- Shuffle
Toggle OnToggle Off
- Alphabetize
Toggle OnToggle Off
- Front First
Toggle OnToggle Off
- Both Sides
Toggle OnToggle Off
Front
How to study your flashcards.
Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key
Up/Down arrow keys: Flip the card between the front and back.down keyup key
H key: Show hint (3rd side).h key
PLAY BUTTON
PLAY BUTTON
482 Cards in this Set
- Front
- Back
|
What is meant by a VIC designed anesthesia machine?
|
Vaporizer incorporated into the breathing system
|
|
What is the term for an anesthesia machine with the vaporizor downstream from the flowmeter?
|
VOC
|
|
What type of pressure is found at the gas cylinder of an anesthesia circuit?
|
High pressure
|
|
How do you determine the amount of N2O remaining in a cylinder?
|
Weigh it
|
|
Which O2 tank size (letter) has the largest capacity?
|
G
|
|
In the US, what color are Oxygen cylinders?
|
Green
|
|
In the US, what color are N2O cylinders?
|
Blue
|
|
Whta component of an anesthesia system controls pressure?
|
A regulator
|
|
Why aren't cylinder valves lubricated?
|
Could combust with O2
|
|
What step should be followed prior to attaching an O2 cylinder to a yoke?
|
Point the valve opening away from you, open very slightly to flush dirt away from outlet port
|
|
What system is in place to ensure that gas tanks are not attached to an improper valve?
|
Color-coding, thread sizing, pin index
|
|
What is the function of the O2 pressure gauge?
|
Indicate the pressure upstream from the regulator
|
|
Which component of the anesthesia machine reduces pressure?
|
The regulator
|
|
What is the typical machine pressure?
|
60 psi
|
|
When a machine is carrying 2 gases, what type of valves are used to prevent them from backflow?
|
Check valves
|
|
What is the purpose of the flowmeter?
|
Measure and indicate gas flow around it
|
|
On a flowmeter with a sphere indicator, where is the reading taken?
|
In the middle of the sphere
|
|
Which component of the anesthesia machine allows for a high flow of O2 from the inlet which has not passed thru the vaporizer?
|
Oxygen flush/bypass valve
|
|
A bypass valve is never used when using what type of anesthesia system?
|
Non-rebreathing
|
|
Which device is activated when O2 pressure falls to zero and flow ceases?
|
Low oxygen warning
|
|
What is the purpose of the flowmeter?
|
Measure and indicate gas flow around it
|
|
On a flowmeter with a sphere indicator, where is the reading taken?
|
In the middle of the sphere
|
|
Which component of the anesthesia machine allows for a high flow of O2 from the inlet which has not passed thru the vaporizer?
|
Oxygen flush/bypass valve
|
|
A bypass valve is never used when using what type of anesthesia system?
|
Non-rebreathing
|
|
Which device is activated when O2 pressure falls to zero and flow ceases?
|
Low oxygen warning
|
|
Opening the emergency air intake valve allows the animal to breath what type of air?
|
Room air
|
|
What is the function of the vaporizer?
|
Vaporize liquid anesthetic resulting in a diluted vapor in a carrier gas
|
|
Why is a vaporiser needed?
|
Undiluted vapors are lethal
|
|
Name the 2 types of resistance ventilators are available as...
|
High and Low resistance
|
|
What name is given to a ventilator type in which the air is pushed through the system?
|
Plenum
|
|
Older vaporiser devices use what type of air flow?
|
Draw over (suck through)
|
|
What type of vaporiser design is most commonly used?
|
Calibrated (precision)
|
|
What enviromental factors can affect vaporizer performance?
|
Temperature extremes, barometric pressue
(thymol-halothane only) |
|
What is the purpose of the scavenging system?
|
Remove waste anesthetic gases from the vicinity
|
|
Name the 2 types of scavenging systems available.
|
Active and Passive
|
|
How does an active scavenging system work?
|
It sucks!
|
|
Why are active scavenging systems the only type used in human anesthesia?
|
Able to deal with a wide range of flow rates
|
|
By what 4 methods can we deliver O2 and anesthetic inhalational agents?
|
Chamber
Face Mask ET Tube Laryngeal mask |
|
What are the 3 benefits of using an ET tube?
|
Reduce risk of aspiration
Allow admin of O2 & agent without leakage into the room Reduce contamination of room by waste gases |
|
What type of ET is used in birds and why?
|
Uncuffed- to prevent damage to tracheal rings (rings are complete, overinflation can damage them)
|
|
What feature of an ET tube can help prevent an obstruction of the tube?
|
A Murphy's eye
|
|
During surgery, what factors can affect respiratory variables (rate, tidal volume, minute volume?
|
Pain, pyrexia, depth of anesthesia
|
|
During surgery, O2 consumption is influenced by which metabolic factors?
|
Age, temperature, thyroid function, drugs, muscle tone, response to surgery
|
|
What is the amount of normal tidal volume?
|
15mlkg
|
|
Tidal volume is divided into 2 part: anatomical dead space (ADS) and what?
|
Respiratory exchange area (REA)
|
|
General anesthesia can reduce the tidal volume by how much?
|
Up to 30% reduction
|
|
What does the term apparatus dead space refer to?
|
Any dead space within the breathing system that may contain exhaled patient gas and which will be rebreathed at the beginning of the subesquent inhalation
|
|
What are the 2 most common sources of added dead space?
|
Overly long ET tubes, Y-piece of a circle system
|
|
What is meant by the term "Open Anesthetic Breathing System?
|
Pt. inhales gases directly from the anesthetic machine and exhales to the atmosphere with no rebreathing
|
|
In which type of system is there complete rebreathing of expired gas with CO2 absorbed by chemical means?
|
Closed or circle systems
|
|
What factors drive the selection of a breathing system?
|
Integral resistance of system
Controlled vs spontaneous ventilation Economy Circuit drag Ease of maint and sterilization Ease of scavenging Mechanical dead space |
|
On a non-rebreathing system (Bain and T-piece) how are expired gases removed from the system?
|
High gas flows
|
|
In small animals, what is the minimum O2 provision amount usually quoted?
|
10mlkg min
|
|
What is meant by the term "low flow anesthesia?"
|
O2 delivered slightly higher than the minimum (metabolic) requirement
|
|
If Nitrous Oxide is used in a circle system, would you adjust your O2 flow higher or lower than usual?
|
Higher
|
|
What is the criteria used for selecting the size of the reservoir/rebreathing bag?
|
Should be 3 times the tidal volume
|
|
What is the formula for calculating minute volume?
|
Tidal volume (10-15 mlkg) x respiratory rate
|
|
What is the minimum of O2 flow needed for a precision vaporizer to function accurately?
|
200 ml/min
|
|
What is the pressure of O2 when using the oxygen flush button?
|
30-50 liters/min
|
|
What formula can be used to quickly calculate minute volume?
|
Body weight / 5
|
|
How do you calculate the flow for a non-rebreathing system?
|
Minute volume x 2
|
|
At the start of inhalation anesthesia on a circle system, why do you begin with a flow that is higher than needed?
|
For rapid uptake of the agent and to flush nitrogen from the body
|
|
When collecting the pre-anesthetic history on a pt., what might nocturnal coughing be a sign of?
|
Cardiac disease
|
|
Prior to GA, how long ago should the last meal have been taken?
|
6 hours
|
|
During the clinical exam prior to GA, what might be the cause for an animal to be underweight?
|
liver disease (portosystemic shunt), malabsorption, renal disease, hyperthyroidism
|
|
A pot-bellied appearance my indicate what disease condition in a dog?
|
Cushing's
|
|
An irregular heart rate discovered during the pre-anesthesia exam, should be investigated by what procedure?
|
ECG
|
|
Obtaining a history and completing a physical exam are needed to classify the animal's anesthesia risk according to which system?
|
ASA
Amercian Society of Anaesthetists |
|
What effect might exogenous corticosteroids have on an animal undegoing anesthesia?
|
Can depress cortical function, may not be able to produce endogenous steroids in response to the surgery
|
|
NSAIDS could have what effect on anesthetic drugs?
|
Nsaids are usually protein bound and could displace protein bound anesthetics
|
|
What drugs could cause nephrotoxicity that could complicate anesthesia?
|
Antibiotics
|
|
What is the difference between a tranquilzer and a sedative
|
Both quiet the animal, a sedative produces drowsiness
|
|
Which type of drug produces sleep from which an animal is NOT readily roused by a painful stimuli?
|
Narcotic
|
|
What type of drug is a combination of a sedative/tranquilizer and a narcotic?
|
Neurolepanalgesic
|
|
What are 3 reasons for using premeds?
|
-calms pt
-smooth induction & recovery -reduces amt of drugs needed -pre-emptive analgesia -counteract undesirable effects of other drugs |
|
What are some disadvantages to using pre-meds?
|
-prolongs recovery
-respiratory depression -requires time if not given IV -altered cardiovascular function |
|
Pre-meds given by the IV route are given how long prior to induction?
|
5-10 mins
|
|
Orally, pre-meds would be given how long prior to induction?
|
60 mins for dogs and cats
|
|
For old, obese or sick animals are pre-med doses increased or decreased?
|
Decreased
|
|
Ace is in what drug class?
|
Phenothiazine
|
|
Ace provides tranquilization and what other effect?
|
Anti-emetic
|
|
Ace is an A2 receptor agonist and has what effect on vasculature?
|
Vasodilation
|
|
Ace causes vasodilation and hypotension, what effect does this have on the CVS?
|
Fall in stroke volume and cardiac output, is an anti-arrhythmic
|
|
Under which condition should Ace not be used?
|
-hypovolemia or shock
-impaired liver function -anemia -breeding stallions working |
|
Which dogs are very sensitive to Ace?
|
Boxers and giant breeds
|
|
Ace is usually given along with what other type of drug as a pre-med?
|
Opioid
|
|
An A2 agonist has what effect on vasculature?
|
Vasodilation
|
|
What effects do A2 agonist drugs have on the CVS?
|
-cardiodepressant
-reduce output -bradycardia -periph vasoconstriction followed by return to normal or lower values |
|
What effect does an A2 agonist have on the GI tract?
|
relaxation and decresed motility
|
|
In which species is Xylazine used?
|
Used in most
|
|
Which A2 agonist is used in wildlife and exotic species?
|
Medetomidine
|
|
Detomidine is used primarily in which species?
|
Horses
|
|
A2 agonists are usually given in conjunction with what other class of drugs?
|
Benzodiazepine or opioid
|
|
Do pigs require a higher or lower does of an A2 agonist?
|
Higher
|
|
What is the major side effect of using an A2 agonist?
|
Cardiovascular depression- reduced cardiac output
|
|
How does an A2 agonist produce central muscle relaxation?
|
Via inhibition of spinal interneurons
|
|
What drug is the only approved A2 agonist allowed for use in food production animals?
|
Xylazine
|
|
Along with sedation, what other 2 CNS effects does xylazine produce?
|
Emesis
Bradycardia |
|
What effect does Xylazine have on cardiac output?
|
Decreased (bradycardia, hypotension)
|
|
If xylazine is given to a small ruminant, which route of administration should be used?
|
IM, to reduce the risk of pulmonary edema
|
|
What effects does Xylazine have on the GI tract?
|
-Inhibition of motility
-reduces ruminal motility -hypersalivation in ruminants |
|
Under which condition is the use of Xylazine contraindicated?
|
Contraindicated for cows in last trimester of pregnancy
|
|
What is a potential disadvantage to using Xylazine in horses?
|
Occasional wake up without warning- can be explosive
|
|
Is Xylazine reversible?
|
Yes, with Yohimbine, Atipamezole (Antisedan)
|
|
What effect will Xylazine have on 90% of cats and 50% of dogs?
|
Vomiting within 10 minutes
|
|
What caution must be taken when using Xylazine on horses?
|
Can strike out even when sedated
|
|
Which species is very sensitive to Xylazine?
|
Goats
|
|
When is Detomidine used?
|
Horses and wild animal sedation
|
|
Compared to Xylazine, what is the CVS effect of Detomidine?
|
More bradycardia
|
|
Give an example for the use of Romfidine
|
Radiography of a horse..sedation with less ataxia than xyalzine
|
|
Medetomidine has similar effects as other A2 agonists, what effect does it have on body temp?
|
Marked hypothermia for up to 5 hours
|
|
The CVS effects of Medetomidine are profound even at low doses. What drug should Medetomidine be given with to lower the dose?
|
An opioid
|
|
Which A2 agonist is the only one used in human medicine?
|
Dexmedetomidine
|
|
How is the dosage of Dexmedetomidine calculated?
|
By body surface, not weight
|
|
Under what conditions are A2 agonists contraindicated?
|
-hypotension
-hypovolemia -myocardial disease -liver failure -urinary obstruction -cows in last trimester of pregnancy |
|
A2 agonist provide a huge drug sparing effect which means what?
|
Can reduce the amount of subsequent anesthetic doses
|
|
What are the 2 A2 antagonists used to reverse A2 agonists?
|
Atipamezole and yohimbine
|
|
Atipamezole acts in what time frame?
|
4-5 minutes following IM administration
|
|
Which drug reverses the effects of Xylazine?
|
Yohimbine (and atipamezole)
|
|
What class of drug are Diazepam and Midazolam in?
|
Benzodiazepines
|
|
When are these drugs used?
|
In babies, old, sick or debilitated animals. Also used to control seizures
|
|
On which receptors do BZ's affect?
|
GABA
|
|
What effect do BZ's have on the CVS?
|
Minimal CV depression
|
|
Do BZ's affect the respiratory system?
|
Minimally
|
|
What primary effect do BZ's have on the CNS?
|
Increase the seizure threshold
|
|
By which route should Diazepam be administered?
|
IV ..which is painful due to glycol/alcohol solvent..do NOT give IM
|
|
What prolongs the action of Diazepam?
|
Metabolized in the liver into 2 active metabolites
|
|
What are the advantages of Midazolam over Diazepam?
|
-more rapid onset
-shorter acting -water soluble -no pain on injection |
|
Which drug is the reversal agent for BZ's?
|
Flumazenil
|
|
Which drug is used as a short acting tranquilizer...primarily for pigs?
|
Azaperone
|
|
Following IM injection of azaperon, what must you do with the animal?
|
Leave undisturbed for 20 minutes
|
|
Butryophenones (droperidol and azaperone) have actions similar to what other drug?
|
Ace
|
|
Name 3 opioids which can be given as pre meds for anesthesia
|
-meperidine, morphine, methadone, hydromorphone, fentanyl, alfentanyl, buprenorphone, butorphanol
|
|
Atropine and Glycopyrrolate are classified as which type of drug?
|
Anticholinergics (antimuscarinics)
|
|
Are Anticholinergics given routinely as part of anesthesia premed in cats and dogs?
|
No
|
|
In which species are anticholinergics given routinely? Why?
|
Small furry animals...to maintain cardiac output and reduce risk of salivary secretions causing airway obstruction
|
|
In which dog breeds do some vets pre-emptively use anticholinergics?
|
Brachycephalic breeds
|
|
What effect do anticholinergics have on the CVS?
|
Tachycardia (often transitory bradycardia after initial administration)
|
|
What are the respiratory effects of anticholinergics?
|
Inhibits mucus secretions
Bronchodilation |
|
What effect do anticholinergics have on the eyes?
|
Pupillary dilation
|
|
In which species should anticholinergics NOT be used?
|
Horse and ruminants
|
|
What effect do anticholinergics have on salivation in ruminants?
|
Does not prevent salivation--makes salivary secretions more viscid: risk of ileus and colic
|
|
Anticholinergics can be combined with anticholinesterases to reverse what condition?
|
Neuromuscular blockade
|
|
What are the advantages of glycopyrrolate over atropine?
|
-doesn't cross the blood-brain barrier
-less arrhythmogenic -more potent, longer acting -does not produce ocular signs |
|
In which species is Glycopyrroltes the anticholinergic of choice?
|
Rabbits
|
|
Why should anesthetized animals always receive fluids?
|
-establish venous access
-compensate for CVS effects -replace insensible fluid loss -correct fluid loss |
|
In healthy, conscious animals, what is the best route for administering fluids?
|
Orally- let the body take care of fluid and electrolyte balances
|
|
Under which circumstances is IV fluid administration a substitute for oral intake?
|
-emergencies
-pt unwilling or unable to drink -fluid loss exceeds the capacity for oral replacement |
|
Name the 3 body compartments in regards to body water
|
-intracellular (ICF)
-interstitial (ISF) -intravascular (IVF) |
|
Which body compartment is the biggest in terms of the amount of body water?
|
ICF
|
|
What governs the distribution of the body water?
|
Osmotic gradients across semi-permeable membranes
|
|
Body water makes up how much of adult bodyweight?
|
60-65%
|
|
What is the daily maintenance water requirement for healthy dogs, cats and horses?
|
2-3 ml/kg/hr
40-65 ml/kg/day |
|
Circulating blood volume consists of what 2 components?
|
Plasma plus red blood cells
|
|
What is the circulating blood volume in a dog?
|
90 mlkg
|
|
What is the circulating blood volume in a cat?
|
60 mlkg
|
|
What separates the ICS from the ECS?
|
Cell membranes that are freely permeable to water and impermeable to most solutes
|
|
Which forces favor reabsorption of fluid?
|
Higher oncotic pressure
Lower hydrostatic pressure |
|
Which forces favor filtration?
|
Lower oncotic pressure
Higer hydrostatic pressure |
|
What determines the water content of any given compartment?
|
Number of solutes in the compartment
|
|
Define osmolarity
|
Number of osmoles of solute (molecules) per liter of solvent
|
|
Define osmolality
|
Number of osmoles of solute per kg of solvent
|
|
What is the value of normal plasma osmolarity?
|
300 mosml
|
|
What substance contribute to the osmolality of body solutions?
|
electrolytes (Na, Cl (ecf), K (icf), lactate ions
glucose urea lipids |
|
What is colloid oncotic pressure?
|
The pressure required to prevent osmosis when the solution is separated from pure solvent by a semi-permeable membrane
|
|
Do small or large molecules have a stronger colloid oncotic pull?
|
Large molecules
|
|
What is normal plasma colloid oncotic pressure?
|
20 mm Hg
|
|
What is the major electrolyte found in ICF?
|
K+
|
|
What are the major electrolytes of ECF?
|
Na+ and Cl-
|
|
50% of the body stores are in ECF, how is the balance principally regulated?
|
By the kidney (aldosterone)
|
|
What are some causes of Hypernatremia?
|
-reduced water intake
-excess water loss -overinfusion of high Na+ fluids |
|
What are the causes of hyponatremia?
|
-high volume renal failure
-vomiting/diarrhea -excessive sweating -overinfusion of low Na+ fluids |
|
The movement of K+ between ICF and ECF is linked to what?
|
Acid-base status (H+)
|
|
What are the causes of hyperkalemia?
|
-renal failure
-metabolic acidosis -severe trauma/burns -muscle damage |
|
What are the causes of hyponatremia?
|
-reduced intake
-increased loss- diarrhea -increased urinary loss- diuretics |
|
Define a crystalloid
|
Water with an added combination of small molecular weight particles (electrolytes, glucose, lactate, acetate)
|
|
Once administered IV, how much of a crystalloid remain in vessels?
|
Only 1/4 to 1/3 remains after 30 minutes...rapidly redistributes to the intravascular space
|
|
What are some examples of crystalloid fluids?
|
LRS, normal saline, hypertonic saline, detrose, D5W, normosol, plasmalyte
|
|
Colloids are larger molecules made up of what?
|
Complex sugars (starches) or proteins
|
|
Some colloids can remain in the vasculature for how long?
|
Up to 12 hours
|
|
In the case of hypoalbuminemia, what is the effect of colloids?
|
Raises oncotic pressure
|
|
What is a primary use for colloid fluids?
|
Plasma volume expanders to increase cardiac output in hypovolemic patients
|
|
Give some example of colloids.
|
-gelatin
-dextrans -pentastarch/hetastarch |
|
Give some example of blood products that can be given to deal with fluid balance.
|
-whole blood
-packed rbc's -plasma -human serum albumin -oxyglobin |
|
Which administration route is the safest for K+ supplementation?
|
Oral
|
|
Which vein is used for high volume fluid replacement?
|
Jugular
|
|
Which fluid administration route is used with old feline outpatients?
|
Subcutaneous
|
|
When giving fluids by subcu, what type of fluid should be used?
|
Isotonic, with Na+ similar to plasma
|
|
Why should dextrose containing fluids NOT be given subcu?
|
Potentially bacterial growth media
|
|
Which fluid administration route should be used cautiously but provides a large area for absorption?
|
Intraperitoneal
|
|
When is the intra-osseous fluid administration route used?
|
As an alternative to IV in small or collapsed patients
|
|
Tonicity of fluids is determined by the content of what?
|
Glucose and sodium
|
|
Fluids are defined as iso, hyper or hypotonic relative to what?
|
Plasma
|
|
During anesthesia, why are polyelectrolyte solutions used?
|
To restore ECF volume
|
|
Why do the isotonic replacement fluids contain buffers?
|
To benefit animals that have a metabolic acidosis or a normal acid-base status...also designed for pts. with renal disease, shock & trauma, diarrhea, vomiting (except pure gastric vomiting)
|
|
Balanced electrolyte solutions rapidly equilibrate across the intravascular and interstitial compartments. How much fluid needs to be given to replace an intravascular deficit?
|
3-4 times the volume of blood lost
|
|
LRS cannot be given with what other fluid product?
|
Do not give with blood...Ca2+ will activate the clotting system
|
|
Why is 0.9% NaCL called an acidifying solution even though it has Na equal to plasma?
|
Contains no buffers and can lower plasma HCO3
|
|
What are some of the potential complications of isotonic crystalloid replacement therapy?
|
-inadequate fluid administration
-volume overload -hemodilution -pulmonary injury -brain trauma |
|
What is the tonicity of a dextrose solution?
|
Hypertonic
|
|
What is the aim of dextrose fluid therapy?
|
Generally used for caloric supplementation of parenteral maintenance fluids
|
|
Hypertonic saline contains how much NaCl?
|
7.2%
|
|
Hypertonic saline causes water to move from where to where?
|
From the interstitial space to the intravaascular space...increasing intravascular volume
|
|
Why should hypertonic saline be used with caution?
|
Can cause pulmonary or peripheral edema
|
|
What effect does hypertonic saline have on cardiac output?
|
Increases it
|
|
What effect does hypertonic saline have on intracranial pressure?
|
Reduces it
|
|
What is the primary use of hypertonic saline in small animals?
|
To manage shock, brain injury and to boost blood pressure intra-operatively
|
|
What is the primary use of hypertonic saline in horses?
|
To manage shock and to "prime" the CVS before induction of anesthesia (horses are at risk of hypotension)
|
|
What are the potential disadvantage of a hypertonic saline infusion?
|
Hypernatremia
Hyperchloremia Hypokalemia |
|
How long is the effect of increased volume when hypertonic saline is given alone?
|
30 minutes
|
|
How can the effect of hypetonic saline be extended?
|
Give a colloid
|
|
What type of fluid must follow the administration of hypertonic saline?
|
An isotonic fluid....intravascular expansion is transient
|
|
If the hypertonic saline is given too rapidly, what effects might be seen?
|
Hypotension, bradycardia, brochconstriction, rapid shallow breathing
|
|
Colloids are used as plasma volume expanders and to treat hypoproteinemia. Under which condition would you NOT use a colloid?
|
Animals with pre-existing coagulopathies (may interfere with platelets and clotting)
|
|
What are the potential complications of colloid therapy?
|
-volume overload
-increased bleeding time (dilution of clotting proteins) -care required for animals in heart failure |
|
Oxyglobin is purified Hb from which species?
|
Bovine
|
|
Oxyglobin can improve oxygen transport for how long?
|
Up to 3 days
|
|
What effect does oxyglobin have on cardiac output?
|
Reduces it
|
|
When might the use of oxyglobin be indicated?
|
For the treatment of auto-IMHA
|
|
Using oxyglobin in cats can have increased risk of what?
|
Pulmonary edema
|
|
What are the golden rules of pre and intra-operative fluid therapy?
|
-Establish what sort of fluid has been lost
-Replace like with like |
|
What effects can intravascular fluid deficits (hypovolemia) have?
|
-tachycardia
-low blood pressure -vasoconstriction -pale mm -prolonged CRT -cold extremities -hyperlactatemia -decreased urine output -increased urine SG (azotemia) |
|
What effects can interstitial fluis deficits (dehydration) have?
|
-poor skin turgor
-sunken globes -dry mm -increased PCV and total solids -increased urine SG, azotemia |
|
What effects can intracellular deficits have?
|
-dull mentation
-hypernatremia -hyperosmolarity |
|
Is pure water loss common or uncommon?
|
Uncommon
|
|
Which fluid deficit situation requires immediate correction?
|
Hypovolemia- loss from the intravascular compartment
|
|
Loss from dehydration requires a fluid replacement plan with fluids given over what time period?
|
6-24 hours
|
|
What information is needed to make decisions regarding fluid therapy?
|
-history
-astute physical assessment -baseline objective data |
|
On clinical exam, how is hydration status determined?
|
-skin tugor
-moistness of mm -eye position -HR -peripheral pulse -CRT -jugular distension |
|
How is fluid balance best assessed?
|
By serial bodyweight measurement and lab tests
|
|
Name 3 lab tests in which the parameters can be influenced by hydration status
|
-PCV
-total protein -USG -BUN |
|
When examining lab results for hydration status, inflammatory disease will raise which portion of the proteins?
|
Globulin
|
|
In the case of hypovolemia, which protein value will be raised?
|
Albumin
|
|
In a case of dehydration, an elevated BUn will be accompanied by what type of change in USG?
|
Increased
|
|
What condition does an elevated BUN and a low USG indicate?
|
Renal disease
|
|
Fluid loss during anesthesia/surgery can be from what?
|
-pure water loss
-loss of mixed water and electrolytes -hemorrhage |
|
During anesthesia, how is pure water mainly lost?
|
Evaporation from exposed membranes
|
|
What are the causes of electrolyte loss during the peri-anesthetic period?
|
-vomiting
-diarrhea -sweating (horses) |
|
Why can hemorrhage lead to cardiovascular collapse?
|
Fluid lost is plasma
No change in the relative concentration of electrolytes & water, so no incentive for water to move from ISF to ICF to replace what is lost from circulation |
|
What type of fluid should any healthy animal undergoing anesthesia receive?
|
Isotonic, crystalloid fluid
|
|
What is the infusion rate for the isotonic fluid therapy during GA on a healthy animal?
|
5-10mlkg h (5 times maintenance)
|
|
This rate will not compensate for what type of fluid loss?
|
Dehydration or blood loss
|
|
For short procedures with GA, which solutions are suitable?
|
-LRS
-Plasmalyte or Normosol |
|
What is the rule of thumb for volume of fluid to compensate for blood loss?
|
3 times the volume of a crystalloid for minor hemorrhage
|
|
if hemorrhage or blood loss continues, what should then be infused?
|
Colloids
|
|
How is blood loss during surgery monitored?
|
-suction bottle contents
-gauze swabs -lap sponges -surgical drapes -surgeon's gowns -floor, table surface under drapes |
|
How do we replace blood loss during surgery when the amount is
<10% blood volume? |
With crystalloids
|
|
How do we replace blood loss during surgery when the amount is
<20% blood volume? |
With colloids and crystalloids
|
|
How do we replace blood loss during surgery when the amount is
>20% blood volume? |
With blood plus cystalloids
|
|
What is the aim of rapid fluid therapy?
|
Maintain PCV >20%, and TP >35gdl
|
|
During GA, what is the infusion what for crystalloid fluids?
|
5-10 mlkg h (higher when doing surgery)
|
|
What is the infusion rate of crystalloid fluids for treatment of shock?
|
60-90 mlkg h
|
|
At what rate should hypertonic saline be given?
|
4-5 mlkg single dose administered slowly
|
|
What is the rate for colloid fluid infusion?
|
2-20 mlkg h for intra-operative hypotension, peri-op hypoproteinemia, mild hemorrhage
(not to excedd 40mlkg h due to coagulopathies) |
|
What effects can crystalloid or colloid fluids have on hypotension during surgery?
|
-restore circulating volume,
-raise blood pressure -maintain organ perfusion |
|
Continued high rate of crystalloids cannot be continued indefinitely due to the risk of what?
|
Dilution of plasma proteins (esp albumin), reduce plasma colloid oncotic pressure, increasing loss of water from vasculature leading to edema
|
|
Post-anesthesia maintenance fluids contain what type of levels of Na, CL and K?
|
Na low
Cl low K high |
|
What is the tonicity of maintenance fluids?
|
Hypotonic or isotonic
|
|
In some critically ill patients, addtional K is needed and is given in the form of what?
|
KCl
|
|
What is the most important monitoring device?
|
Human senses
|
|
According to the minimum monitoring standards of the ASA, what factors must be continually monitored during anesthesia?
|
-CNS, depth of anesthesia
-Oxygenation -Ventilation -Circulation -Temperature |
|
What parameters are monitored during induction?
|
-respiration
-heart rate -mm color -palpebral reflexes -muscle activity -swallowing and coughing -eye position |
|
What parameters and body systems are monitored while the animal is unconscious?
|
-CVS
-respiratory system -eye signs -muscle activity -body temp -swallowing -equipment |
|
What additional monitoring takes place during recovery?
|
Adequacy of pain control
|
|
Rotation of the eye occurs during which levels of anesthesia?
|
Light and medium
|
|
With dogs and cats the surgical plane of anesthesia is when the eye is in which position?
|
Ventromedial
|
|
Is the pupillary light reflex active during anesthesia?
|
Yes, but obtunded
|
|
Does mydriasis or miosis occur during GA?
|
Could be either depending on the technique
|
|
Why is a sterile opthalmic solution needed during GA?
|
Lacrimation slows dramatically
|
|
What happens to the palpebral reflex during GA?
|
It is lost with increasing depth of anesthesia
|
|
What eye signs are seen with Ketamine?
|
A brisk palpebral reflex and central eye position
|
|
Why is the corneal reflex rarely used?
|
Cornea is easily damaged
|
|
Why is it important that the swallowing reflex return before the ET tube is removed?
|
If the animal vomits they will swallow instead of aspirating
|
|
When is checking the pedal reflex helpful?
|
Gauging when intubation should be attempted
|
|
Which reflex can be tested on a cat for depth of anesthesia, but is not reliable?
|
Ear flick
|
|
Which muscles should be checked to assess depth of anesthesia?
|
Muscles of mastication, tone of jaw (ease of opening mouth), flex and extend the elbow, carpus..neck muscles in horses, swans, small ruminants)
|
|
When might you see muscle rigidity in anesthetized animals?
|
When Ketamine mixtures are used.
|
|
By which methods do we monitor the CVS during anesthesia?
|
-CRT and mm color
-palpation of peripheral pulse -esophageal stethoscope -ecg -arterial blood pressure -central venous pressure |
|
What is CRT and mm color an idication of?
|
Peripheral perfusion...not ABP
|
|
What do cyanotic blue mm indicate?
|
<5g oxygenated Hb per 100 ml blood
|
|
Sepsis or dehydration can be seen by what color of mm?
|
Brick red
|
|
What do ashen grey mm indicate?
|
Circulatory failure
|
|
What is the normal value for CRT?
|
< 2 seconds
|
|
When palpating a peripheral pulse during anesthesia, what should you consider?
|
Tone and amplitude, rhythm and synchronicity with the heart/ECG
|
|
What information about blood pressure can be gained by palpating the peripheral pulse?
|
None, reflects stroke volume not blood pressure
|
|
The femoral pulse is palpable at what pressure?
|
80 mm Hg
|
|
What can be identified and measured via an esophageal stethoscope?
|
Respiratory rate and heart rate
|
|
What information is gained by using an ECG?
|
Electrical activity of the heart- arrhythmias and the myocardial environment...no information on the mechanical function or cardiac output
|
|
How might the ECG be misleading?
|
Will be normal with hypovolemia
May be normal during cardiopulmonary arrest |
|
What is the definition of blood pressure?
|
BP = cardiac output x total peripheral resistance
|
|
During anesthesia, the goal for blood pressure is to maintain MAP at what level? SAP?
|
MAP > 60 mm Hg
SAP > 80 mm Hg |
|
What damage can result from hypotension?
|
Reduced perfusion of vital organs (kidney, brain, liver)
|
|
Urine output is an indirect indicator of cardiac output and blood pressure, at what pressure must the kidneys be perfused to produce urine?
|
MAP > 60mm Hg
|
|
What is the purpose of monitoring Centrsl Venous Pressure?
|
Assess right-sided heart function and adequacy of circulating blood volume
|
|
What is normal CVP?
|
2-5 cm H2O
|
|
What does an elevated CVP indicate?
|
Right ventricle is unable to deal with volume of blood returning to it
|
|
What are the likely causes of elevated CVP?
|
-decreased cardiac function
-fluid overload |
|
Low CVP (<1cm H2O) can be an indication of what condition?
|
Low circulating blood volume
|
|
Bradycardia and hypothermia are indications of anesthesia that is too light or too deep?
|
Too deep
|
|
Tachycardia can be an indication of what conditions during GA?
|
Light anesthesia
Pain |
|
Arrhythmias during GA can be caused by what?
|
-myocardial disease
-light anes. causing pain/symp stimulation -excessively deep anes -hypoxemia -respiratory acidosis -metabolic acidosis -electrolyte abnormalities -hypothermia |
|
How is respiratory monitoring accomplished during GA?
|
-rate
-depth/tidal volume -pattern -evaluation of giving a "sigh" -oxyhemaglobin saturation (pulse ox) -end tidal CO2 (capnograph) -blood gas analysis |
|
Name 3 methods that can used to detect the respiratory rate
|
-count chest or reservoir bag excursions
-listen w/ esophogeal stethoscope -use Apalert |
|
What are some causes of a slow respiratory rate or apnea?
|
-intubation
-excess anes depth -resp depressant drugs (opiods, barbs, iso) -hypocapnia -muscle relaxants -increased intracranial pressure |
|
What are some of the causes of rapid respiration during GA?
|
-light anes
-drug related (opioids can cause panting) -hypercarbia -hyperthermia |
|
Shallow respiration will likely have what effect on tidal volume?
|
Reduced
|
|
Describe a normal GA respiratory pattern.
|
Chest wall out on inspiration, abd wall quietly in on expiration
|
|
Ketamine can induce what type of breathing patter?
|
Apneustic
|
|
By what technique can the anesthetist check the respiratory system if the animal and check the anesthesia machine for leaks?
|
By giving a "sigh"...squeezing the reservoir bag with the pop-off valve closed
|
|
Why is it important to maintain homeothermy during anesthesia?
|
Essential for cardiac function, metabolism, normal enzyme activity and homeostasis during sugery
|
|
When is the greatest amount of heat lost, and why?
|
Within the first 20 mins of GA due to redistribution of heat from the core to the periphery.
|
|
Which animal will have the largest heat loss...a small or large dog?
|
Small dog....surface area:body weight ratio
|
|
What effect does hypothermia have on cardiac function?
|
Myocardial irritation and bradycardia, reduction in cardiac output and blood pressure
|
|
What effect does hypothermia have on MAC?
|
Reduction in MAC, more easily overdosed
|
|
How should core temp be monitored during GA?
|
By esophageal probe or tympanic membrane probe...rectal is for peripheral temp not core
|
|
What are some methods that can be used during surgery to maintain core body temp?
|
-avoid cold solutions
-minimize surgery time -ambient temp as warm as is comfortable for staff -warm anesth. gases -bair huggers (forced warm air) -thernal blankets -warm IV fluids |
|
Minimum CVS monitoring during GA includes what?
|
-heart rate
-rhythm -pulse -mm color -CRT |
|
What additional CVS monitoring is needed for high risk patients?
|
-ECG
-blood pressure +/- CVP |
|
What respiratory monitoring is needed during GA?
|
-rate
-depth -oxygenation |
|
What does pulse oximetry measure?
|
Oxyhemoglobin saturation of arterial (pulsating) blood
|
|
Oxyhemoglobin absorbs light more strongly at which wavelength?
|
940 nm
|
|
What are the best locations for placing a pulse ox probe?
|
Tongue, vulva, toe webbing, prepuce, ear
|
|
An "excellent" pulse ox reading would be what?
|
97-100 saturation
|
|
Pulse ox monitors oxyHb saturation, but does not measure what?
|
PaO2
|
|
What does a capnograph measure?
|
CO2 tension in both inspired and expired gases
|
|
End tidal CO2 is a good indication of CO2 where?
|
Alveolar...in turn a good indication of arterial CO2 tension
|
|
What key components should you examine on a capnogram?
|
-height of plateau and see if it returns to zero
-shape and regularity of peaks and troughs |
|
Describe a normal capnogram.
|
-smooth upstroke
-horizontal smooth plateau -a teep down stroke -baseline with zero CO2 tension |
|
On a capnogram, what does a slanted upstroke indicate?
|
Slow exahlation- respiratory obstruction, tube obstruction, obstructive airway disease
|
|
On a capnogram, what does an increasecd or decreased plateau height mean?
|
Hyperventilation or hypoventilation or low cardiac output
|
|
On a capnogram, what does a slanted downstroke indicate?
|
Slow inspiration- insufficiently inflated ET tube cuff, malfunction of inspiratory vavle on rebreathing system, bronchoconstriction
|
|
What does a base above zero indicate on a capnogram?
|
Rebreathing Co2- exhausted soda lime or insufficient fresh gas flow
|
|
What can be the cause of a sudden loss of tracing of a capnogram?
|
ET tube disconnection, cardiac arrest
|
|
Name thr 2 types of capnographs that are available.
|
Maintream
Side stream |
|
What is the advantage of a mainstream designed capnograph?
|
Very fast response
|
|
What is a disadvantage of a sidestream designed capnograph?
|
Lag time in display
|
|
Give 3 condition that decrease end-tidal CO2 volume.
|
-hyperventilation
-low cardiac output -low CO2 production (hypothermia) -pulmonary embolism (incr. alveolar dead space) -sampling error (leak) |
|
Give 3 conditions that can increase end tidal CO2 levels.
|
-hypoventilation
-rebreathing -sepsis -hyperthermia -skeletal muscle activity -malignant hyperthermia |
|
In addtion to blood pressure measurement, what other measurement will help evaluate cardiac output?
|
Arterial blood pressure
|
|
Mean arterial blood pressure (MAP) should be maintained at what level?
|
> 70mm Hg
|
|
Systolic arterial pressure (SAP) should be maintained at what level?
|
> 90 mm Hg
|
|
Blood flow it major organs is autoregulated. This function could be compromised if blood pressure falls below what range?
|
60 -120 mm Hg
|
|
During anesthesia, blood pressure that falls below 80/40 mean what?
|
Possible organ dysfunction..intervention needed
|
|
What should normal Systolic and Diastolic pressure be?
|
Systolic 90-120 mm Hg
Diastolic 55-70 mm Hg Mean 60-100 mm Hg |
|
Hypotension is defined as MAP at what level?
|
MAP < 70 mm Hg
(systolic < 90 mm Hg) |
|
Hypertertension is defined as MAP at what level?
|
MAP > 100 mm Hg
(systolic > 150 mm Hg) |
|
If a femoral pulse and a metatarsal both can both be palpated, blood pressure can be assumed to be a what level?
|
> 80 mm Hg
|
|
What if just the femoral pulse is present but not the metatarsal?
|
Systolic pressure is 80 mm Hg = hypotension
|
|
For the kidneys to produce urine, they must be adequately perfused. MAP must be what for this to occur?
|
> 60 mm Hg
|
|
What is the "gold standard" method for monitoring arterial blood pressure?
|
By placing a catheter in a peripheral artery ( dorsal metatarsal in a dog, femoral artery in a cat)
|
|
What is DINAMAP?
|
Device for Indirect Non-invasive Automated Mean Arterial Pressure
|
|
By what other method can arterial blood pressure be monitored?
|
Doppler ultrasound
|
|
Does Doppler measure systolic or diastolic pressure?
|
Systolic
|
|
What is meant be Central Venous Pressure (CVP)?
|
Measure of the hydrostatic pressure in the right atrium
|
|
How is CVP determined?
|
By the function of the right heart and pressure in the venous blood of the vena cava
|
|
True or False. CVP measures cardiac function and blood volume.
|
False...does not measure either directly...must be interpreted
|
|
CVP measurement can provide ealy evidence of what conditions?
|
-volume overload
-recurrent pericardial effusion -right side heart failure |
|
Low CVP is indicative of what condition?
|
Low CO = hypovolemia
|
|
High CVP is indicative of what?
|
low CO = heart failure
|
|
CVP monitoring is considered mandatory under what circumstance?
|
In patients where concern exists regarding fluid therapy
|
|
What is the normal range for CVP?
|
0 - 5 cm H2O
|
|
Values > 12-15 cm H2O are suggestive of what condition?
|
Volume overload
< 0 = hypovolemia |
|
Is CVP lowest or highest during expiration?
|
Highest
|
|
How can CVP be estimated?
|
By looking at jugular filling pressure- with volume overload jugular may look distended, pulsations may be visible
|
|
What is the difference between pain and nociception?
|
Pain is a conscious experience
Nociception describes the process of neurotransmission |
|
Acute and persistent pan can have what overall effects on the patient?
|
-metabolic effects (can affect wound healing)
-cardiovascular effects (hypertension, tachycardia) -poor recovery from anesthesia, greater risk of post-op complication -chronic pain with increased risk to auto mutilation, wound biting |
|
Define the nociceptive C fibers.
|
Slow and unmyelinated
|
|
Define the nociceptive A alpha fibers.
|
Small diameter myelinated fibers
|
|
The nociceptive fibers conduct a noxious stimulus to where in the spinal cord?
|
Dorsal horn
|
|
Define Hyperalgesia
|
An exaggerated response to a noxious stimulus
|
|
What is allodynia?
|
A pain response to a non-noxious stimulus (such as a gentle touch)
|
|
How do peripheral nociceptors ( C and A) become sensitized?
|
Induced by inflammatory mediators released by tissue damage
|
|
By what 3 ways can we assess pain?
|
-physiological signs
-behavioral signs -response to analgesia |
|
What are some of the physiological signs of pain?
|
-altered heart rate
-altered respiratory rate -hypertension -increased temp -changes in biochemical factors (cortisol, adrenaline, noradren, acute phase proteins) |
|
In the dog and cat, what are some behavioural indications of pain?
|
-postures (hunching, praying)
-locomotion (stiff, non-weight bearing) -vocalization -facial expression -attention to the affected area -hyperalgesia, allodynia |
|
What is the response of a horse to any stimulus which frightens or hurts it?
|
Attempt to escape
|
|
What is a sign of persistant pain in a horse?
|
Withdrawal, weight shifting, restlessness, subtle changes in head and ear posture
|
|
How do ruminants respond to pain?
|
Withdraw, grind teeth, weight shifting, restlessness, depression
|
|
What is the best tool available to assess acute pain in animals?
|
Short form of the Glasgow Pain Assessment System
|
|
What are the 4 main categories of analgesia?
|
-pre-emptive
-multimodal -regional/local -analgesic infusions |
|
What is the theory behind pre-emptive analgesia?
|
Central sensitization is more susceptible to analgesic agents before rather than after a noxious stimulus
|
|
In dogs and cats, why must you be cautious is using NSAIDs as pre-emptive analgesics?
|
Risk of renal impairment
|
|
Which analgesics can be given intra-operatively via CRI?
|
-opioids
-ketamine -lidocaine |
|
Which analgesic groups are usually given post op?
|
Opioids plus NSAID's
|
|
Sedation drugs should always be given in combination with what other type of drug?
|
An analgesic
|
|
What level of analgesia is provided by anesthetic agents?
|
None
|
|
By which routes can analgesic drugs be administered?
|
Local
Intrathoracic Intraperitoneal Intra-synovial Systemic- bolus or infusion Extradural Oral |
|
What is the theory of multimodal analgesia?
|
Use a combination of various agents by various routes in smaller doses to produce an overall greater effect than using a single large dose of one agent
|
|
What is the method of action of NSAID’s?
|
Prevent the formation of eicosanoids from arachidonic acid by blocking the cyclo-oxygenase enzyme
|
|
In vet med, which NSAID is selective for COX-2?
|
Firecoxib
|
|
What is the most common side effect of oral NSAID therapy?
|
GI ulceration
|
|
What is the potential effect of NSAID therapy on the kidneys?
|
Nephrotoxicity-impairs PGE2 production
|
|
What effect can NSAIDs have on platelets?
|
Can interfere with platelet aggregation- predisposing to bleeding disorders
|
|
Are NSAIDs high or low plasma protein bound?
|
Highly protein bound
|
|
What are the contraindications for the use of NSAIDs?
|
-concurrent corticosteroid medication
-hypotension or hypovolemia -gastric ulceration or vomiting -renal dysfunction -coagulopathy |
|
What change in the dosing of NSAIDs must you make when treating a cat?
|
Carefully dosed at longer intervals (deficient in glucoronidation enzymes)
|
|
What class of drugs are the most effective analgesic agents?
|
Opioids
|
|
Name the 3 types of opioid receptors?
|
Mu, delta, kappa (3,1,2)
|
|
What effect do opioids have on the CVS?
|
Benign effects
|
|
What effect does giving opioids have on other anesthetic drugs?
|
Anesthetic-sparing
|
|
Are opioids reversible?
|
Yes
|
|
What side effect can opioids have on respiration?
|
Respiratory depression
|
|
What side effect might be seen if an opioid is used as a pre-med in a non-painful animal?
|
Nausea/vomiting
|
|
What effect do opioids have on the GIT?
|
Reduced motility
|
|
What is the difference between a partial and a full opioid agonist?
|
Full agonist is dose dependent and the effect can be enhanced by incremental dosing
Partial agonist cannot induce a maximal effect |
|
Which opioids are best suited for severe pain control?
|
Morphine, methadone, fentanyl
|
|
Is Butorphanol a good analgesic?
|
No…is a good sedative and anti-tussive
|
|
What is the duration of action of Morphine in dogs? Cats?
|
Dog: 3-4 hours
Cat: 6-8 hours |
|
What might occur if Morphine is given too quickly IV?
|
Histamine release, anaphylaxis
|
|
What is the typical dose for Morphine in a dog?
|
0.3-0.5 mg/kg
|
|
Methadone is a full mu-selective agonist. What is its duration of action?
|
4-6 hours
|
|
Fentanyl is a very potent analgesic. What effects can be induce by using fentanyl?
|
Bradycardia, respiratory depression
|
|
What drug is an opioid antagonist?
|
Naloxone
|
|
Burpenorphine is what type of opioid?
|
Partial agonist
|
|
Burpenorphine is used under what conditions?
|
Visceral or soft tissue pain, esp in cats
|
|
Aside from IM or IV dosing, what other route can Buprenorphine be given?
|
Orally, well absorbed by the mucosa
|
|
How should the skin surface be prepared for the placement of a Fentanyl patch?
|
Clipped, wiped clean…no soap or alcohol
|
|
What are the disadvantages to using a Fentynal patch?
|
-analgesic response is highly variable
-lag time until effective plasma concentration is reached -potent drug- open to accidental or deliberate use |
|
Opioids produce what effect on cats’ eyes?
|
Mydriasis
|
|
Ketamine is an antagonist of which receptor type?
|
NMDA
|
|
When should Ketamine be used as an analgesic?
|
In patient’s whose pain has not been controlled by standard analgesic regimes based on opiods and NSAIDs (spinal surgery, amputation)
|
|
Which A2 agonist has been recognized as possessing analgesic properties?
|
Medetomidine
|
|
Tramadol has morphine-like effect on which receptors?
|
All opioid receptors, esp Op3
|
|
How does Tramadol produce an analgesic effect?
|
Inhibition of serotonin and noradrenaline re-uptake
|
|
What are the most common side effects to using Tramadol?
|
Mild nausea and vomiting
|
|
As an analgesic, Gabapentin is used in what cases?
|
Neuropathic pain
|
|
What drug has NMDA antagonist effects and can be used to lower the dose of opioids needed?
|
Amantidine
|
|
What role do sedative drugs play in analgesia?
|
Anxiolytic
|
|
What drugs are contained in MLK?
|
Morphine, Lidocaine, Ketamine
|
|
When using MLK with isoflurane, how much should the MAC be reduced?
|
By 45%
|
|
Why isn’t MLK given to cats?
|
Due to the Lidocaine
|
|
What other drug can be used instead of Mophine to make MLK?
|
Fentanyl (FLK)
|
|
What is TIVA?
|
Total intravenous anesthesia..when IV is used for induction and maintenance of anesthesia
|
|
In an IV solution, 1% is hoe many grams in 100 ml?
|
1 gram
|
|
How much is Ketamine 100 mgmgl?
|
10%
|
|
5% Thiopental is how many mgml?
|
50 mgml
|
|
Thiopental 25 mgml is what percent?
|
2.5%
|
|
Which class of drug is the oldest injectable anesthetic?
|
Barbituates
|
|
Which barbituate is on of the few available today in vet med?
|
Thiopental
|
|
In solution, thiopental is highly alkaline, what effect does this have on tissues?
|
Highky irritant if extravasated
|
|
What is the mechanism of action of barbituates?
|
Depresses the RAS in the brainstem responsible for wakefulness, interacts with GABA
|
|
Which is the active portion of a barituate...the protein bound or unbound?
|
The unbound is active
|
|
Thiopental is up to 40% unionized in plasma, making it lipid soluable. In this form, what can the drug do?
|
Cross the blood brain barrier
|
|
What biochemical condition will increase the intensity of the barbituate effect?
|
Acidosis
|
|
Is recovery from a drug due to metabolism or redistribution?
|
Redistribution
|
|
In which breeds should Thiopental be avoided?
|
Sight hounds (low body fat = lack of depot for the drug)
|
|
How quickly does Thiopental take effect?
|
One arm-brain time...unconsciousness in 30 seconds
|
|
What effect does Thiopental have on intracranial pressure?
|
Lowers it
|
|
What level of analgesia does Thiopental produce?
|
None
|
|
What are the CVS effects of Thiopental?
|
Cardiovascular depression, vasodilation, drop in output. arrhythmogenic
|
|
What respiratory effect is usually seen post induction?
|
Apnea
|
|
What caution must be taken with preparing Propofol?
|
Contains no preservative, can grow bacterial
|
|
What is the mechanism of action of Propofol?
|
Enhances GABA activity, enhances NMDA activity
|
|
What effect does Propofol have on intraocular pressure?
|
Reduces it
|
|
What are Propofol shakes?
|
Some animals can develop muscle rigidity and spasm following induction. responds to Ketamine
|
|
Does Propofol raise the seizure threshold?
|
No, used as an anti-convulsant in dogs with refractory epilepsy
|
|
What are the CVS effects of Propofol?
|
CVS depression, vasodilation, decreased aterial blood pressure, stroke volume and cardiac output
Little effect on heart rate |
|
What are the respiratory effects with Propofol?
|
Respiratory depression
|
|
How can the pain of injecting Propofol be reduced?
|
Draw blood back into the syringe prior to injection, use a low dose of lidocaine
|
|
Do pigs require higher or lower doses of Propofol?
|
Higher
|
|
What caution should be taken when using Propofol in cats?
|
Prolonged recovery if used as CRI
|
|
Which neuroreactive anesthetic agent is not yet licensed in the US?
|
Alfaxalone
|
|
What is the mechanism of action of Alfaxalone?
|
Enhances inhibitory effects of GABA, acts on central glycine and nicotinic Ach receptors
|
|
Alfaxalone has CVS effecst similar to what agent?
|
Propofol
|
|
In which species is Alfaxan not used?
|
Dogs, histamine release
|
|
Name the 2 common dissociative drugs used in vet med
|
Ketamine, Tiletamine
|
|
Ketamine is usually co-administered with what other class of drugs?
|
Rarely given alone, usually given with BZ, ACP, A2 agonist
|
|
What is the mechanism of action of Ketamine?
|
Unclear. Believed to be a result from inhibition of excitatory neurotransmitters
|
|
What is the name of the Ketamine metabolite formed in the liver?
|
Nor-ketamine
|
|
What is a disadvantage of Ketamine in terms of recovery?
|
Usually an unpleasant recovery
|
|
What are the CNS affects of Ketamine?
|
-increased cerebral blood flow
-increased cerebral O2 consumption -increased intracranial pressure -epileptogenic -good analgesic -increases muscle tone |
|
What ocular effects are seen with Ketamine?
|
-eyelids remain open (use eye gel)
-increases intra-ocular pressure -dilated, centrally fixed pupils |
|
What effect does Ketamine have on the CVS?
|
Stimulates the CVS, indirect sympathomimetic action
|
|
What are the respiratory effects of Ketamine?
|
Minimal respiratory depression
Pharyngeal/laryngeal reflexes maintained Apneustic breathing Hypersalivation |
|
What are some conditions that contra-indicate the use of Ketamine?
|
-increased ICP
-hepatic, renal disease w/ obstruction -risk of seizure -increased intra-ocular pressure |
|
How does Tiletamine compare to Ketamine?
|
Similar in action, but more potent and a longer duration of action
|
|
What are the common uses for Tiletamine?
|
-aggressive dogs, feral cats
-horses, pigs, exotics |
|
Whjat is the advantage of using Etomidate?
|
Has minimal CVS depressant effects, minimal effects on the sympathetic nervous system and barorecptors
|
|
What is the effect of Etomidate on the adrenals?
|
Temporary adrenal suppression
|
|
What is TIVA?
|
Using drugs in combination as a continuous IV infusion to maintain anesthesia when an inhalational agent is not desirable or possible
|
|
What are the properties of the ideal drugs for TIVA?
|
-non cumulative
-rapidly metabolized -non irritant -no undersirable properties from long administration |
|
What is an example TIVA technique used in equine medicine?
|
Triple drip...Guaphenesin, ketamine and xylazine
|
