SGT SUP Flashcards
what class of drugs does atropine belong to?
anticholinergics
what is the main use of atropine in vet anesthesia?
prevent and treat bradycardia
decrease salivary secretions
what anesthetic emergency would atropine be reached for in?
cardiac arrest
what anticholinergic has a similar use to atropine?
glycopyrrolate
how does glycopyrrolate differ from atropine?
slower onset w/ longer durtion
safer to use in heart patients
when considering your patient’s BP prior to administering an anticholinergic - what values would suggest use of atropine (vs. glyco)?
atropine - low HR and BP
glyco - low HR but good BP
why is atropine contraindicated for use in heart patients?
can cause cardiac arrhythmia
if you have Dexmedetomidine on board what do you need to do BEFORE giving an anticholinergic (ace or glyco)?
administer a half dose of reversal BEFORE giving anticholinergic
what is the main use of acepromazine?
as a sedative
t/f - acepromazine has excellent analgesic effects
false - acepromazine provides NO analgesia
what class of drug is safe to mix with acepromazine? (think analgesic)
opioids
what are some indications for the use of acepromazine?
cardiac patients - protect against arrhythmias; decrease cardiac output
mild antiemetic
in what specific case might you see acepromazine administered orally?
aggressive animals
is there a reversal agent for acepromazine? if so, what is it?
no reversal agent
what are some known disadvantages associated with acepromazine?
peripheral vasodilation hypotension hypothermia increased HR respiratory depression paradoxical excitement (young, healthy animals)
what contraindications are associated with acepromazine?
liver patients
penile prolapse in stallions
what altered effect is seen when acepromazine is administered in geriatrics, neonates and debilitated animals?
increased potency
what is the main use of benzodiazepines? (diazepam and midazolam)
tranquilizers
what indications are associated with the use of benzodiazepines?
anti-convulsant
anti-anxiety
calming
what is the ratio of diazepam to ketamine when used together?
1:1
t/f - diazepam is absorbed faster and has a shorter half life than midazolam
true
do benzodiazepines provide analgesia?
no
t/f - will not see paradoxical effect with use of benzodiazepines in young/healthy animals
false - it is possible to see paradoxical reaction with use
what emergency would occur if oral diazepam were administered to your feline patient?
LIVER FAILURE
what contraindications are associated with the benzodiazepines?
liver patients
kidney patients
geriatric
respiratory depression
why are benzodiazepines contraindicated for use in patients with liver disease?
they are metabolized slowly
is there a reversal agent for benzodiazepines? if so; what is it?
yes - flumazenil
under what class of drugs does dexmedetomidine fall?
alpha 2 agonists
what main purpose is dexmedetomidine administered for?
sedation
analgesia
muscle relaxation
what routes of administration are safe for use with dexmedetomidine?
IM
IV
what clinical indications might call for use of dexmedetomidine?
rapid sedation
short-acting analgesia
opioid sparing
t/f - dexmedetomidine CANNOT be reversed once administered
false - there is a reversal available
what reversal agent is available for dexmedetomidine?
atipamezole (antisedan)
what are some disadvantages that can be seen with use of dex?
bradycardia early phase vasoconstriction/hypertension late phase vasodilation/hypotension vomiting **respiratory depression**
what contraindications for use are associated with dex?
liver patients (metabolized) heart patients geriatric pediatric pregnant ill patients
what drugs make up the common solution known as “kitty magic” ?
ketamine
hydromorphone
dexmedetomidine
t/f - in comparison to xylazine, dex is less potent but more safe
false - dex is more potent and safer than xylazine
t/f - xylazine acts on the same receptors of the body as dexmeditomidine
true; both are alpha 2 agonists
t/f - if using xylazine in cattle, the dose will be greater than that used with a small animal
false - the dose for cattle is 1/10th of that for a small animal
what contraindications are associated with xylazine?
pregnant cows and ewes
liver patients
heart patients
t/f - butorphanol is not an opioid
false; it is an opioid
what is a common use for butorphanol in veterinary anesthesia?
pre-med and post op analgesic
what unique property does butorphanol possess? (think multi-use)
can be used to reverse morphine and fentanyl
t/f - butorphanol is more effective as an analgesic than a sedative
FALSE; butorphanol has poor pain control but does cause sedation
what contraindications are associated with butorphanol?
liver disease hypothyroid renal insufficiency addison's head trauma geriatric/debilitated patients
is buprenorphine administered in severe pain cases for analgesic?
no - buprenorphine is good for mild to moderate pain
which is the longest lasting opioid? how long does it act?
buprenorphine; 8 hours
what specialized form of buprenorphine is available? what unique quality does it possess?
slow-release; lasts up to 3 days
what qualities make hydromorphone superior to morphine?
greater analgesic potency
fewer side effects
longer duration of effect
fewer tendencies of vomiting
what is a common side effect that one could expect to see in their feline patient with hydromorphone on board?
hyperthermia
when should a cat be given gabapentin (if applicable) before a stressful event?
15 hours
what are the two main effects of gabapentin? (that we want to see)
decrease in anxiety
analgesic at the nerve level
what drug should ALWAYS be avoided in hypoproteinemic patients and WHY?
propofol; it is highly protein bound
what respiratory side effect can you expect to see after intubation with propofol induction?
apnea - the patient will hold their breath
if comparing propofol and alfaxalone, which has a longer duration of effect?
alfaxalone
what is the purpose of the pressure reducing valve?
reduces the pressure from the oxygen tank to a constant usable level of 40-50 psi
is the oxygen released from the tank at a safe pressure level for the patient?
NO; needs to be furthered reduced by the flowmeter
what is the purpose of the line pressure gauge? what should it read when you have turned on the oxygen tank?
indicates the pressure in the gas line between pressure-reducing valve and flowmeter; should read 40-50psi when tank is open
what is the purpose of the flowmeter? what units are used to express?
reduces pressure of gas to 15psi; expressed in L/min (gas flow to patient)
what is the purpose of the oxygen flush valve?
delivers a short, large burst of PURE oxygen into the rebreathing circuit or common gas outlet
when might you use the oxygen flush valve? is it safe to use when your patient is hooked up to the circuit?
refill reservoir bag, dilute gas left in circuit at the end of anesthesia ; NO, never use the oxygen flush while patient is hooked up
in a VOC, does oxygen from the flowmeter enter the breathing circuit before or after the vaporizer?
oxygen from the flowmeter will enter the breathing circuit AFTER the vaporizer
what part of the anesthetic machine is connected to both the vaporizer outlet port and the breathing system?
common gas outlet
t/f - our smallest patients need to be set up with a rebreathing circuit for anesthesia
false - any patient <7kg requires a non-rebreathing circuit
what is dead space?
gas that is inspired at every breath but does not participate in gas exchange
what is animal dead space?
anatomical dead space of the animal; space from the mouth (circuit enters) to alveoli (gas exchange)
what is mechanical dead space?
space from the animal’s mouth to the machine
what are some possible causes of circuit resistance?
valves
absorbent canister
hose length, diameter
what is circuit drag?
refers to anything that may cause extubating of the patient
what is the purpose of the unidirectional valves?
control the direction of gas flow
what is the purpose of the pop-off valve?
allows excess carrier and anesthetic gases to exit the breathing circuit and enter the scavenging system
what are some indications for manual ventilation? (bagging)
minimize chance of atelectasis (every 5-10min)
normalize gas exchange
regulate depth of anesthesia
what happens with the carbon dioxide canister?
soda lime granules react with CO2 to form calcium carbonate
what is a physical sign (on your patient) that you may be using depleted soda lime granules?
cherry red mucous membranes; isoflurane mixed with depleted granules creates excessive heat and carbon monoxide
what is the purpose of the pressure manometer?
indicates the pressure of gases within the breathing circuit
what level on the pressure manometer should NOT be exceeded when manually ventilating? why?
20 cmH2O; to prevent excessive pressure in the lungs
what are the three options for scavenging systems?
passive
active
activated charcoal canister
what kind of scavenging system uses a vacuum pump function?
active
describe the F circuit
rebreathing circuit
coaxial tubing to warm inspired air with expired air
describe the coaxial circuit
used for specific anesthetic machines
rebreathing circuit
coaxial tubing
has less resistance than the F circuit d/t one less piece of tubing
describe the coaxial bain circuit
non-rebreathing
coaxial tubing
requires a universal control arm
what are the two disadvantages known to be associated with the Ayres T-piece?
no pressure manometer (no universal control arm)
need to ensure reservoir bag remains flat (not folded)
t/f - endotracheal tube size is not based on lean body weight
false - ETT sizing is based off of lean weight
how do you calculate the appropriate sized reservoir bag for your patient?
tidal volume (10-20ml) x 6
what must your flow rate ALWAYS remain above?
500ml/min
how would you calculate a mask flow rate?
tidal volume x 30
what are the common induction and maintenance flow rates for a rebreathing system?
induction: 50-100ml/kg/min
maintenance: 20-40ml/kg/min
what are the common induction and maintenance flow rates for a non-rebreathing system?
induction:
maintenance: 200-300ml/kg/min
when performing anesthesia, are we looking for a low or high blood-gas partition coefficient? why?
low; faster induction/recovery, agent is more soluble in alveolar gas than in blood at equilibrium
high concentrations in pulmonary alveoli lead to steep diffusion gradient between alveoli and tissues
what is minimum alveolar concentration? (MAC)
concentration of vapour in the lungs that is needed to prevent movement in 50% of subjects (in response to surgical stimuli)
how do you measure your patient properly to choose an ETT size?
tip of ETT at point of the shoulder with the opposite side coming to the nose of the animal
what steps are required for intubation?
preoxygenate for 3-5 minutes administer IV induction agent to effect position patient in sternal recumbency assess depth of anesthesia proceed with intubation if deep enough, if not administer more induction agent
what may happen in your feline patients during intubation if proper preventative measures are not taken? what measures are these?
laryngospasms - avoided by using a local anesthetic spray on the arytenoids prior to intubating
how can you confirm the ETT is placed correctly?
visualize arytenoid cartilage on either side of tube
look for condensation in tube
watch reservoir bag for movement
palpate the neck
look at the breathing pattern on capnograph
how do you inflate the cuff of an ETT? how do you know you have inflated it enough?
inflate in 0.5ml increments using a syringe until no leak is heard when reservoir bag is squeezed and pressure in the circuit is 15cm H2O
what can pale mucous membranes indicate?
blood loss
anemia
poor capillary perfusion
what do cyanotic mucous membranes look like? what might they indicate?
blue to purple; can indicate:
respiratory arrest
oxygen deprivation
pulmonary disease
what is the purpose of the pulse oximeter?
measures the saturation of hemoglobin and HR
what is a normal pulse ox reading when patient is breathing pure oxygen?
> 95%
what reading on the pulse oximeter would indicate that your patient is hypoxemic?
<90-95%
what pulse oximeter reading would indicate a medical emergency?
<85%
what are the two different types of pulse oximeter probes?
transmission
reflective
what is the difference between ventilation and respiration?
ventilation refers to the movement of gas in and out of alveoli where respiration refers to the process of oxygen being supplied to and used by tissues, and the elimination of CO2 from tissues
what is tidal volume?
the amount of air that is inhaled in a breath
what is hypoventilation?
shallow breathing
what is hyperventilation?
heavy breathing
what does respiratory character refer to?
the effort required to take a breath
what is an apneustic respiratory pattern?
prolonged hesitation between inspiration and expiration
what is the purpose of the capnograph?
measures the level of carbon dioxide in air that is inhaled and exhaled
what are the two different types of capnograph monitors?
sidestream
mainstream
what should the CO2 reading be during inspiration?
0 mmHg
what should the CO2 reading be during expiration?
35-45 mmHg
during what point of respiration is the CO2 value most reflective of the arterial values?
CO2 value at the end of expiration
what capnograph reading would indicate hypocapnia?
<35 mmHg
what capnograph reading would indicate hypercapnia?
> 45 mmHg
what must be evaluated to interpret a capnogram?
baseline value (should be 0 mmHg)
ETCO2 value
waveform shape
rate of change
describe the appearance of a normal waveform on the capnograph?
modified rectangle
what might rounding at the edges of the waveform on the capnograph indicate?
leaking cuff
partially kinked ETT
what might be the cause of a rapid loss of waveform on the capnograph?
cardiac arrest
if you see a rapid decrease in the height of the rectangles in the capnograph waveform, what might be happening to your patient?
hypotension
sudden decrease in cardiac output
if a gradual increase in the height of the rectangles in the capnograph waveform is noted, what does this mean?
hyperthermia
how often should your patient’s core body temperature be taken during anesthesia?
every 15-30 minutes
what factors influence body temperature loss during anesthesia?
shaving and skin prep
lack of shivering/decreased muscular activity
decreased metabolic rate
opened body cavity/exposed viscera
hypotension - number one reason for temperature loss
age - pediatric and geriatric most at risk
size - smaller patients lose heat faster
use of a non-rebreathing system
what are some influencing factors for hyperthermia during anesthesia?
excess internal heat administration
drug induced reactions
patient cannot dissipate heat
what is malignant hyperthermia?
excess muscle metabolism with use of some anesthetic drugs/muscle relaxants
what are the clinical signs of malignant hyperthermia?
patient becomes hot and stiff
ears turn red
increased CO2 production
tachyarrhythmias
what steps should be taken if your anesthetic patient presents with malignant hyperthermia?
immediately stop anesthesia
administer 100% oxygen
use cooling methods
treat with Dantrolene
what is assisted ventilation?
anesthetist delivers an increased volume of air or oxygen to the patient
what is controlled ventilation?
anesthetist delivers ALL air required by patient; no spontaneous respiratory effort from patient
t/f - anesthetized ventilation is the same as ventilation in awake animals
false - reduced amount of air entering and leaving lungs, decreased response from breathing centre d/t use of drugs
what are some potential problems associated with ventilation in anesthetized patients?
hypercapnia - can lead to respiratory acidosis
hypoxemia - less oxygen entering the lungs
atelectasis - decreased VT so alveoli don’t completely expand which leads to collapse
what kind of fluids are contraindicated in liver disease patients?
lactated ringers solution (LRS)
how do you calculate a fluid deficit?
body weight (kg) x % dehydration - will give you volume in L needed to correct the dehydration
what is the maintenance fluid rate for cats under anesthesia?
3ml/kg/hr
what is the maintenance fluid rate for dogs under anesthesia?
5ml/kg/hr
what fluid rate should be used post-op?
2ml/kg/hr
what are the vital signs?
heart rate and rhythm respiratory rate and depth mucous membrane colour capillary refill time pulse strength blood pressure body temperature
describe the palpebral reflex
blink reflex in response to a light touch on the medial or lateral canthus of the eye
describe the corneal reflex
retraction of the eyeball within its orbit and/or a blink in response to corneal stimulation (a drop of saline on the cornea)
describe the pedal reflex
check by firmly pinching a digit - observe if animal flexes leg/withdraws paw
describe the laryngeal reflex
epiglottis and vocal cords close immediately when larynx is touched with an object
describe the papillary light reflex (PLR)
a light is shone into one eye; both pupils should constrict even when light is only shone in one directly
describe the dazzle reflex
response to a bright light stimulus on the retinas
other than the six reflexes, what are some others ways to assess anesthetic depth in your patient?
spontaneous movement muscle tone eye position pupil size nystagmus salivary and lacrimal secretions heart and respiratory rates response to surgical stimulation
when placing ECG leads on your patient, should they be in left or right lateral recumbency?
left lateral
what ECG lead should be hooked up to the left front limb?
black
what ECG lead should be hooked up to the right front limb?
white
where is the red ECG lead hooked up to the patient?
left hind limb
