263 terms

Anesthesia Exam 1


Terms in this set (...)

non-liquified compressed gas
Substances that don't liquify at room temp regardless of pressure because the room temp is greater than the critical temp.
25-1,500 psig
At what pressure do liquified compressed gases become liquid?
A, J
What letter gas cylinder is smallest? Largest?
What letters of gas cylinders attach directly to the machine?
What letters of gas cylinders enter through a pipeline system?
E, H; E
What letters of gas cylinder tanks are used in North America? Worldwide what is most commonly used?
pin index safety system (small animal), side spindle in index valves (large animal)
The safety system used with individual gas cylinders that prevents application of the incorrect gas onto a machine.
nitrous oxide
Name the gas used with each pin index system.
N2O, CO2; weigh the tank
What gases do not show correlation between content and the pressure gage in a gas cylinder? How do you identify the amount in the tank?
O2- green, but internationally white
Air- yellow, but internationally white and black
What are cylinder color differences for the US and international systems?
when large amounts of O2 are needed economically
When are cryogenic liquids beneficial?
quick connectors
Which adapter for the medical gas pipline system is more likely to leak?
Gas cylinder, hanger yoke, check valve, pressure gauge, pressure regulator (anything connected to/involving the cylinder)
What are the components of the high pressure system in the anesthesia machine?
1900-2200 psig
What is the system pressure in the high-pressure system of the anesthesia machine? (KNOW IT)
From the pipline inlet up to the flow meter (LOW pressure- VIP) and oxygen flush valve. Pipeline inlet, pressure indicators, flow control valves, etc.
What are the components of the intermediate pressure system in the anesthesia machine?
35-75 L/min
At what rate does oxygen flow through the flush valve:
45-55 psig
What is the system pressure in the intermediate-pressure system of the anesthesia machine? (KNOW IT)
flow meter and beyond
What are the components of the low pressure system in the anesthesia machine?
ball- in the middle
bobbin- at the top
Where do you read a ball float or a bobbin in the flow meter?
14-16 psig (closest to atmospheric pressure
What is the system pressure in the low-pressure system of the anesthesia machine? (KNOW IT)
bi-metallic strip that bends one direction or the other with temperature changes
What in the vaporizer allows for temperature compensation?
the common gas outlet
Where do inhalant and bipassed O2 meet?
inspired CO2 increases by 1.5 mmHg,
minute ventilation decreases 10% or more and ETCO2 stays constant,
ETCO2 increases by 2.3 mmHg or more AND minute ventilation decreases by 5% or more
Under what conditions will rebreathing occur?
Rebreathing varies _____ with total FGF.
10-100 ml/kg/min; 200-400 ml/kg/min
What is FGF in the lower rebreathing system? higher?
mechanical dead space
The volume in breathing system occupied by gases rebreathed without change in composition.
1/3 dead space. 2/3 from alveoli
Break down the content and origin of expired gas as it is exhaled.
tidal volume (10-20 ml/kg) x respiratory rate in bpm
What is the calculation for minute ventilation?
fresh gas flow
What determines the amount of rebreathing that occurs?
3-14 ml/kg/min (near metabolic oxygen consumption of the patient)
What is the flow rate in complete rebreathing?
> 20 ml/kg/min but less than non-rebreathing (20-52, 50-100, 100-200 ml/kg/min)
What is the flow rate in partial rebreathing?
>200 ml/kg/min
What is the flow rate in non- rebreathing?
open system
Unknown FGF rate, no reservoir bag, rebreathing with CO2 absorber
semi-open system
High FGF rate, FGF exceeding minute ventilation, no rebreathing/CO2 absorber, reservoir bag present
semi-closed system
Moderate FGF rate, FGF lower than minute ventilation, reservoir bag present, partial rebreathing, CO2 absorber present.
closed system
Low fresh gas flow, equal to O2 uptake by patient (metabolic demand). Reservoir bag present; pop-off valve IS NOT closed. Complete rebreathing CO2 absorber present
decrease volume of waste gas, decrease cost, retains water vapor and facilitates humidification of inspired gas
What are advantages of the rebreathing circuit?
hoses and Co2 absorbent cause resistance to breathing (harder to breathe), dead space in hoses may be greater than in non-rebreathing circuits (so if you change flow rate it will take time for whole system to prime), inspired concentration lower than vaporizer % when low O2 infusion rates used
What are disadvantages of the rebreathing circuit?
fresh gas flow,
minute ventilation
To prevent rebreathing, __________ must be higher than ______.
minimal resistance to breathing, the volume of the system is very small (so any changes in flow rate will cause instant effect), don't need to use soda lime (CO2 absorbent) so decreased cost/dust/breakdown products.
What are advantages of the non-rebreathing circuit?
cold and dry inhaled air causing hypothermia/mucosal desiccation, High O2 flow causes more vaporization of ax gases, so requires more pollution management and increased cost of ax gas and O2
What are disadvantages of the non-rebreathing circuit?
Inspiratory limb inside expiratory to reduce bulk and help warm gases prior to inspiration
5-10 times (10-20 ml./lg) making it the patient's minute volume
What multiple of tidal volume is contained in the reservoir bag?
adjustable pressure limiting valve, overflow, pressure relief valve
Another name for the pop-off valve?
color change (temporary, heat and pH dependent) and becomes hard
How do you know when a CO2 absorber is exhausted? (KNOW)
larger patients, low flow rates
What factors increase the rate of exhaustion of a CO2 canister?
sevoflurane; nephrotoxic
What anesthetic becomes compound A at high concentrations and low flow rates? What is this a concern?
fresh gas inflow;
system volume
What value is change in anesthesia concentration proportional to? Inversely proportional?
What class Mapleson breathing system is this?
What class Mapleson breathing system is this?
What class Mapleson breathing system is this?
What class Mapleson breathing system is this?
What class Mapleson breathing system is this?
What class Mapleson breathing system is this?
What class Mapleson breathing system is a Bain?
What class Mapleson breathing system is a Magill?
What class Mapleson breathing system is a T-piece?
What class Mapleson breathing system is a Jackson-Rees?
Scavenge system where wasted gas goes to open area or charcoal filter; NOT used in large animals due to inefficiency and gas wasted.
Scavenge system that requires a vacuum pump connected to special scavenger system on ax machine.
monitoring is continuous, recording is intermittent
What is the difference between monitoring and recording?
What system is the cause of the most anesthetic morbidity/mortality?
may tell you something is wrong (arrhythmia) but not exactly what is wrong. It gives you the first piece of the puzzle and you have to figure out what you need from there
What is a limitation of cardiovascular auscultation?
cat: 100-220,
dog: 50-160,
horse: 25-50
What is normal HR for: cat, dog, horse?
stress/excitement, light ax plane, PAIN, hypovolemia
What are causes for tachycardia under anesthesia?
vagal stimulation, deep ax plane, drugs, arrythmia
What are causes for bradycardia under anesthesia?
What level of acute loss will result in shock?
cat: 50 ml/kg,
dog: 90 ml/kg,
horse: 75 ml/kg
What is normal blood volume: cat, dog, horse
only tells you about electrical activity, electricity/motion severely interfere with results
What is the limitation of the ECG?
What value will remain normal up to 5 minutes after an animal has been euthanized?
80-160 mmHg
What is normal SAP?
60-120 mmHg (70 in horses!)
What is normal MAP?
must maintain blood flow to the musculature as well as the kidneys
Why is minimum MAP for horses higher than other species?
40-90 mmHg
What is normal DAP?
deep ax plane, bradycardia, hypovolemia, vasodilation
What are causes of hypotension under anesthesia?
light ax plane, pain, disease (hypothyroid, pheochromocytoma, etc.)
What are causes of hypertension under anesthesia?
oscillometric monitor; every 3 minutes
What type of cardiovascular monitor cycles on its own? How often?
cuff width should be 40% circumference of the leg
How do you judge the appropriate size of cuff to use with an oscillometric monitor?
incorrect size will increase pressures artificially, placement too far from the heart is less accurate, may read when not on a patient, and may be inaccurate with cats/ exotics
What are limits of oscillometric monitors?
deep ax plane, drugs (NMBA, opiods)
What are causes of bradypnea/apnea under anesthesia?
light ax plane (pain), hypercapnia, hyperthermia
What are causes of tachypnea under anesthesia?
obstruction, ketamine
What are causes of dyspnea/poor compliance under anesthesia?
Saturation based on red/infrared light absorption. Subtracts out non-pulsatile blood.
How does the pulse-ox measure?
hemoglobin saturation (NOT oxygenation, ventilation, or perfusion!)
What does the pulse-ox tell you?
What is a normal pulse-ox level?
low/no O2, cardiac arrest/poor circulation, hypoventilation, V/Q mismatch
What are reasons that a pulse-ox might not function?
What monitor is able to provide accurate readings in the midst of CPR?
Capnograph where the sensor is in the box sitting outside the tube.
bulky and pulls on tracheal tube, sensor is easily damaged/dirtied
What are limitations of a mainstream capnograph?
Capnograph that suctions a small amount out of the tube up to your monitor.
may become kinked or clogged, must scavenge waste, delay in measurement (long tube)
What are limitations of a sidestream capnograph?
35-45 BPM
What is normal RR?
increased CO2 production due to hyperthermia/shivering, decreased CO2 elimination due to hypoventilation, expired sodasorb, or V/Q mismatch
What are reasons for hypercapnia under anesthesia?
decreased CO2 poduction due to hypothermia or cardiac arrest,
increased CO2 elimination due to hyperventilation/panting, leak in the line
What are reasons for hypocapnia under anesthesia?
What reading of a capnograph is representative of what is happening in the blood?
cardiac oscillations; the heart is bouncing on lung on expiration and the lines correspond with the pulse
What is occurring to produce this capnograph?
patient is on a ventilator and is trying to breathe against it
What is occurring to produce this capnograph?
a patient is breathing on its own
What is occurring to produce this capnograph?
a tracheal tube leak
What is occurring to produce this capnograph?
obstruction (slow change)
What is occurring to produce this capnograph?
the esophagus is intubated (gas from stomach)
What is occurring to produce this capnograph?
rebreathing system with soda-sorb, stuck butterfly valves, etc.
What is occurring to produce this capnograph?
blood gas analysis; very finicky
What is the most precise method of measuring the respiratory system under anesthesia? Why is it not commonly used?
must cap and run samples immediately, expensive, requires lots of maintenance
What are limitations of blood gas analysis?
oxygen and CO2 content of the body
What does the measurement of blood gas ultimately tell you?
Hb saturation
What does the measurement of pulse-ox ultimately tell you?
ventilation (NOT oxygenation)
What does the measurement of a capnograph ultimately tell you?
plane 1
What ax plane: analgesia and disorientation
Stage II
What ax plane: involuntary excitement & unconsciousness
Stage III
What ax plane: general anesthesia
Stage IV
What ax plane: overdose
Eye reflex and position (palpebral vs corneal), swallowing, muscle/jaw tone, response to surgical stimulation, respiration, BP, vitals
How can depth of anesthesia be represented?
test with palpebral
How can you differentiate if the eye position is light or dark ax plane?
light ax plane
What does nystagmus indicate?
minimum alveolar concentration
Amount of inhalant gas in which 50% of patients will not move with surgical stimulation.
5% less
For each degree of temperature a patient loses, it needs _________ MAC
increase their temperature
A patient is 92 degrees and bradycardic. They have an arrythmia and are very ill. What is the most important thing to do to help them to recover?
What percentage of anesthetic deaths occur i the post-anesthesia period?
the partial pressure of the dissolved oxygen in arterial blood
Define PaO2
the partial pressure of the dissolved carbon dioxide in arterial blood
Define PaCO2
the combined amount of dissolved oxygen and hemoglobin-bound oxygen in the blood
What is oxygen content?
Low levels of oxygen in the blood
High levels of CO2 in the blood
low FiO2, hypoventilation, increase in venous admixture
What are the main causes of hypoxemia?
What are the main causes of hypercapnia?
-5 to -10
What is the range of values in cmH2O for the end of expiration to end of inspiration for the lung as a whole?
-1 to 1
What is the range of values in cmH2O for the end of expiration to end of inspiration for the alveoli?
tidal volume (VT)
The amount of air moved in and out of the lungs during each breath
10 - 20 ml/kg
What is a normal range of values for tidal volume (VT)?
inspiratory reserve volume
The volume of air that can be inspired above the normal tidal volume
inspiratory capacity
This is the amount of air that can be inhaled when distending the lungs to the maximum amount
expiratory reserve volume
The amount of air exhaled by maximum expiratory effort after tidal expiration.
residual volume
The air remaining in the lungs after the most forceful expiration.
functional residual capacity
This is the amount of air remaining in the lungs after a normal expiration.
25-50 ml/kg
What is a normal range of values for functional residual capacity?
minute ventilation
Tidal volume x respiration rate=
vital capacity
The amount of air moved in and out of the lungs with maximum inspiration and expiration.
physiologic dead space
What is the air that remains in the airway and alveoli combined known as?
total lung capacity
The volume of gas occupying the lungs after maximum inhalation.
the portion of air in the airway that remains in the chain on expiration
What is anatomic dead space?
functional residual capacity
What natural airway space is the reservoir for storing oxygen and inhalants?
functional residual capacity
What may these conditions decrease? obesity, ascites, GDV, pregnancy
total pressure x concentration of O2
What is the partial pressure of oxygen?
100 mmHg
What is PAO2 in room air?
higher PaO2 results in higher hemoglobin saturation
What is the relationship between PaO2 and hemoglobin saturation?
if they are anemic or have dysfunctional forms of hemoglobin
How can a patient have adequate PaO2 and still be hypoxemic?
95%; 80 mmHg
What is your target value of SPO2 on pulse-ox? What does this correspond to?
altering ventilation only (we cannot change production)
How can you alter PaCO2?
There is a 5-10 mmHg difference
What is the relationship between ETCO2 and PaCO2?
80 mmHg (SpO2 95%)
What value is the cutoff for hypoxemia with PaO2?
60 mmHg (SpO2 90%)
What value of PaO2 does an animal need oxygen therapy?
anesthesia decreases the sensitivity of chemoreceptors responsible for regulating CO2 levels, so more CO2 is required to initiate ventilation
What is the confounding factor about hypercapnia with anesthesia?
decreases functional residual capacity significantly
What does changing the position of a large animal or obese small animal do to their respiratory abilities?
venous admixture
The fraction of blood that bypasses the alveoli and doesn't get oxygenated in the lungs.
diffusion barrier impairment, V/Q mismatch, anatomic shunt
What causes increase in venous admixture?
dead space, shunting
What may cause V/Q mismatch?
causes ventilation without perfusion
How does dead space cause a V/Q mismatch?
good perfusion but poor ventilation
How does shunting cause a V/Q mismatch?
the higher the fraction, the lower the available oxygen in arterial blood
What is the relationship between venous admixture and available oxygen in arterial blood?
difference between PAO2 and PaO2; YOU must calculate this!
What is the alveolar arterial gradient?
hypoventilation or low fraction of oxygen in air being inhaled
If breathing room air, what does a alveolar arterial gradient of <15 mmHg indicate?
venous admixture
If breathing room air, what does a alveolar arterial gradient of >15 mmHg indicate?
room air FiO2= 21%; ax machine FiO2= 100%
What is the difference between the FiO2 of room air and that from an ax machine?
ax machine is 5x as much
What is the relationship between the inspiratory fraction % of room air compared to an ax machine?
100mmHg in room air, 500 mmHg in ax machine (at least)
What is the difference between the PaO2 of room air and that from an ax machine?
>500 mmHg
What is a normal value for venous admixture if FiO2 is 100%.
500-300 mmHg
What is a value indicating mild hypoxemia for venous admixture if FiO2 is 100%
What is a value indicating moderate hypoxemia for venous admixture if FiO2 is 100%
<200 mmHg
What is a value indicating severe hypoxemia for venous admixture if FiO2 is 100%
FiO2 is 1, so PaO2 determines the value
Hoe can you determine the venous admixture if you calculate with an FiO2 of 100%?
it initiates ventilation, and it can alter the pH of the body rapidly if not treated
Why are we concerned about CO2 levels?
intermittent mandatory ventilator
What kind of ventilator do we use to completely control inhalation and exhalation without the help of the patient?
assisted-synchronized ventilation
What kind of ventilator do we use to make breaths initiated with the help of the patient?
1 carries mixture of inhalants that goes into the patient. The other is used to drive the bellows that drive mix into the patient- this should NEVER have inhalant in it because it never goes to the patient (40-60 psi)
Explain the contents of a double circuit ventilator.
bellows move up during expiration
What are ascending bellows on a ventilator?
bellows move down during expiration
What are descending bellows on a ventilator?
time, pressure, volume
What factors can be used to limit a ventilator?
flow x inspiratory time
What is the equation for tidal volume?
When you over-inflate the lungs, causing stress on the walls and capillaries.
>40-70 cm H2O
What pressures cause barotrauma to the lungs?
When stretching of the alveoli produces pressure that triggers inflammation, causing pulmonary edema.
decreased venous return, decreased preload, increased afterload, decreased cardiac output
What are the consequences of mechanical ventilation on the cardiovascular system?
What is the ASA PS for an OHE, castration, or declaw?
What is the ASA PS for a skin tumor, fracture w/o shock, uncomplicated hernia, localized infection, or compensated heart disease?
What is the ASA PS for fever, dehydration, anemia, cachexia, or moderate hypovolemia?
ASA pS 4
What is the ASA PS for uremia, endotoxemia, severe dehydration/hypovolemia, anemia, cardiac decompensation, emaciation, high fever?
What is the ASA PS for extreme shock/dehydration, terminal malignancy or infection, or severe trauma?
What is the ASA PS for a normal, healthy patient?
What is the ASA PS for a patient with mild systemic disease?
What is the ASA PS for patients with severe systemic disease?
What is the ASA PS for patients with severe systemic disease that is a constant threat to life?
What is the ASA PS for moribund patients not expected to survive 1 day with or without operation?
What ASA PS score do dehydrated animals immediately enter?
more likely you will have adverse events, anesthesia mortality, ICU admissions, and longer hospital stays
What does a higher ASA status mean to the patient?
stress, pain, disease, organ function
What 4 factors should be considered when assigning an ASA status?
the increased viscosity of the blood decreases blood flow to organs
What is the effect of polycythemia on anesthetic risk?
lots of drugs bind proteins, so knowing you should give less since there are less proteins there to hold onto the drug is important
What is the effect of hypoproteinemia on anesthetic risk?
What percentage of adverse effects under anesthesia were preventable with prior pre-op assessment?
What percentage of anesthetic cases experience morbidity?
hypoventilation followed by hypoxemia
What is one of the most common causes for morbidity under anesthesia?
you have a sedated animal without a protected airway
Why are induction and recovery the most dangerous times in surgery?
Which anesthetics cause the most respiratory complication?
bradycardia and hypotension
What are the most common cardiovascular complications under anesthesia?
cardiovascular or respiratory issues
What are the most common causes for perioperative mortality in small animals?
What % of mortality occurs in the post-operative phase?
trauma, brachycephalic breeds, extremes in age, higher ASA status, emergent cases, extremes of weight, increased duration of the procedure and anesthesia, smaller patient size, certain anesthetic drugs, major procedures, endotracheal intubation in cats
What are factors affecting the likelihood of mortality in anesthesia?
cardiovascular compromise 20-50% of the time, then respiratory compromise at 25%
What is the most common cause of death in large animal surgery?
Hypotension, hemorrhage, hypoventilation, hypoxemia, hypothermia, and bradycardia
What are some common perioperative anesthetic risks?
establishing an airway and monitoring cardiac function
What would you prioritize in a brachycephalic patient undergoing a castration with limited upper airway function?
cardiovascular, respiratory, liver, kidneys
Which organ systems are of greatest concern for the anesthetist?
most anesthetics result in cardiopulmonary depression, and the liver is required for metabolizing anesthetics while the kidneys are required for excretion
How are these organ systems impacted by anesthesia? (cardiovascular, respiratory, liver, kidneys)
Impaired kidney and/or liver function may prolong the duration of action or increase sensitivity of drugs, and medications that induce or inhibit hepatic enzymes can also affect rate of metabolism
How is anesthesia impacted by these organ systems? (liver, kidneys)
the cardiovascular system is depressed by anesthetics, so an anemic patient who may already be experiencing hypoxia or arrhythmia as a result of anemia could have exacerbation of these symptoms up to the point where they could be life threatening
How will anemia affect a patient during the perioperative period?
lots of drugs bind to proteins, so knowing how much to give how often is important. Also consider how to give fluids and that edema is a concern
How does hypoproteinemia affect how a patient will respond to an anesthetic?
breakdown of the blood/brain barrier may cause increased sensitivity to some drugs
How will central nervous system pathology affect your anesthesia?
drugs may last longer and may be more difficult to control temperature
How will endocrine pathology affect your anesthesia?
swine malignant hyperthermia
What malignant condition can pigs develop following inhalant anesthesia?
HYPP (? idk what it does)
What is the genetic disorder AQH carry and how can this effect patient preparation?
some drugs use fat for redistribution, so their effect will be amplified if there is no fat to sustain their release
How does having a low fat:body mass effect your anesthetic plan?
Hypoventilation (one of the most common causes for morbidity under anesthesia), then hypoxemia
What are the most common respiratory complications in dogs and cats?
induction and recovery are the most dangerous times and are the most likely times for morbidity; sedated animals that lack a protected airway during this time
When are you most likely to see anesthetic complications?
inhalants, propofol
What drugs may increase the likelihood of complications?
Bradycardia and hypotension
What are the most common cardiovascular complications in dogs and cats?
oinhalants, Opioids, Alpha-2 agonists cause bradycardia, acepromazine, Propofol (cause vasodilaion)
What drugs may increase the likelihood of cardiovascular complications?
opiods (especially hydromorphone)
What class of drugs potentiate gastroesophageal reflux?
What class of drugs can result in post-operative hyperthermia in cats?
What drugs can exacerbate hypothermia in dogs and cats?
Which of these species has the highest risk for anesthetic-mortality?
Do dogs or cats have a higher incidence of anesthetic-related mortality?
eye surgeries
Which surgical procedures may evoke a vagal stimulus resulting in severe bradycardia?
trauma, brachycephalic/terrier/spaniel breeds, age, size or weight extremes, higher ASA scores, longer duration procedure, intubation in cats
What are the major risk factors resulting in anesthetic-related mortality in small animals?
Pediatric and smaller patients are more prone to drug overdose, difficulty with intubation and intravenous access, and hypothermia; larger (heavier) patients experience more cardiovascular difficultues
How does patient size and age change the inherent risks associated with anesthesia?
pulse oximetry and capnography
Does the addition of what 2to monitoring systems can significantly reduce anesthetic-related mortality?
Why do large animals have more significant cardiopulmonary compromise when placed in dorsal recumbency when compared to that of small animals?
fractures, postoperative myopathy, and abdominal complications; these are followed by cardiovascular collapse/cardiac arrest
What are the major causes of equine-related anesthetic deaths?
within 24 hours of anesthesia
When are complications most likely to occur during the large animal perioperative period?
anesthetic overdose, increased duration of procedure, emergency procedures, GI surgery, dorsal recumbency, age extremes, hypotension
What are the major risk factors that result in large animal anesthesia mortality?
Aspiration pneumonia, bloat, and impaired ventilation and oxygenation
What are the risks of not fasting patients prior to anesthesia?
they may become hypoglycemic and increase risk of perioperative complications
Why do we not fast small rodents and birds?
What are the potential risks of anesthetizing a dehydrated patient?
sedation/anxiolysis, cardiovascular stability, preemptive analgesia
What are reasons for premedicating a patient?
A drug that provides the feeling of relaxation/calmness is known as a ____________.
A drug that provides anxiolysis and decreased response to external stimuli is known as a ____________.
tranquilization, sedation (NO ANALGESIA)
tranquilization, sedation, analgesia: Which of these are produced by phenothiazines?
Name the drug class described: Blocks action of dopamine in the brain; increases currents of K moving into the cell which causes hyperpolarization. This prevents depolarization of the neurons, resulting in the effect.
IM: 10-30 min,
IV: 5-15 min,
DOE: 4-6 hours
Compare the onset IM and IV of acepromazine and its duration of effect.
effect caused when the analgesic action of opiates is potentiated as the sedative effect of acepromazine is potentiated when they are used in combination
What is neutoleptoanalgesia?
hypotension (alpha-1 antagonist), bradycardia, anti-arrhythmogenic (decreased sensitivity to catecholamines which cause arrhythmias), hypothermia (vasodilation + hypothalamic effect), possible decrease in PCV
What is the effect of acepromazine on the cardiovascular system?
splenic engorgement
What is the effect of acepromazine on the GIT?
minimal unless combined with opiates
What is the effect of acepromazine on the respiratory system?
What drug is known to cause priapism, and thus should be avoided in stallions?
decreases amount of ax needed to induce and maintain animal under sedation by 25-50%, antiemetic (closes LES due to affect on dopamine)
What is the benefit of using acepromazine with anesthesia?
Yes- it can cross the BBB and placenta
Is acepromazine lipoplilic? What is the effect?
high lipid solubility allows things to quickly cross the BBB
What allows drugs to have more rapid onset as injectable anesthetics?
no environmental pollution, little equipment, cheap and easy
What are some benefits of injectable anesthetics over inhalants?
can't retrieve once administered, weight dependent, high doses required when done alone, potential for abuse or accidental self-administration
What are some disadvantages of injectable anesthetics over inhalants?
faster arrival at the brain, but faster metabolism
What is the effect of high CO on injectable anesthetics?
higher protein binding means more drug is bound to protein leaving less free in the circulation to result in a greater response and prolonged elimination
What is the effect of ionization and protein binding on injectable anesthetics?
when it reaches the brain
When do you see unconsciousness with injectable anesthetics?
redistribution to the tissues (NOT metabolism!)
What causes patients to wake up with injectable anesthetics
less blood supply, larger compartment for distribution, lack of lipophilic properties
What factors of a longer time constant affect redistribution?
A substance that is a mixture of 2 phases at room temperature.
Will an inhalant with higher blood/gas solubility require more or less time for an animal to become anesthetized?