L5: Injectable Anesthetics (Garcia) Flashcards
general chars. of anesthetics
- very liposoluble
- highly protein bound
- reach brain rapidly
- redistr. to other tissue
graphs slide 3/4
:)
-IV anesthetic redistributes to brain/vascular rich areas first, then muscle, then fat
Q: if there is a single bolus of anesthetic, what is most pertinent mech. or animal waking up?***
A: redistribution to other site
chars. of propofol
- 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
MOA of propofol
- acts on GABA receptors
- increases influx of Cl- –> hyperpolarization
metabolism of propofol
extra-hepatic
-safe for CRI
CV effects of propofol
- myocardial depression
- dec. CO, MP
- inc. HR (as compensation or low BP)
resp. effects of propofol
- decrease in tidal volume
- hypoventilation (–> CO2)
- apnea
neurologic effects of propofol
- decrease CMR, ICP, EEG activity, CPP (cerebral profusion pressure)
- protective for brain ischemia
- effects due to action on GABA receptors
- tx for seizures
chars. of ketamine
- causes dissociation b/w thalamus and limbic system
- large therapeutic index
- can be given IM
metabolism of ketamine
dogs: hepatic
cats: eliminated unchanged (caution for renal failure cats)
CV effects of ketamine
- sympathetic stimulation
- inc. HR and BP
- direct myocardial depressant
- may increase Intraocular P
- not rec. in cats with hypertrophic cardiomyopathy (HCM)
resp. effects of ketamine
- 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
neuro effects of ketamine
- inc. ICP and Cerebral blood flow
- somatic analgesia
- excitement at emergence
clinical effects of ketamine
- inc. salivation and mucus
- poor m. relaxation
- reflexes maintained
- rough recoveries (esp. in cats)
- often combined with benzos
chars. of telazol
- act on same sites of action as ketamine/valium
- 1:1 tiletamine: zolazepam
CV effects of telazol
- similar to ketamine
- inc. HR, BP and systemic vascular resistance due to sympathetic stimulation
Neuro effects of telazol
-maintained coughing, swallowing, corneal reflexes
resp. effects of telazol
-similar to ketamine
chars. of etomidate
- acts on GABA receptors
- propylene glycol based
- causes hemolysis
- expensive
CV/resp. effects of etomidate
- CV and resp. stability
- adrenal suppression (Addisonian crisis)
Neuro effects of etomidate
- generally CNS friendly
- myoclonus (involuntary jerking)
- poor m. relaxation
- usually combined w/ benzo or opioids
chars. of alfaxalone
- neurosteroid in ciclodextrin
- acts on GABA
CV effects of alfaxalone
- minimal
- inc. HR, CO
- dec. BP (vasodilation)
- dose dependent resp. depression
neuro effects of alfaxalone
- CNS friendly
- potential protective effect in premature fetus when labor induced by steroids
- excitation in cats during recovery
chars. of injectable opioids like fentanyl, hydromorphone
- narcosis, not anesthesia
- CV friendly
- dec. HR
- resp. depression
- analgesia
- used in sick patients
- reversible
- fentanyl short acting
