Term
| Why shouldn't thiopental be used with sight hounds? |
|
Definition
| Thiopental is lipid-soluble - sight hounds don't have a lot of fat stores - drug levels in the brain remain high - hepatic metabolism is slow - these factors delay elimination, causing overdose and long recoveries. |
|
|
Term
| What are the greatest concerns for small breed dogs being anesthetized? |
|
Definition
| Hypothermia, hypoglycemia, small veins, fluid administration, length of endotracheal tube, surgeons resting on patient |
|
|
Term
| What can we do to prevent these problems? |
|
Definition
| Administer glucose and monitor blood glucose levels - warming pads - small IV catheters - use burette or fluid pump for accurate dosage - cut ETT - see-through drape |
|
|
Term
| Concerns with obese patients |
|
Definition
| Ventilation issues (panting, difficult to keep asleep, pickwickian syndrome) and difficult to find veins |
|
|
Term
| What lab data is needed for a normal animal undergoing anesthesia? |
|
Definition
|
|
Term
| What lab data would you want for an animal with heart disease? renal disease? hepatic disease? |
|
Definition
heart disease: ECG or cardiac ultrasound
Renal disease: urinalysis: BUN
hepatic disease: liver enzymes |
|
|
Term
|
Definition
Class I = excellent = healthy
Class II = good = mild disease, no clinical signs
Class III = fair = moderate systemic illness, mild clinical signs
Class IV = poor = severe systemic illness
Class V = critical = animal not expected to live with or without surgery |
|
|
Term
How many hours are cats and dogs fasted for?
What about neonatal and small animals?
pocket pets/birds?
Horses?
Ruminants? |
|
Definition
8-12
may need supplementation
Generally not fasted
12 hours
Varies depending on size |
|
|
Term
| Why do we need to fast anesthesia patients? |
|
Definition
| Empty the stomach, prevent vomiting and regurgitation, prevent aspiration of stomach fluids, decrease weight of GI tract in large animals, prevent bloat in ruminants |
|
|
Term
How would you adjust the fluid rate for a patient with renal disease? cardiac disease?
What is the shock therapy fluid rate? |
|
Definition
increase fluids with renal disease, decrease fluids with cardiac disease
40 ml/lb/hr |
|
|
Term
Fluids used for routine anesthesia
hypoglycemia
anemia and sudden hemorrhage
hypoproteinemia
maintain intravascular volume |
|
Definition
LRS or Normosol
dextrose
blood
plasma
hetastarch |
|
|
Term
Define nociception.
What is the difference between first pain and second pain? |
|
Definition
Response to a noxious stimulus.
first pain = fast, localized, transient
second pain = slow, diffuse, persistent |
|
|
Term
| Difference between visceral and somatic pain |
|
Definition
Visceral = viscera = poorly localized, cramping or gnawing
somatic = peripheral = easily localized, aching, stabbing, throbbing |
|
|
Term
| Difference between acute and chronic pain |
|
Definition
Acute = soft tissue trauma = inflammation = adaptive role
Chronic = Persist beyond expected time frame (3-6 mos) |
|
|
Term
| Explain the 3 different parts of nociception. |
|
Definition
Transduction - noxious stimuli at nociceptor.
Transmission - propagation of nerve impulse to brain
Modulation - amplifies or decreases transmission |
|
|
Term
| transduction to perception |
|
Definition
| transduction occurs at the nociceptors - transmission via the sensory nerve fibers - modulation at the spinal cord - perception at the cerebral cortex |
|
|
Term
| Explain peripheral and central sensitization. |
|
Definition
Pain signals change over time. Peripheral sensitization lowers the response threshold - results in release of chemical mediators
Central sensitization occurs in the CNS and is responsible for wind up, hyperalgesia, and allodynia |
|
|
Term
| What are the negative affects of pain, besides ethical and social considerations? |
|
Definition
Stress response results in poor wound healing
Weight loss and neg. energy balance
Delayed recovery
Inc. post-op complications
Self mutilation
Pain can become chronic |
|
|
Term
| What are the signs of pain and dogs and how should we observe it? |
|
Definition
Observe from a distance - pain is different without human interaction.
Guarding behavior, hunched posture
Shivering/panting
Staring eyes
Sympathetic signs |
|
|
Term
| How do we see pain in cats? |
|
Definition
| Cats will hide and avoid human interaction. They will not change their body position and stop grooming themselves. They may show aggression when moved or touched. Their eyes will be squinted, and sympathetic nervous signs will be seen. |
|
|
Term
| Reason for preemptive analgesia |
|
Definition
Pain is easier to prevent than treat after it starts
Limit windup
reduce anesthetic requirements |
|
|
Term
| define multimodal analgesia |
|
Definition
| using two different classes of analgesia |
|
|
Term
Why shouldn't you give ace to an animal with blood loss or low PCV?
hepatic disease? |
|
Definition
causes splenic enlargement
Metabolized by the liver |
|
|
Term
| What is common to mix with ketamine as a strong premed for cats? |
|
Definition
|
|
Term
| What are the cardiovascular affects of alpha-2 agonists? |
|
Definition
| stimulates alpha1 and alpha2 adrenoceptors - increase in BP = vasoconstriction - increase in SVR and MAP - increase in parasympathetic tone results in 2nd deg AV block - dec. CO |
|
|
Term
| Why do alpha-2 agonists cause hyperglycemia? |
|
Definition
| decreased insulin release |
|
|
Term
| what alpha-2 agonist is often combined with butorphanol for diagnostic procedures in dogs (radiographs?) |
|
Definition
|
|
Term
| define neuroleptanalgesia |
|
Definition
| opioid combined with a tranquilizer to increase sedation and analgesia |
|
|
Term
| 3 most common sedatives to combine with opioids |
|
Definition
|
|
Term
| What are Mu and Kappa receptors? |
|
Definition
| opioid receptors in the brain and spinal cord. Kappa receptors are weaker than Mu receptors. |
|
|
Term
| What happens if morphine is administered too rapidly IV? |
|
Definition
| histamine release and hypotension |
|
|
Term
| Properties of an ideal injectable agent (induction) |
|
Definition
| rapid onset and recovery, lack of tissue toxicity, minimal cardiovascular and respiratory effects, rapid metabolism, provides analgesia, provides muscle relaxation, allows fast intubation |
|
|
Term
| Why must thiopental be injected within 15 seconds? |
|
Definition
| If given too slowly, can cause excitement |
|
|
Term
| How do you adjust the dose of thiopental if the patient is hypoproteinemic? |
|
Definition
| give less, because thio binds to proteins |
|
|
Term
Why can thio only be given IV?
Why is it contraindicated in anemic patients? |
|
Definition
causes tissue sloughing
Causes splenic enlargement, lowers PCV |
|
|
Term
Why is ketamine called a 'dissociative?'
Why is it important to use eye lube with this drug? |
|
Definition
patient is awake but unaware of surroundings
eyes remain open after induction |
|
|
Term
| Telazol has a prolonged recovery when given ____ |
|
Definition
|
|
Term
| How is a patient induced with a neurolept at MSU? |
|
Definition
heavy sedation allowing intubation
fentanyl + benzo |
|
|
Term
| How fast do you have to use propofol after opening and why? |
|
Definition
| 6 hrs - supports bacterial growth |
|
|
Term
| What happens if you give propofol too slowly or too quickly? |
|
Definition
too slowly = causes excitement
too quickly = severe apnea |
|
|
Term
Why is propofol better to use in patients with renal/hepatic disease?
Does propofol cause tissue damage if injected perivascularly? |
|
Definition
rapid hepatic metabolism and redistribution.
has other routes of elimination
no |
|
|
Term
| What are the pros and cons of mask/box induction |
|
Definition
Less stressful to animal, don't have to place a catheter (most common in cats and lab animals)
Airway not protected as quickly - increased pollution |
|
|
Term
| formula for making a solution |
|
Definition
desired strength/available strength
amt to use/amt to make |
|
|
Term
| four contraindications for the use of acepromazine |
|
Definition
| anemia, hepatic disease, hypotension, stallions (penile prolapse), skin testing |
|
|
Term
| Drugs that can cause paradoxical excitement. Why do these drugs cause excitement? |
|
Definition
diazepam, midazolam, opioids
cause release of inhibitory neurotransmitter that acts as a muscle relaxant - animal reacts to this - opioids work on the receptors in the brain |
|
|
Term
| premed drugs that cause vomiting |
|
Definition
| xylazine, opioids (morphine is the worst,) alpha-2 agonists |
|
|
Term
| premed drug that is an antiemetic |
|
Definition
|
|
Term
| Drugs that fully or partially reverse morphine |
|
Definition
| naloxone, buprenorphine, butorphanol |
|
|
Term
| Why can buprenorphine be administered mucosally to a cat and not a dog? |
|
Definition
| Cat's mouths have a more alkaline pH that allows absorption of the drug |
|
|
Term
| examples of neuroleptanalgesics |
|
Definition
dexmet and buprenorphine
midazolam and butorphanol
fentanyl and valium |
|
|
Term
| three major premedications |
|
Definition
| hydromorphone, morphine, methadone |
|
|
Term
| three main induction drugs |
|
Definition
| thiopental, propofol, ket/val |
|
|
Term
|
Definition
|
|
Term
| What is the difference between a vaporizer in the circuit and a vaporizer out of circuit? |
|
Definition
VOC = precision - animal does not breath through the vaporizer
VIC = non-precision - animal breaths through the vaporizer |
|
|
Term
| 3 ways inhalants are eliminated |
|
Definition
|
|
Term
| Which elimination method predominates for inhalants? |
|
Definition
|
|
Term
| How does minimal alveolar concentration relate to potency? |
|
Definition
MAC = min concentration of anesthetic in the alveolia that will keep %50 of healthy animals asleep.
lower MAC = more potent |
|
|
Term
| What percentage of inhalant is used to maintain surgical anesthetic depth? What do we usually start on? |
|
Definition
|
|
Term
| What physiological conditions lower MAC? |
|
Definition
| acidosis (resp. dep.), hypothermia, old age, pregnancy, drugs that depress the CNS |
|
|
Term
| Which inhalant is more potent, iso or sevo? |
|
Definition
|
|
Term
| What is the importance of the odor of an anesthetic? What inhalant smells better? |
|
Definition
| Patient may hold their breath (esp. with mask induction) - can be irritating to airways, causing sialosis or coughing - sevo is less pungent and less irritating |
|
|
Term
| Which inhalant is more often used in birds? |
|
Definition
| sevo - less irritating to resp. tract |
|
|
Term
| Myocardial and respiratory effects of inhalants |
|
Definition
myocardial = mild, decreases contractility, increases vasodilation
respiratory = moderate resp. depression |
|
|
Term
| What is vapor pressure and how does it relate to temperature? |
|
Definition
| Vapor pressure is the equilibrium point between the liquid and gas phase of volatile gases. Heat increases amount of vapor produced. The higher the vapor pressure, the higher the volatility. |
|
|
Term
| why can't sevo and iso be used in the same vaporizer? |
|
Definition
| Sevo has a lower vapor pressure than iso. Vaporizers are designed for the specific temperature to reduce the concentration of the gas that would normally equilibrate with the atmosphere. |
|
|
Term
| What is solubility, and what is its effect on changing anesthetic depth? |
|
Definition
| solubility = blood/gas coefficient. lower the solubility, the more the drug likes to stay in gas rather than dissolve in blood. Therefore, since alveolar concentration has to equal brain concentration, change is anesthetic depth is quicker with a lower solubility. |
|
|
Term
| What inhalant has lower solubility? |
|
Definition
|
|
Term
| What three factors influence the speed of gas induction? |
|
Definition
| inspired concentration, ventilation, uptake (solubility + CO) |
|
|
Term
| How does expired concentration relate to expired concentration |
|
Definition
|
|
Term
| how do you calculate a time constant? |
|
Definition
| total volume of breathing circuit / 02 flow rate |
|
|
Term
| how many time constants does it take effect a 95% change in circuit concentration? |
|
Definition
|
|
Term
| the lower the oxygen flow rate, the ______ the time constant and the ________ it takes for the anesthetic concentration to reach the dial setting |
|
Definition
|
|
Term
| advantages of inhalant anesthetics |
|
Definition
| depth of anesthesia easily changed, effect terminated by redistribution and exhalation, minimal metabolism required |
|
|
Term
| disadvantages of inhalant anesthetics |
|
Definition
| cost, pollution, need trained personnel, difficult to transport for field procedures |
|
|
Term
| Why shouldn't you use sevo in patients with renal disease? |
|
Definition
| Compound A - formed from interaction btwn sevo + CO2 + soda lime - nephrotoxin - levels insignificant at normal concentrations |
|
|
Term
| What inhalant would you use for a C-section and why? |
|
Definition
| puppies wake up quicker on sevo |
|
|
Term
| What inhalant would you use for mask/box induction and why? |
|
Definition
| sevo - go to sleep faster - allows you to get the ETT in faster |
|
|
Term
| what three factors affect the speed of gas induction? |
|
Definition
| inspired concentration, ventilation, and uptake (solubility and CO) |
|
|
Term
| What three factors affect alveolar concentration? |
|
Definition
| inspired concentration, ventilation, cardiac output |
|
|
Term
| What induction agent should not be used in cats with hypertrophic cardiomyopathy and why? |
|
Definition
| Ketamine - prevents uptake of endogenous catecholamines - harms heart |
|
|
Term
| Rank the folllowing drugs in the order of how fast you can intubate after administration. Thio, Ket/Val, propofol |
|
Definition
|
|
Term
| What history or PE findings indicate that a short period of time between induction and intubation is desirable? |
|
Definition
| Brachicephalic, head trauma, respiratory disease or distress, pregnant animals, severe myocardial disease |
|
|
Term
If you suspect an animal's stomach is full of food, how would you confirm this?
What would you recommend the veterinarian do? |
|
Definition
radiographs
cancel the surgery |
|
|
Term
| what two drugs cause splenic enlargement? |
|
Definition
|
|
Term
| 3 common causes for failure of a cuff to seal |
|
Definition
| esophageal intubation, cuff leak, ET tube is incorrect size |
|
|
Term
| Why is ketamine ok to give to dogs with renal disease but not cats with renal disease? |
|
Definition
dogs = metabolized by the liver
cats = excreted by the kidney = longer recover |
|
|
Term
| Rank the following induction drugs from best to worst for induction of patients with liver disease: Ket/Val, thiopental, propofol |
|
Definition
1) Propofol
2) Ket/Val
3) Thiopental |
|
|
Term
| What additional precautions should you take with brachiocephalic breeds during induction and recovery? |
|
Definition
| preoxygenate prior to induction, use a smaller than normal ETT, elevate head off the floor during recovery, empty stomach before extubation |
|
|
Term
| Why shouldn't you give anticholinergics with alpha 2s? |
|
Definition
| HR will increase and this will cause MAP to go dangerously high |
|
|
Term
| why do we generally avoid morphine in cats? |
|
Definition
| less effective, because secondary metabolites are not produced. Also, mydriasis may cause paradoxical excitement |
|
|
Term
| What precautions do you need to take in patients with renal disease? |
|
Definition
| Want to maintain renal perfusion; therefore, avoid hypotension (ace) and choose drugs with minimal cardiovascular effects. administer fluids prior to induction at an increased fluid rate. avoid ketamine in cats. |
|
|
Term
| how is cerbral blood flow affected by the partial pressure of oxygen, PaCO2, and MAP? |
|
Definition
For adequate CBF, PaO2 should be well above 60, CO2 should be between 30 and 40, and MAP should not be too low or too high.
If PaO2 is too low, there will not be adequate CBF, and measurements of PaCO2 and MAP will be high.
However, if CO2 levels fall too low, MAP will decrease (due to vasodilation) and there will not be enough CBF. |
|
|
Term
| normal protocol for healthy, young animals undergoing elective surgery |
|
Definition
Maintain with Iso or Sevo
Premed with ace + morphine or hydro
Induce with thio, propofol, or Ket/Val
(avoid morphine in cats) |
|
|
Term
| diagnostic procedures protocol for healthy or compromised patient |
|
Definition
Induce and maintain with propofol
Premeds:
healthy = butorphanol + ace
Compromised = butorphanol IV |
|
|
Term
| What are the main concerns for a BAL? What protocol is used? |
|
Definition
Airway is not protected, no intubation
Induce and maintain with propofol
Avoid drugs that cause vomiting |
|
|
Term
| Protocol for brachiocephalic breeds |
|
Definition
need fast induction and recovery
use propofol with hepatic disease |
|
|
Term
| What is our goal with patients that have renal disease? |
|
Definition
| We need to maintain perfusion by administering extra fluids, choosing drugs with minimal renal and cardio effects, no ketamine in cats due to renal excretion |
|
|
Term
| How do we choose the protocol for a patient with hepatic disease? What other therapeutics may be needed besides drugs? |
|
Definition
Choose drugs with least amount of hepatic metabolism. Avoid ace and thio. Avoid benzos due to risk of hepatic encephalopathy.
Choose a short-acting induction agent such as propofol or an inhalant.
Choose reversible drugs for the premed. (consider neuroleptanalgesia)
Monitor glucose levels
May be hypoproteinemic and need plasma |
|
|
Term
| protocol for hyperthyroid cats |
|
Definition
| They are usually tachycardic, hypotensive with hypertrophic cardiomyopathy. No not use ketamine. Premed with ace and an opioid |
|
|
Term
Protocol for diabetic
What do we need to monitor? |
|
Definition
premed and induction drugs that provide rapid recovery. (usually propofol and low dose ace + opioid.)
Administer half dose of insulin in the AM
Check BG every 30-60 min
Feed as soon as possible after surgery and resume normal insulin protocol |
|
|
Term
| Protocol for ocular surgery |
|
Definition
Avoid IOC, pupil constriction, osteocardiac reflex.
We want a fast induction.
Thio, propofol if hepatic disease
Anticholinergic with premed.
Remember that if a neuromuscular blocker is given, we need to breath for the patient.
No opioids in dogs except butorphanol. |
|
|
Term
|
Definition
Sevo is better than iso
Propofol for induction (fairly quick)
Low dose ace + buprenorphine (reduce vomiting)
Preoxygenate, pre-clip and prep
Decreased MAC, increased oxygen requirements
Often do local line block for speed |
|
|
Term
|
Definition
Need a fast, calm induction and maintain CBF.
Usually induce with etomidate and barbiturates - often give lido to decrease coughing and increase HR
Premed with butorphanol
hyperventilate to keep CO2 down and decrease vasodilation (and ICP) |
|
|
Term
| Protocol for throacic surgery |
|
Definition
Choose drugs with minimal cardio and resp effects, but remember that these are very painful surgeries.
Premed with fentanyl and benzos, anticholinergic, consider ace
Induce with ket/val + lidocaine (thio or prop if healthy, etomidate if sick)
- With resp. disease, secure airway as quickly as possible.
- lower fluid rate with heart disease
- preoxygenate
- clip and prep prior to induction
- If opening the chest, you have to ventilate for them. Must use a closed system. |
|
|
Term
| two drugs to avoid with splenic disease, GDV, and anemia |
|
Definition
|
|
Term
|
Definition
induce with thio, propofol, or ket/val
premed if sick: meperidine + glycopyrrolate
premed if healthy or a kitten: ace + buprenorphine
check glucose levels |
|
|
Term
| When is an animal considered geriatric? |
|
Definition
| completed 75% of its life span |
|
|
Term
|
Definition
Propofol or ket/val - no thio after age 6 or 7
select premed based on renal, cardiac, resp. findings
err on the safe side
- preoxygenate
- remember MAC is decreased |
|
|
