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45 Cards in this Set

  • Front
  • Back

Adjunct

a drug that is not a true anesthetic but that is used during anesthesia to produce other desired effects such as sedation, muscle relaxation, analgesia, reversal, neuromuscular blockade, or parasympathetic blockade

agonist-antagonist

a drug that binds to more than one receptor type, simultaneously stimulating at least one and blocking at least one

agonist

a drug that binds to and stimulates tissue receptors

analeptic agent

a drub that causes general central nervous system stimulation

anesthetic agent

any drug used to induce a loss of sensation with or without unconsciousness

antagonist

a drug that binds to but does not stimulate receptors

anticholinergic

an adjunct that lessens parasympathetic effects by blocking muscarinic receptors of the parasympathetic nervous system, also known as a parasympatholytic

apnea

a temporary absence of spontaneous breathing

apneustic respiration

a breathing pattern, most often seen during dissociative anesthesia, in which there is a pause for several seconds at the end of the inspiratory phase, followed by a short, quick expiratory phase

ataxia

inability to coordinate movement

bagging

inflating the patient's lungs by squeezing the reservoir bag. Manual positive-pressure ventilation

cataleptoid state

a state produced by dissociative agents, in which a patient does not respond to external stimuli and has a variable degree of muscle rigidity

colic

severe abdominal pain of sudden onset caused by a variety of conditions including obstruction, twisting, or spasm of the intestinal tract

cortisol

a natural steroid hormone, secreted by the adrenal cortex, which plays a role in protein, carbohydrate, and fat metabolism

dead space

the breathing passages and tubes that convey fresh oxygen from the source to the alveoli, but in which no gas exchange occurs

dysphoria

anxiety, uneasiness, and restlessness most often produced by opioids, the opposite of euphoria

enantiomers

a mixture of two molecules that are mirror images of one another. the dextrorotatory enantiomer is a molecule that rotates the plane of polarized light to the right an the levorotatory molecule rotates it to the left

fasciculations

involuntary muscle twitching

hypoventilation

slow and/or shallow ventilation, resulting in decreased minute volume

mydriasis

dilation of the pupil of the eye

neuromuscular blockers

an adjunct used to relax or paralyze skeletal muscles as a part of balanced anesthesia

nystagmus

a rhythmic, involuntary oscillation of both eyes

partial agonists

a drug that binds to and partially stimulates tissue receptors

pharmacodynamics

the effect that a drug has on the body, the drug action

preanesthetic medications

an anesthetic agent or adjunct administered during the preanesthetic period to provide one or more of a variety of desired effects, including analgesia, sedation, and muscle relaxation

reversal agents

a drug used to lessen or abolish the effects of anesthetic agents or adjuncts, and which is therefore used to wake the patient after sedation or anesthesia

somatic analgesia

absence of pain of the skin, muscle, bone, and connective tissue

status epilepticus

continuous seizures, or a series of seizures in rapid succession

tachycardia

rapid heart rate

tidal volume

the volume of a normal breath, approximately 10-15mL/kg body weight

visceral analgesia

absence of pain in the internal organs

Chapter 3 notes

-local anesthetics produce a loss of sensation in a localized area of the body


-general anesthetics induce a loss of sensation over the entire body, accompanied by unconsciousness.


-neuromuscular blockers are generally used for relax or paralyze skeletal muscles during ophthalmic, or orthopedic surgeries


-antagonists competitively bind to receptors and displace the corresponding agonist, blocking further action


-anesthetic agents cause unconsciousness and indirectly provide analgesia because the patient can not feel pain when unconscious, but they are not true analgesics


-most anesthetic agents with the exception of diazepam are water soluble, in general two or more water soluble drugs can be mixed safely.


-diazepam and ketamine are the only non-water soluble and water soluble drugs that can be mixed in the same syringe


-anticholinergics, tranquilizers and sedatives (phenothiazines, benzodiazepines, and alph2-agonists) and opioids are used as preanesthetics


-Premeds are used to:


1. calm or sedate an excited, frightened, or vicious animal, reduces anxiety and simplifies patient restraint


2. minimize adverse effects of concurrently administered drugs. (ketamine causes excessive salivation in some patients and alpha2-agonists may cause profound bradycardia or heart block, anticholinergics are given to decrease the exaggerated parasympathetic effects)


3. reduce required doses of concurrently administered agents (premeds often decreases the amount of general anesthetic required to produce surgical anesthesia)


4. produce smoother anesthetic inductions and recoveries


5. decrease pain and discomfort before, during, and after surgery


6. produce muscle relaxation


-phenothiazines have antiemetic properties


-many opioids are effective cough suppressants


-IV doses of premeds are generally one half the SQ or IM dose.


PREMEDS:


-Anticholinergics:


1. also known as parasympatholytics


2. commonly used to prevent and treat bradycardia and to decrease salivary secretions arising fro parasympathetic stimulation


3. atropine and glycopyrrolate are commonly used


4. atropine is derived from the nightshade plant


5. glycopyrrolate is a synthetic quarternary ammonium compound


6. Acetylcholine is the primary neurotransmitter in the PNS responsible for parasympathetic (cholinergic) effects.


7. nicotinic and muscarinic receptors are the PNS receptors for acetylcholine


8. nicotinic receptors are located on the postganglionic neurons at the junction with the preganglionic neurons


9. muscarinic receptors are located on the target organs


10. anticholinergics competitively block binding of acetycholine at the muscarinic receptors


11. the vagus nerve (10th cranial nerve) innervates numerous organs (heart, lungs, GI tract, some secretory glands, and the iris) and may be stimulated by endotracheal intubation, traction on visceral organs (viscerovagal reflex), manipulation of the eye (oculovagal reflex), and by some drugs (alpha2-agonists, apioids, and common general anesthetics), increased binding of acetycholine to muscarinic receptors caused by vagal stimulation produces observable parasympathetic effects (bradycardia, bronchoconstriction, excess tear and saliva production, increase gi motility and miosis).


12. atropine: onset of action about 5 min after IM injection, reaches peak effect in 10-20 minutes, and has a duration of 60-90 minutes, onset of action is about 1 minute after IV injection and peak effect 3-4 minutes


13. glycopyrrolate: onset of action about 5 minutes, reaches peak effect in about 30-45 minutes, and has a duration of 2-3 hours, salivary secretions can be suppressed for up to 7 hours. Does not cross blood brain barrier


14. cause mydriasis and depressed PLRs


15. reduce lacrimal secretions


16. cause bronchodilation which increases anatomic dead space


17. may induce temporary first or second degree heart block, followed by sinus tachycardia


18. should be avoided in animals who have preexisting rapid heart rates (more than 140 bpm dogs, 180 bpm cats, 60 bpm horses, and 100 bpm ruminants) or heart disease


19. associated with thickening of respiratory and salivary secretions in cats and ruminants


20. inhibits intestinal peristalsis which and lead to colic in horses and bloat in ruminants


-Tranquilizers and sedatives


1. a tranquilizer reduces anxiety but does not necessarily decrease awareness and wakefulness


2. a sedative causes reduced mental activity and sleepiness


3. three classes typically used: phenothiazines, benzodiazepines, and alpha2-agonists


4. phenothiazines protect against cardiac arrhythmias and are antiemetics


5. alpha2-agonists are analgesics and can produce vomiting


6. alpha2-agoinsts and phenothiazines are good muscle relaxers


7. sedatives relax the tissues in the pharynx which may cause respiratory distress in brachiocephalic dogs especially those who exhibit significant respiratory stridor when awake.


8. sedated animals may exhibit unusual behavior such as aggression or may suddenly become aroused.


9. Phenothiazines (ace)


--depress the reticular activating center of the brain and block alpha-adrenergic, dopamine, and histamine receptors


--metabolized by the liver


--crosses placental barrier slowly


--onset of action 15min after IM injection in dogs and IV injection in horses


--peak effect occurs within 30-60minutes


--duration of action is 4-8hours in small animals, may be longer (up to 48 hours) if higher doses are used or if given to old, sick, or debilitated patients or patients with liver disease, 1-3 hours in horses


--causes calmness, sedation, reluctance to move, and decreased interest in the patient's surroundings.


--sedation is less pronounced in cats and is less pronounced than with alpha2-agonists


--does not control pain, but decreases anxiety to patients in pain receiving analgesics


--causes peripheral vasodilation, hypotension, reflexive increase in heart rate, and increased heat loss


--directly decreases cardiac output


--protect against ventricular arrhythmias


--worsens depressive effects of other sedative and anesthetic agents


--antiemetic


--prevents release of antihistamines decreasing allergic reactions, should not be used in patients undergoing allergy testing


--reduces seizure threshold


--may occasionally produce excitement or aggression rather than sedation and may persist in the postanesthetic period but should resolve after 48 hours


--severe hypotension, dose dependent and more pronounced in frightened or excited patients, up to a 20-30% drop in blood pressure when on isoflurane


--causes penile prolapse in horses and other large animals


--decreased PCV, occurs within 30 minutes of administration in dogs and horses likely due to uptake of RBCs by the spleen


--manufacturer's dose recommendations are higher than actually needed. Recommended dose is 0.05-0.1mg/kg in small animals with a max dose of 3mg in dogs and 1mg in cats and 0.03-0.05mg/kg in horses, higher doses will increase hypotension but not sedation.


10. Benzodiazepines:


--muscle relaxant, anticonvulsant, and appetite stimulating properties


--may produce dysphoria, excitement, and ataxia in healthy, young dogs, cats, and horses


-- diazepam is irritating and poorly absorbed when given IM


-- depress the CNS by increasing affect of endogenous gamma-aminobutyric acid (GABA), an inhibitory neurotransmitter in the brain


--diazepam is not water soluble


--midazolam and zolazepam are water soluble


--onset of action about 15 minutes after IM injection and last 1-4 hours


--have an antianxiety and calming effect


--do not cause sedation unless given with ketamine or opioids


--diazepam enhances the sedation and analgesia of other agents


-- no analgesic effect and when used alone will not calm animals in pain


--minimally affect heart rate, blood pressure, and cardiac output


-- relax skeletal muscles


-- appetite stimulant in cats and ruminants


-- cross the placental barrier and may cause CNS depression in neonates delivered by csection


--giving diazepam rapidly IV can cause pain, bradycardia, hypotension, and apnea.


--diazepam is very soluble in plastic and overtime may be absorbed by syringes, iV bags, and Iv lines


--flumazenil reverses the effects


11. Alpha2-agonists


--xylazine, dexmedetomidine, detomidine, and romifidine


--SQ administration is less reliable


--work on alpha2-adrenergic receptors of the sympathetic nervous system within the CNS and peripherally causing a decrease in norepinephrine a neurotransmitter


--SNS has alpha, beta, and dopaminergic receptors.


--Stimulation of the SNS is associated with the fight or flight response


--stimulation of alpha2 receptors causes sedation, analgesia, bradycardia, hypotension, and hypothermia


--metabolized by the liver and excreted by the kidneys


--adequate renal and hepatic function are necessary


--sedation occurs within 5-15 minutes after IV injection or 15-30 minutes after IM injection and lasts about 1-2 hours, complete recovery takes about 2-4 hours if drug is not reversed


--horses: lowered head, relaxed facial muscles, and drooping lower lip


-- sedation is dose dependent


-- provide analgesia, but may be short lived


-- after injection there is a dose dependent vasoconstriction resulting in a brief period of hypertension and reflex bradycardia during which the MM may look pale, may produce cardiac arrhythmias, followed by decreased cardiac output, hypotension, and further drop in heart rate due to decreased sympathetic tone


-- depress the respiratory system


-- muscle relaxation


-- creased effects of other anesthetics (50% decrease of propofol and inhalant agents)


-- may cause vomiting shortly after administration


-- can cause hyperglycemia because secretion of insulin by the pancreas is reduced


-- can cause hypothermia due to decreased thermoregulation and shivering


-- may cause temporary behavior changes


-- cause profound cardiovascular depression and should not be used in patients with compromised cardiovascular systems


--should not be administered to patient's showing respiratory disease


-- may increase urination because they interfere with the release of antidiuretic hormone


-- xylazine causes increased intrauterine pressure in cattle and may lead to abortion in the last trimester


-- horse may sweat


-- can be absorbed through skin abrasions and MM and as little as 0.1ml of dexdomitor can cause hypotension and sedation in humans


12. Alpha2 - antagonists:


--yohimbine, tolazoline, and atipamezole reverse the effects of alpha2 -agonists


--yohimbine and tolazoline are used to reverse the effects of xylazine


--atipamezole is used to reverse dexdomitor


--displace the agonist from the alpha2 receptor


--doses are bsed on the amount of agonist that was given and the length of time since agonist administration and should be reduced if more than 30 minutes have elapsed


--adverse effects include excitement, muscle tremors, hypotension, tachycardia, salivation, and diarrhea


--should not be given when anticholinergics have been given


-Opioids


1.used for analgesia, sedation, anesthetic induction when used with other agents


2. classified as agonists, partial agonists, agonist-antagonist, or antagonists


3. morphine, hydromorphone, oxymorphone, fentanyl and meperidine (commonly used agonists)


4. buprenorphine (commonly used partial agonist)


5. butorphanol and nalbuphine (commonly used agonist-antagonist)


6. naloxone (commonly used antagonist)


7. three major opioid receptors: mu, kappa, and delta


8. agonists exert their effects by binding to and stimulating mu and kappa receptors, best drugs for moderate to severe pain


9. partial agonists only partially stimulate the receptors


10. agonist-antagonists stimulate the kappa receptors


11. antagonists (reversal agents) bind to but do not stimulate mu and kappa receptors


12. duration of action 1/2 to 3 hours, except for buprenex which lasts 6-8 hours and morphine which lasts 6-8 hours in horses.


13. opioid agents may cause CNS depression or excitement depending on the dose, route, agent used, species, patient temperament and pain status


14. predominant effect in dogs is sedation within 60 seconds of IV administration and 15 minutes of IM administration


15. cats, horses, dogs who are not in pain, and ruminants exhibit CNS stimulation which is more pronounced with pure agonists, particularly if given IV and with no other tranquilizer


16. cause bradycardia, especially if given with other drugs that cause bradycardia


17. cause miosis in dogs and mydriasis in cats, ruminants and horses


18. dogs become hypothermic, cats become hyperthermic


19. have a direct effect on the thermoregulatory center in the brain of dogs which mistakenly interprets normal body temperature as being elevated and causes the dog to pant


20. increased responsiveness to noise


21. sweating in horses


22. decreased urine production and urine retention


23. can cause salivation and vomiting. Initially, diarrhea and flatulence due to increased peristaltic movement, then GI stasis resulting in constipation.


24. should not be given to patients in which vomiting would be detrimental


25. morphine and meperidine can cause facial swelling and hypotension after rapid IV administration because of histamine release.


26. should be used with caution in cases of head trauma or other CNS disorders because of tendency to increase intracranial and intraocular pressure due to depressing ventilation


27. opioids commonly used for neuroleptanalgesia: morphine, buprenorphine, butorphanol, and hydromorphone


28. tranquilizers commonly used for neuroleptanalgesia: ace, diazepam, midazolam, xylazine, and dexmedetomidine


29. respiratory depression caused by buprenorphine may be unresponsive to naloxone because it tightly bind to mu receptors and is not easily displaced


30. naloxone acts within 2minutes of IV injection and 5 minutes of IM injection. Effects last 3-060minutes


31. In cases where the duration of action of the opiate is longer than that of naloxone, further doses may need to be given if renarcotization occurs.


INJECTABLE ANESTHETICS:


-ability to produce unconsciousness when given alone


-they do not provide analgesia and muscle relaxation, but can be used with other agents to produce these effects


-include propofol, barbiturates, and etomidate


-propofol is not used in large animals due to the cost


-given IV to effect


-Barbiturates:


1. all barbiturates act on the neurons in a similar manner to the inhibitory neurotransmitter GABA, they depress nerve impulses in the cerebral cortex resulting in CNS depression and a loss of consciousness, effect is terminated once drug leaves the brain and is metabolized, excreted, or redistributed


2. all barbiturates exist in ionized and nonionized forms, only the nonionized molecules can pass through cell membranes


3. when blood pH is normal (7.4) barbiturates penetrate to the expected extent and consequently have the expected effects, when blood pH is lower (acidosis) more of the drug is nonionized causing increased diffusion into the brain, meaning less drug is needed


4. travel in the blood attached to proteins and freely circulate, only those that are free pass into the brain to induce anesthesia, in hypoproteinemic animals more barbiturate is active so normal doses for healthy animals and may cause prolonged unconsciousness or death


5. cause full range of CNS depression, from mild sedation and hypnosis to complete unconsciousness


6. cause a dose dependent decrease in cardiac output and blood pressure, may be profound in patients that are already anesthetized


7. thiopental stimulates the PNS and the SNS causing autonomic imbalances, it increases the heart's sensitivity to epinephrine in excited or stressed patients and can lead to cardiac arrhythmias (VPCs, tachycardia or bradycardia, and AV heart block


8. cause the respiratory center to become relatively insensitive to increased CO2 levels


9. induction is often accompanied by sneezing, coughing and laryngospasm due to increased salivation


10. bigeminy - each normal heart beat is followed by a single VPC is common after induction


11. respiratory depression is related to dose and speed of administration


12. neonates are more sensitive to the effects on the respiratory system than the mother


13. sighthounds, critically ill animals, and hypoproteinemic and acidotic animals are particularly sensitive


14. low fat content of thin animals causes the fat stores to become saturated causing levels in the brain to remain high, prolonging the effects of the drug. thiopental is not recommended


15. perivascular injection of concentrations greater than 2.5% is toxic to capillary muscle and can cause thrombophlebitis and tissue sloughing, if it is injected perivascularly the area should be immediately infiltrated with saline in a volume equal to what was given to dilute and reduce the irritation, lidocaine without epinephrine can be mixed with the saline to cause vasodilation, absorption, and neutralization


16. may cause excitement during recovery, especially pentobarbital, premeds can reduce the incidence and diazepam may be administered to relieve the effects


17. enhance the neuromuscular blocking effect of muscle relaxants


18. phenobarb given daily increases the activity of some hepatic enzymes leading to more rapid clearance of the drug and shorter duration of activity of drugs metabolized by the liver


19. chloramphenicol may increase the effects of pentobarbital and phenobarb


20. Thiopental


--ultra short acting used for anesthetic induction


--onset of action is 30-60 seconds


--duration of anesthesia 10-15 minutes


--complete recovery usually in 1-2 hours


--once reconstituted has a shelf life of 1 week refrigerated and 3 days room temperature


--can reconstitute with sterile water, normal saline, or 5% dextrose to make a 2% or 2.5% (small animal) or 5% (large animal) solution


--do not inject air into the prepared solution it can cause precipitate formation


--always given to effect


--repeated administration is cumulative and recovery can be prolonged


--can be mixed with propofol and given in the same syringe


--lidocaine can be given first followed by thiopental to reduce the incidence of arrythmias


--can also be given after diazepam or midazolam


21. Methohexital


--ultra short acting


--onset of action 15-60 seconds


--duration of anesthesia 5-10 minutes


--once reconstituted shelf life is 6 weeks when reconstituted with sterile water


--a 1% - 2.5% solution is made for small animals


--one-third to one-half the calculated dose is given IV over 10 seconds to premeded patients


--repeated administration is not communulative


--may be given to sight hounds


--can cause profound respiratory depression


--lethal dose is only 2-3 times that of the anesthetic dose


--associated with excitement and seizures if given too slowly during induction and recovery


-- should not use in animals with preexisting CNS disease, including epilepsy


22. pentobarbital


--short acting


--given intraperitoneal to induce anesthesia in rodents


--respiratory depressant, difficult to control anesthetic depth, rough induction and recoveries


--narrow margin of safety, euthanasia does is almost twice the anesthesia dose


--when treating status epilepticus should be given to effect until seizures stop, should be given very slowly in small doses waiting several minutes before giving more


--onset of action 30-60 seconds


--if pedal reflex is lost the patient will likely require intubation and respiratory support


--initially will appear unable to raise head, the haw and tongue become relaxed as more is given with pedal reflex still present


--lasts 30minutes to 2 hours



-Propofol


1. ultra short acting nonbarbiturate


2. wide margin of safety


3. appears to affect GABA receptors


4. highly fat soluble


5. onset of action 30-60 seconds


6. duration of action 5-10 minutes


7. complete recovery in 20 minutes (dogs) and 30 minutes (cats)


8. produced dose dependant cns depression


9. not an analgesic


10. cardiac depressant (bradycardia, decreased cardiac output, decreased vascular resistance, transient hypotension)


11. high doses or rapid injection may cause significant respiratory depression and apnea


12. should give the initial bolus gradually over 1-2 minutes to effect and monitor respiratory rate and depth carefully during first few minutes after injection


13. muscle twitching during induction is not an indicator of inadequate anesthetic depth


14. good muscle relaxation


15. appetite stimulant at low doses


16. antiemetic properties


17. decreases intracranial and intraocular pressure


18. should be given with caution to animals with preexisting hypotension (shock, blood loss, dehydration)


19. cats can develop Heinz body production, diarrhea, and anorexia, and experience slow recoveries when given repeated doses


20. highly protein bound and should be used with caution in patients with significant hypoproteinemia


21. boluses may be repeated every 3-5 minutes up to 20 minutes


22. tranquilizer administration decreases the dose by about 75%


-Dissociative Anesthetics


1. ketamine may be given orally to feral cats to facilitate restraint


2. cause disruption of nerve transmission in some parts of the brain and selective stimulation in others


3. inhibit NMDA receptors in the CNS that are responsible for windup


4. produces a trace like state


5. ketamine peak action is 1-2 minutes after IV injection and 10 minutes after IM injection with a duration of 20-30 minutes, higher doses increase the duration but does not increase anesthetic effect


6. do not induce stage III anesthesia


7. palpebral, corneal, pedal, laryngeal, swallowing, and PLRs remain intact, even at moderate anesthetic depth


8. eye normally remains fully open with a central and dilated pupil


9. provide significant analgesia to the skin and limbs but limited organ analgesia


10. sensitive to sensory stimuli


11. don't decrease heart rate or decrease cardiac output in animals with normal heart function


12. cause increased heart rate and cardiac output and MAP, can be problematic for patients with preexisting heart disease (hyperthyroidism, cardiomyopathy)


13. apneustic respiration at higher doses


14. administration of benzodiazepines helps reduce exaggerated effects to sensory stimuli during recovery


15. contraindicated in epileptics due to the CNS stimulation


16. avoid in patients that have ingested strychnine, street drugs, organophosphates, and other toxins that affect the CNS


17. use with caution in patients undergoing procedures involving the neurologic system because they are at an increased risk for postoperative seizures


18. halucinations


19. may induce nystagmus


20. may decrease inotropy


21. slightly increase the risk that arrhythmias may develop


22. significantly increase salivation and respiratory tract secretions, anticholinergics may be used to control the secretions but may further predispose the patient to arrhythmias


23. increase intracranial and intraocular pressure, should not be used in patients with cranial trauma, conditions that cause elevated CSF pressure and some ocular surgeries


24. Ketamine


--excreted by the kidneys in cats and liver in dogs


25. Ketamine/Diazepam


--minimal cardiac depression, good muscle relaxation, superior recovery, and analgesia


--does not work well when given IM, because diazepam is not well absorbed, midazolam could be used in its place


26. Tiletamine


--sold only in combination with zolazepam


--zolazepam reduces the risk of seizures during recovery


-Etomidate


1. ultra short acting non barbiturate


2. noncumulative


3. duration of action of 3-5 minutes


4. decreases brain oxygen consumption and maintains brain perfusion better than mmost other injectable agents


5. anticonvulsant properties


6. little effect on heart rate, rhythm, blood pressure, and cardiac output


7. minimally affects respiratory rate and tidal volume


8. causes placental barrier but causes little neonatal respiratory depression


9. IV injection painful


10. rapid injection may cause RBC hemolysis in cats due to the propylene glycol vehicle


11. adrenal cortical function may be depressed for several hours after administrations decreasing levels of cortisol


12. nausea and vomiting may occure during induction or recovery


13. given to effect starting with one-quarter to one-half the dose


-Guaifenesin


1. muscle relaxant, minimally affecting the diaphragm


2. block nerves impulses in the CNS


3. IV injection can cause thrombophlebitis


INHALATION ANESTHETICS:


-cause dose related reversible depression of the CNS


-depress the temperature-regulating center leading to hypothermia


-depress cardiovascular function (decrease cardiac output, blood pressure, cause vasodilation)


-depress ventilation in a dose related manner


-head trauma or brain tumors may develop dangerously increased intracranial pressure, especially if carbon dioxide blood levels are allowed to increase


-potential to decrease renal perfusion which can be significant in animals with preexisting renal disease or receiving nephrotoxic drugs (genatmicin, NSAIDs)


-




Anticolinergics

-atropine: decrease in CNS activity, moderate cause of arrhythmias, low dose-temporary bradycardia, mild decrease in secretions (except for ruminants), will cross placental barrier


-glycopyrrolate: no decrease in CNS activity, mild arrhythmias, moderate decrease in secreations (except for ruminants), will minimally cross placental barrier


-moderate to marked increase in heart rate


-no analgesia


-no effect on temperature


-minimal to mild increase in blood pressure


-no effect on respiratory rate


-no effect on tidal volume


-moderate to marked decrease in GI motility (colic in horses, bloat in ruminants)


-bronchodilation


-thickening of secretions in felines and ruminants


-mild to moderate increase in mydriasis


-zero effect on muscle tone


-PLR may be depressed


-decreased lacrimal secretions


-provides no sedation or tranquilization


-does not ease induction or recovery


-does not decrease adverse effects and amount of general anesthetic required


-does not provide muscle relaxation


-minimizes bradycardia and salivation


-does not provide analgesia

Acepromazine

-moderate decrease in CNS activity in dogs, horses, and cows


-mild decrease in CNS activity in cats


-zero analgesia


-causes decreases in temperature


-can cause excitement, aggression, decreased seizure threshold


-mild decrease in heart rate


-mild increase in heart rate secondary to hypotension


-mild decrease in cardiac output


-mild to moderate decrease in blood pressure


-protects against arrhythmias


-vasodilator


-high doses may cause low heart rate in dogs


-no effect on respiratory rate unless given with other agents


-no effect on tidal volume unless given with other agents


-no effect on secretions


-mild decrease in gi motility


-antiemetic


-third eyelid prolapse


-decreased IOP


-no effect on muscle tone


-penile prolapse in horses and cattle


-slowly cross the placental barrier


-antihistaminic effect


-decreased PCV


-provides moderate tranquilization and sedation


-moderately eases induction and recovery


-mildly decreases adverse effects and amount of general anesthetic required


-provides no muscle relaxation


-does not minimize bradycardia and salivation


-does not provide analgesia

Benzodiazapines

-mild decrease in CNS activity in geriatric or dilapidated patients


-mild increase in CNS activity in young healthy patients


-no effect to mild decrease in intracranial pressure


-zero analgesia


-disorientation, aggression, ataxia, anticonvulsant activity


-no effect on heart rate (mild decrease if given rapidly IV)


-no effect on cardiac output


-no effect on blood pressure (mild decrease if given rapidly IV)


-no effect on respiratory rate (apnea if given rapidly IV)


-no effect on tidal volume


-no effect on secretions


-appetite stimulant (cats and cows)


-decreased intraocular pressure


-marked decrease in muscle tone


-premature parturition in cattle


-increased urine production


-crosses placental barrier


-transient hyperglycemia


-reaction to loud noises


-sweating and muscle tremors in horses


-provides mild tranquilization or sedation


-moderately eases induction and recovery


-mildly decreases adverse effects and amount of general anesthetic required


-provides moderate muscle relaxation


-does not minimize bradycardia and salivation


-does not provide analgesia

Alpha2-agonists

-marked decrease in CNS activity (small animals, small ruminants, and foals)


-mild increase in intracranial pressure due to vomiting


-moderate analgesia (short duration, somatic and visceral)


-decreases body temperature


-aggression, ataxia, cattle lie down, muscle tremors in horses


-marked decrease in heart rate


-moderate to marked decrease in cardiac output


-moderate to marked decrease in blood pressure


-moderate cause of arrhythmias


-initial hypertension resulting from vasoconstriction


-pale MM


-mild to moderate decrease in respiratory rate (especially ruminants)


-mild to moderate decrease in tidal volume (especially ruminants)


-no effect on secretions


-mild decrease in GI motility


-moderate cause of vomiting (cats over dogs)


-gastric distension in dogs


-bloat and regurgitation in cattle


-bloat and ileus in horses


-increased IOP due to vomiting


-marked decrease in muscle tone


-premature parturition in cattle


-increased urine production


-crosses placental barrier


-transient hyperglycemia


-reaction to loud noises


-sweating and muscle tremors in horses


-provides a great degree of sedation or tranquilization


-greatly eases induction and recovery


-greatly decreases adverse effects and amount of general anesthetic required


-provides moderate muscle relaxation


-provides moderate analgesia

opioids

-mild to marked decrease in CNS activity (mild increase at low doses)


-no effect on intracranial (mild increase if hypoventilating)


-marked analgesia (agonists)


-moderate analgesia (agonist/antagonists)


-somatic and visceral analgesia


-causes decreased temperature in dogs


-causes increased temperature in cats, horses, and ruminants


-disorientation in dogs if not in pain


-excitement/dysphoria in cats, horses, and ruminants


-mild to marked decrease in heart rate


-no effect on cardiac output


-no effect on blood pressure


-morphine causes hypotension secondary to histamine release


-mild decrease in respiratory rate


-mild decrease in tidal volume


-mild to moderate increase in secretions (small animals)


-stimulates gi motility then causes ileus


-moderate increase in vomiting (small animals)


-causes diarrhea then constipation


-causes miosis in dogs


-causes mydriasis in cats and large animals


-increased iop


-no effect on muscle tone


-urine retention


-decreased urine production


-slowly crosses placental barrier


-reactions to loud noises


-sweating in horses


-increased motor activity in horses


-provides mild to moderate tranquilization or sedation


-moderately eases induction and recovery


-moderately decreases adverse effects and amount of general anesthetic required


-provides no muscle relaxation


-does not minimize bradycardia and salivation


-provides a great amount of analgesia

barbiturates

-mild to marked decrease in CNS activity (mild increase at low doses)


-mild decrease in intracranial pressure (no effect if normal respirations)


-no analgesia


-decreased body temperature


-excitement during recovery and induction, especially if given too slowly


-mild decrease or increase in heart rate


-mild to marked decrease in cardiac output(dose dependent)


-mild to marked decrease in blood pressure (dose dependent)


-marked increase in arrhythmias


-moderate to marked decrease in respiratory rate (including apnea)


-moderate to marked decrease in tidal volume


-moderate to marked increase in secretions


-decrease in GI motility then increased


-sneezing and coughing


-decreased IOP


-no effect to mild decrease in muscle tone


-crosses the placental barrier


-tissue irritation if not injected IV

Propofol

-mild to marked decrease in CNS activity


-mild decrease in intracranial pressure


-no analgesia


-decreased body temperature


-muscular activity that resembles seizures


-mild decrease in heart rate


-mild decrease in cardiac output


-mild decrease in blood pressure (transient), may be moderately decrease in some patients


-may cause arrhythmia when given with epinephrine


-moderate to marked decrease in respiratory rate including apnea


-moderate to marked decrease in tidal volume


-no effect on secretions


-antiemetic


-decreased IOP


-moderate to marked muscle tone


-crosses placental barrier


-muscle twitching during induction in dogs

dissociatives

-both increase and decrease in CNS activity


-mild increase in intracranial pressure


-moderate analgesia somatic


-no to mild analgesia visceral


-decreased body temperature


-seizure like activity


-intact reflexes


-mild increase in heart rate


-mild increase in cardiac output


-mild increase in blood pressure


-mild increase in cardiac arrhythmias


-increased oxygen consumption


-decreased inotropy


-no effect on respiratory rate


-no effect on tidal volume


-moderate to marked increase in secretions


-apneustic respiration at high doses


-open, central, dilated eyes


-no to mild nystagmus


-increased iop


-no to marked muscle twitching


-crosses placental barrier


-increased sensitivity to sensory stimuli


-behavior changes during recovery

etomidate

-mild to marked decrease in cns activity


-no effect on intracranial pressure


-no to mild analgesia


-anticonvulsant activity


-decreased oxygen consumption


-no effect on heart rate


-no effect on cardiac output


-transient decrease in blood pressure, then no effect


-no effect on respiratory rate


-no effect on tidal volume


-no effect on secretions


-no effect on motility


-nausea and vomiting (induction and recovery)


-increased IOP


-moderate decrease in muscle tone


-crosses placental barrier


-excitement and muscle activity during induction and recovery


-IV injection painful

Guaifenesin

-mild decrease in CNS activity


-no analgesia


-transient increase in heart rate


-no effect on cardiac output


-transient decrease in blood pressure


-no effect on respiratory rate


-no effect on tidal volume


-no effect on secretions


-mild increase in GI motility


-apneustic respiration at high doses


-moderate decrease in muscle tone


-crosses placental barrier


-excitement during induction if used alone


-tissue irritation if not given IV

Halogenated inhalants

-mild to marked decrease in CNS activity


-mild increase in intracranial pressure


-no analgesia


-decreased body temp


-halothane: malignant hyperthermia in susceptible patients, moderate arrhythmia


-variable effects on heart rate


-mild to moderate decrease in cardiac output (dose dependant)


-mild to moderate decrease in blood pressure


-vasodilation


-mild to marked decrease in respiratory rate


-mild to marked decrease in tidal volume


-no effect on secretions


-mild decrease in gi motility


-Isoflurane: vomiting, mild to moderate decrease in muscle tone


-Desflurane: coughing


-crosses placental barrier


-Sevoflurane: excitement, muscle fasciculations during recovery

neuroleptanalgesi

a state of profound sedation and analgesia induced by the simultaneous administration of an opioid and a tranquilizer

Wind-up

exaggerated response to low-intensity pain stimuli that results in worsening of postoperative pain