GFR and RBF
T/F urine output is normal in anesth. dogs and does not reflect decreased renal profusion
T
What are the ECG effects of high K+?
Brady, atrial standstill, T wave may or may not be large
What e’lyte can be administered to counteract K+?
calcium salts
target MAP around __ of baseline of awake BP in neonatal p
80%
What do we assess to test the synthesis of liver function? What about regulation?
Plasma proteins, coagulation factors, glucose;
urea, BUN, lactate
Liver failure may be present w normal liver enzymes, instead what factors will be abn in reduced liver function?
Albumin, glucose, BUN, bile acids, coag.
what is the main liver test?
serum albumin
DO NOT use what drug(s) with hepatic encephalopathy?
Benzos (mid/diazepam)
Anesthetic rules of thumb for p with CV issues–>
avoid increased myocardial oxygen demand, avoid fluid overload, maintain adequate oxygen delivery, maintain HR, inotropes are great for poor contractility, do not change cardiac meds suddenly
Do not use ___ or ____ or ______ in p with HCM or CHF
acepromazine or dissociatives (ketamine in high doses); positive inotropes
What are good drugs for p with CV issues?
Benzos (mid/diazepam), opioids, local anesth.
Good anesthetic plan for DCM p:
opioid and benzo
preoxygente
prop or fent or ketamine/diazepam induction
Puppy with PDA plan
opioid + low dose ace or benzo
anticholinergics to maintain HR
Induction with low dose propofol or ketamine/diazepam
intercostal block with bup
