Anesthesia Flashcards
Of the ruminant groups (dairy, beef, and small) which need lower doses of anesthetic drugs? Two answers.
Dairy and small
What is important for a halter not to do when being used on a camelid?
Slip forward on nose, could compromise the airway and lead to stress and panic (and more hissing, kicking, spitting, and biting, how lovely)
How long should large ruminants fast to reduce their risk of tympany, regurgitation and aspiration and avoid emptying the rumen too much?
24-48 hours
Why should anticholinergic use be avoided in ruminants? Two answers.
Ileus and increases viscosity of saliva which ruminants already produce a lot of → increased risk of airway obstruction
Why is it common for camelids to be on omeprazole when they might be undergoing stress, such as anesthesia?
Omeprazole = antacid; camelids = stress ulcers
What does the degree of regurgitation in ruminants and camelids depend on?
Animal position
In which position is the incidence of regurgitation the highest?
Dorsal recumbency
What can be done when a ruminant/camelid is in a lateral position to reduce the incidence of regurgitation?
Elevate middle portion of the neck with a pillow/towel, allows any regurge that occurs to drain out of the mouth instead of going back into the oral cavity
In which position is ruminal tympany less likely to occur?
Sternal
What can distention of the rumen result in? Four answers.
Reduced lung volume, respiratory distress, hypoxemia, and decrease cardiac output
Ruminants and camelids have smaller/larger tidal volumes and higher/lower respiratory rates than dogs and cats.
Smaller, higher
What two side effects of anesthesia related to gas content of their blood are common in ruminants/camelids during spontaneous ventilation?
Hypercapnia and hypoxemia
What monitoring equipment would let you know that a patient has the abnormalities that answer the question above? (Hypercapnia and hypoxemia)
Hypercapnia - EtCO2 or blood gases; hypoxemia - pulse ox
What is the oxygen flow rate for an adult bovine patient?
15 L/min
How can dorsal/lateral positioning of a ruminant or camelids lead to hypoxemia?
Weight of abdominal viscera decreases the functional reserve capacity of the lungs which leads to a ventilation-perfusion mismatch = hypoxemia
Dorsal/lateral position of a ruminant/camelid compresses the caudal vena cava, what does this lead to?
Decreased venous return → decreased cardiac output and blood pressure
Which three nerves are more commonly affected when a ruminant/camelid is left in a dorsal/lateral position for too long with inadequate padding?
Radial, peroneal, and tibial
What do you need to ensure to prevent myopathy?
Ensure normal blood pressure
(T/F) Camelids do not have a jugular groove.
True
Which side of the neck is preferred for a jugular catheter in camelids?
Right
Why might a venous and arterial sample of blood look similar in terms of bright redness in a camelid patient?
Camelids are high altitude animals = high oxygenation even in venous blood
How can you test in a camelid patient if your catheter is in an artery versus a vein?
Open the port, if it gushes, probably an artery; isn’t vet med nice
What shape are camelid erythrocytes?
Ellipsoidal
What are alternative veins that can be used for small ruminants if you cannot hit the jugular? Four answers.
Auricular, cephalic, saphenous, and coccygeal
If you fast a calf, kid, lamb, or cria for greater than > 4 hours, what are you putting them at risk of?
Hypoglycemia
Why should you avoid excessive fasting in ruminants/camelids? Two answers.
Change in ruminal flora and risk of ketosis
Which alpha 2 agonist are ruminants very sensitive to and which can induce abortions in the third trimester similarly to oxytocin?
Xylazine
What is the dose for alpha 2 agonists for large ruminants/camelids when compared to the dose for horses?
Large ruminants → 1/10 of the dose for a horse
Why should alpha 2 agonist use be avoided in small ruminants? Two answers.
Causes pulmonary edema and hypoxemia
What side effect is associated with large doses and prolonged treatment with opioids in ruminants/camelids?
GI stasis
(T/F) Ruminants and camelids love benzodiazepines.
True
Which route of administration should be used for diazepam always?
IV
What three drugs are in a ‘ketamine stun’, which is used for standing sedation?
Butorphanol, xylazine, and ketamine
Give some examples of when you might use a ketamine stun (Dr. P listed 3 and that’s what I will list but there’s probably lots more).
Laparotomy in range cattle, endoscopy, head examinations
Are the MACs for iso and sevo lower/higher/same for ruminants/camelids when compared to small animal MACs?
Iso - lower; sevo - same
What is the weight cut off for using a small animal anesthesia machine in a ruminant/camelid?
<150 kgs
(T/F) A majority of ruminant/camelid surgical procedures are done with regional anesthesia and sedation.
True
What is the shorter acting regional block drug mixture (where morphine lasts 20-24 hours, this lasts 5 hours)?
Lidocaine and xylazine
Why is it necessary to use a stylet when intubating a small ruminant?
Their mouth is small, putting the ET tube in occludes your vision so use small stylet first then feed tube over, voila
In which species of ruminants (bovine, caprine, ovine, camelids) does the position of the eyeballs correlate well with depth of anesthesia?
Bovine
What position should ruminants and camelids be recovered in if they still have an intubation tube in?
Sternal position with head down
Why do you only want to partially deflate your cuff before extubating a ruminant/camelid patient?
The slightly inflated cuff will draw out any potentially regurgitated material and prevent it from going into the trachea
Why should you manually restrain the neck of camelids when recovering them from anesthesia?
Tend to slam their neck around, restraint can prevent trauma/injury
What is administered to camelids, who are obligate nasal breathers, to avoid nasal obstruction?
Phenylephrine nasal spray
Why are pigs difficult to restrain? Two answers.
Body shape and lack of ungraspable appendages
What are pigs susceptible to during intubation that is similar to cats?
Laryngeal spasms
What species do you find a palatal ostium that WILL get in your way during intubation?
Guinea pigs
Why are small exotics susceptible to hypoxemia, hypercapnia, and respiratory arrest?
Resp rate is normally high and tidal volume is very small; if you cut out the high respiratory rate by inducing anesthesia, the tidal volume is still very small → hypoxemia, hypercapnia, respiratory arrest
Which vein is most commonly used in pigs for administration of drugs or placement of a catheter?
Auricular
If you administer alpha 2 agonists to a pig patient, why might you then have difficulty in placing your catheter?
Vasoconstriction
Of the veins listed below, give the small exotic species that you may use it in for injections or catheter placements.
- Cephalic vein
- Saphenous vein
- Jugular vein
- Marginal ear vein
- Lateral coccygeal vein
- Cephalic vein (Hamsters, guinea pigs, rabbits)
- Saphenous vein (Hamsters, guinea pigs, rabbits)
- Jugular vein (Rabbits)
- Marginal ear vein (Rabbits)
- Lateral coccygeal vein (Rats)
Do you need to administer a higher or lower dose of alpha 2 agonists to a swine patient?
Higher
Why would you administer ondansetron or maropitant to a swine patient?
Both are antiemetics, can be given to pig patients with hx of GI issues/vomiting to prevent vomiting and subsequent aspiration pneumonia
What anesthetic depth sign is consistent across all species which makes it particularly useful in pigs who are difficult to monitor depth for?
Jaw tone
What are the triggers for malignant hyperthermia in porcine patients? Four answers.
Transport/restraint, warm temperatures, volatile inhalants, succinylcholine
What porcine breeds are predisposed to malignant hyperthermia? 6 answers.
Pietran, landrace, poland-china, large white, hampshire, yorkshire
Is EtCO2 high or low when a patient has malignant hyperthermia?
High
What should you do FIRST when you begin treating a patient with malignant hyperthermia?
Turn of inhalant
Why should you change the anesthesia machine and breathing circuits for a patient with malignant hyperthermia?
If it’s the inhalant causing the issue, you’ll be treating the issue as you continue to cause it
What drug can be administered to a swine patient with malignant hyperthermia under anesthesia by blocking the excess calcium being released?
Dantrolene
Small pet exotics have a high metabolic rate, why is that important to know? Two answers.
Hypoglycemia if fasted too long and rapid drug metabolism
Why do small exotics have a low tolerance to hypoxemia and rapid inhalant induction/elimination?
B/c they have high oxygen consumption rates
How long should adult swine patients be fasted?
12 hours
What length of needle should be used in swine patients when aiming to give IM sedation?
1.5-2 inches
(T/F) Small exotic patients should not be fasted.
True
The smaller a patient gets, the _____ (more/less) important it is to have an accurate weight.
More
Why is ketamine used alone not ideal in swine patients?
No muscle relaxation
Of sevoflurane or isoflurane, which is best for mask induction in a heavily sedated swine patient?
Sevoflurane
When should a small exotic patient be removed from an induction chamber?
Loss of righting reflex
You have a swine patient that is 217kgs, can you use a small animal anesthesia machine for it?
No, >200kgs
What drug is used for total intravenous anesthesia [TIVA] in swine patients?
Propofol
When using inhalant anesthesia in small exotic patients…
- Resistance should be ________ (lower/higher) when compared to dogs/cats.
- Non-rebreathing fresh gas flow should be proportionally __________ (lower/higher) when compared to dogs/cats.
- Resistance should be ________ (lower/higher) when compared to dogs/cats. (Lower)
- Non-rebreathing fresh gas flow should be proportionally __________ (lower/higher) when compared to dogs/cats. (Higher)
Pain assessment in swine patients is typically based on changes in what?
Behavioral changes
What are the four contributing factors for anesthetic mortality in equine patients?
Age, duration of surgery, drugs for sedation, and inhalants
What arrhythmias are common with equine patients that should be known prior to anesthesia?
1st and 2nd degree AV blocks and atrial fibrillation
Why is it important to rinse a horse’s mouth out prior to anesthesia?
Can store lots of bits in there that you don’t want to take down the trachea with the ET tube upon intubation
What can let you know an equine patient is adequately sedated before proceeding with your induction? Four answers.
Feet planted, head and lip dropped, minimally responsive to external stimuli
What advantage does the ketamine/diazepam combo have over the ketamine/propofol combo used for induction of equine patients?
Less volume needed with ketamine/diazepam
(T/F) Intubation in equine patients is typically blind.
True
What should be done if you are attempting to intubate an equine patient and you feel resistance?
Pull ET tube back, rotate 90 degrees and readvance
Of inhalant anesthesia and total intravenous anesthesia…
- Which causes less cardiorespiratory depression?
- Which has both a lower morbidity and mortality?
- Which has superior analgesia?
- Which has minimal drug accumulation over time?
- Which has good muscle relaxation?
- Which causes less cardiorespiratory depression? (TIVA)
- Which has both a lower morbidity and mortality? (TIVA)
- Which has superior analgesia? (TIVA)
- Which has minimal drug accumulation over time? (Inhalant)
- Which has good muscle relaxation? (Inhalant)
What plane of anesthesia is desired in an equine patient?
Light plane
What eye signs do you want to see in an equine patient in the optimal plane of anesthesia? Four answers.
Slow palpebral, strong corneal, tearing, and slow nystagmus
What types of drugs can interfere with eye signs?
Dissociatives
When can the ET tube be removed in an equine patient?
At swallowing or earlier
What is one of the most common complications during anesthesia besides hypotension?
Hypothermia
What bodily changes occur that cause hypothermia in anesthetized patients?
Decreased heat production and increased heat loss
Are smaller or larger patients more likely to have hypothermia?
Smaller
(T/F) It is much easier to rewarm a patient post operatively rather than prevent heat loss.
F, other way around
(T/F) Hypothermia during anesthesia can decrease healing post operatively.
True
You will need to decrease/increase your anesthesia (whether inhalant or injectable) when your patient is hypothermic.
Decrease
How much does shivering increase oxygen consumption?
400%
What heart abnormalities are associated with hypothermia?
Arrhythmias
What can you use to keep heat in a patient you are taking an MRI on when heating equipment is not MRI compatible?
Bubble wrap
What class of drugs can cause hyperthermia in cats?
Opioids
Do your anesthetic requirements increase or decrease with hyperthermia?
Increase
At what temperature and higher does CNS injury occur?
More than 107
What are the two goals of anesthetic monitoring?
To give early warning to the practitioner to maximize patient care and avoidance of human errors
What is your most important anesthetic monitor?
Trained assistant/LVT
What are the 5 constant anticipated problems in an anesthetized small animal?
Hypotension, hypothermia, bradycardia, hypoventilation, and pain
What are the three ways you can identify an anesthetized patient is hypoventilating?
Respiratory rate, chest excursions, and high end title CO2
How do you treat hypoventilation in an anesthetized patient?
Adjust anesthetic depth → decrease; manual or mechanical ventilation
What are the two locations to take a temperature in an anesthetized small animal patient?
Rectal or esophageal
How would you minimize/treat hypothermia in an anesthetized patient? Two answers.
Minimize loss, use active warming devices
How can you determine if an anesthetized animal is bradycardic? Four answers.
Esophageal stethoscope, pulse palpation, ECG, pulse oximetry
How can you treat bradycardia in an anesthetized patient? Three answers.
Decrease anesthetic depth, anticholinergics, sympathomimetics
What do you depend the use of invasive versus noninvasive blood pressure monitoring in a small animal patient on?
Criticality of the patient
How do you treat hypotension in an anesthetized patient? Three answers.
Decrease anesthetic depth, bolus of fluids, sympathomimetic drugs → dobutamine , dopamine
How do you identify pain in an anesthetized patient?
Sympathetic stimulation from surgical stimulation → increases in blood pressure and heart rate
What drug class is used to treat pain in anesthetized patients?
Analgesics
How do you determine anemia developing in an anesthetized patient? Two answers.
Approximation of blood loss via suction bottle and/or gauze used, serial PCVs
In a patient suspected to be hemorrhaging, what can be done to aid in quick administration of blood products as needed while in surgery? Three answers.
Place second catheter, blood type/cross matching, make sure have appropriate blood products available
Why is hypoglycemia more of a worry under anesthesia than hyperglycemia?
Anesthesia masks the signs of hypoglycemia → hunger and seizures
(T/F) Diabetic patients should eat the morning of anesthesia as well as receive a fraction of their insulin dose.
True
What is the normal glucose range under anesthesia for a small animal patient?
100-300 mg/dL
What should be administered to a patient that drops below the normal anesthetic glucose range?
Dextrose
What should be administered to a patient that goes above the normal anesthetic glucose range?
Regular insulin
What are the 5 constant anticipated problems in an anesthetized equine patient?
Hypoventilation, pain, hypoxemia, myopathy/neuropathy, recovery accidents
How can you determine if an anesthetized equine patient is hypoxemic?
PaO2 and/or SpO2
How do you treat hypoxemia in an anesthetized equine patient?
Mechanical ventilation with PEEP (positive end expiratory pressure)
How can tissue hypoxia be identified in an anesthetized equine patient?
Presence of cyanosis and increased lactate
Why is the minimum optimal MAP higher in anesthetized equine patients when compared to small animal patients?
Muscle perfusion more important in large equine patients
You should always keep extra of what drug with you pre, peri, and postoperatively when working with an equine patient?
Ketamine
(T/F) Myopathies and neuropathies can only be identified post operatively.
True
What three ways can you minimize myopathies/neuropathies in anesthetized equine patients?
Well padded surfaces and minimize pressure points, remove halter, and keep MAP >70 mmHg
