L5: Injectable Anesthetics (Garcia)

Question 1

general chars. of anesthetics

Answer 1

• very liposoluble
• highly protein bound
• reach brain rapidly
• redistr. to other tissue

Question 2

graphs slide 3/4

Answer 2

:)

-IV anesthetic redistributes to brain/vascular rich areas first, then muscle, then fat

Question 3

Q: if there is a single bolus of anesthetic, what is most pertinent mech. or animal waking up?***

Answer 3

A: redistribution to other site

Question 4

chars. of propofol

Answer 4

• alkylphenol compound
• insoluble in water
• spoils if left out >6hrs due to egg lecithen
• unopened shelf life: 3yrs
• 5-10 min. of anesthesia after induction dose
• short half life

Question 5

MOA of propofol

Answer 5

• acts on GABA receptors

- increases influx of Cl- –> hyperpolarization

Question 6

metabolism of propofol

Answer 6

extra-hepatic

-safe for CRI

Question 7

CV effects of propofol

Answer 7

• myocardial depression
• dec. CO, MP
• inc. HR (as compensation or low BP)

Question 8

resp. effects of propofol

Answer 8

• decrease in tidal volume
• hypoventilation (–> CO2)
• apnea

Question 9

neurologic effects of propofol

Answer 9

• decrease CMR, ICP, EEG activity, CPP (cerebral profusion pressure)
• protective for brain ischemia
• effects due to action on GABA receptors
• tx for seizures

Question 10

chars. of ketamine

Answer 10

• causes dissociation b/w thalamus and limbic system
• large therapeutic index
• can be given IM

Question 11

metabolism of ketamine

Answer 11

dogs: hepatic
cats: eliminated unchanged (caution for renal failure cats)

Question 12

CV effects of ketamine

Answer 12

• sympathetic stimulation
• inc. HR and BP
• direct myocardial depressant
• may increase Intraocular P
• not rec. in cats with hypertrophic cardiomyopathy (HCM)

Question 13

resp. effects of ketamine

Answer 13

• apneustic breathing (wiki: abnormal pattern of breathing characterized by deep, gasping inspiration with a pause at full inspiration followed by a brief, insufficient release)
• apnea
• maintained laryngeal reflexes and PaO2

Question 14

neuro effects of ketamine

Answer 14

• inc. ICP and Cerebral blood flow
• somatic analgesia
• excitement at emergence

Question 15

clinical effects of ketamine

Answer 15

• inc. salivation and mucus
• poor m. relaxation
• reflexes maintained
• rough recoveries (esp. in cats)
• often combined with benzos

Question 16

chars. of telazol

Answer 16

• act on same sites of action as ketamine/valium

- 1:1 tiletamine: zolazepam

Question 17

CV effects of telazol

Answer 17

• similar to ketamine

- inc. HR, BP and systemic vascular resistance due to sympathetic stimulation

Question 18

Neuro effects of telazol

Answer 18

-maintained coughing, swallowing, corneal reflexes

Question 19

resp. effects of telazol

Answer 19

-similar to ketamine

Question 20

chars. of etomidate

Answer 20

• acts on GABA receptors
• propylene glycol based
• causes hemolysis
• expensive

Question 21

CV/resp. effects of etomidate

Answer 21

• CV and resp. stability

- adrenal suppression (Addisonian crisis)

Question 22

Neuro effects of etomidate

Answer 22

• generally CNS friendly
• myoclonus (involuntary jerking)
• poor m. relaxation
• usually combined w/ benzo or opioids

Question 23

chars. of alfaxalone

Answer 23

• neurosteroid in ciclodextrin

- acts on GABA

Question 24

CV effects of alfaxalone

Answer 24

• minimal
• inc. HR, CO
• dec. BP (vasodilation)
• dose dependent resp. depression

Question 25

neuro effects of alfaxalone

Answer 25

• CNS friendly
• potential protective effect in premature fetus when labor induced by steroids
• excitation in cats during recovery

Question 26

chars. of injectable opioids like fentanyl, hydromorphone

Answer 26

• narcosis, not anesthesia
• CV friendly
• dec. HR
• resp. depression
• analgesia
• used in sick patients
• reversible
• fentanyl short acting