Injectable anesthetics (Garcia)

Question 1

Anesthetics are

Answer 1

1. very liposoluble
2. highly protein bound
3. reach the brain rapidly
4. redistributed to other tissue
   
   • muscle
5. accumulation in fat

Question 2

Hypoproteinemic dogs

Answer 2

• need less drugs
  
  • more free drug in bloodstream

Question 3

Propofol

Answer 3

• alkylphenol compound
• insoluble in water
• egg lecithin
  
  • contamination
  • 6 hours opened => throw away
• shelf life 3 yrs

Question 4

Effects of propofol

Answer 4

• induction in 30 seconds
• bolus to avoid excitation
• apnea => not a big deal if intubated and no brain tumor
• duration => 10-15 min
• Cumulative
• splenic engorgement

Question 5

Gaba

Answer 5

• main system of inhibitory neurons
  
  • gabanergic drugs tent to inhibit inhibitory neurons first = excitation
  • give fast bolus of 1/3 of dose to avoid excitation
    
    • benzos also

Question 6

Benzos have minimal

Answer 6

cardiovascular effect

Question 7

metabolism

Answer 7

• when a patient has a CRI of propofol for several days, waking up depends on metabolism, not redistribution

Question 8

Propofol blocks

Answer 8

• sypathetic nervous transmission
• alpha receptors

Question 9

Drugs that cause splenic engorgement

Answer 9

• propofol
• acepromazine

Question 10

Ketamine

Answer 10

• cyclohexamine
• dissociation between thalamus and limbic system
• hepatic metabolism in dogs and horses
• eliminated unchanged by cats
• large therpeutic index
• can be given IM

Question 11

Remeber that with ketamine you will not stop

Answer 11

palpebral reflex

Question 12

You have to be careful about using ketamine in cats with

Answer 12

renal failure

Question 13

Ketamine and cardiovascular

Answer 13

• sympathetic stimulation
• inc HR and BP
• careful in HCM and renal failure (Cats)
  
  • increase oxygen demand in thick muscle. Leads to infarc.
• Direct myocardial depressant
• may inc IOP
  
  • avoid with glaucoma and p w/ inc intracranial pressure
• arrhythmogenic

Question 14

Ketmine and respiratory

Answer 14

• Apneustic breathing
• Apnea
• Maintained laryngeal reflexes and PaO₂
  
  • ​still swallows
  • may be difficult to intubate

Question 15

Ketamine and neurologic

Answer 15

• inc ICP and CBF
• Somatic analgesia
• Excitement at emergence
  
  • motor activity
  • Sensitivity to touch
  • violent recovery

Question 16

Ketamine Clinical effects

Answer 16

• inc salivation and mucus
• poor muscle relaxation
• reflexes are maintained
• rough recoveries
• often combined with benzos

Question 17

Telazol

Answer 17

• same sites of action as ketamine/diazepam
• 1:1 combo
  
  • tiletamine
  • zolazepam
• lyophilized powder
• reconstituted with sterile water

Question 18

Telazol cardiovascular

Answer 18

• similar to ketamine
• inc HR, BP and SVR
• due to sympathetic stimulation

Question 19

Telazol neurologic

Answer 19

• maintained reflexes
  
  • coughing
  • swallowing
  • corneal reflexes

Question 20

Telazol respiratory

Answer 20

similar to ketamine

Question 21

Etomidate

Answer 21

• Acts on GABA A receptors
• Propylene Glycol based
• Hemolysis
  
  • propylene glycol-osmolality
• Imidazole derivative
• Expensive

Question 22

Etomidate used primarily in …….. patients

Answer 22

cardiovascular

Question 23

Etomidate and cardiorespiratory

Answer 23

• cardiovascular and respiratory stability

Question 24

Etomidate and neurologic

Answer 24

• CNS friendly
• Myclonus
  
  • poor muscle relaxation
• Usually combined with benzos or opioids

Question 25

Etomidate other side effects

Answer 25

* adrenal suppression * be careful of an addisonian crisis

Question 26

Don't use etomidate in a septic patient because of its

Answer 26

adrenal suppression

Question 27

Alfaxalone

Answer 27

* similar to propofol * very expensive * Neurosteroid in ciclodextrin * act on GABA * relaxation is better than ketamine

Question 28

Alfaxalone cardiorespiratory

Answer 28

* minimal cardiovascular effects * inc HR and C.O. * dec BP (vasodilation) * Dose dependent respiratory depression * apnea after bolus

Question 29

Alfaxalone Neurologic

Answer 29

* CNS friendly * potential protective effect in premature fetus when labor is induced by glucocorticoids (Betamethasone) * Excitation in cats during recovery (IM route)

Question 30

Opioids are a good alternative for a .....

Answer 30

sick patient

Question 31

Opioids

Answer 31

* Narcosis not anesthesia * cardiovascular friendly * dec HR, respiratory depression * can be treated with anticholinergics * analgesia * used in sick patients * cardiovascular compromised * reversible * short actig (fentanyl)

Question 32

Propofol summary

Answer 32

* Fast acting * No problem if given perivascular * short cardiovascular depression * apnea, respiratory depression * CNS friendly * Contamination

Question 33

Ketamine summary

Answer 33

* Inc sympathetic tone * Poor muscle relaxant * Combine with Benzodiazepines for induction * Increase mycardium work load * Increase ICP, CBF, IOP, dec seizures threshold * Rough recoveries * Apneustic breathing, apnea * Maintained reflexes

Question 34

Telazol summary

Answer 34

* similar effects of Ket/val * Smaller volume * Associated with rough recoveries w/o premeds * Can be reconstituted with Ketamine and alpha₂s

Question 35

Etomidate summary

Answer 35

* minimal cardiovascular changes * adrenal depression * poor muscle relaxant * combined with opioid or benzo for induction * expensive * good for cardiac patients

Question 36

Opioids summary

Answer 36

* Fentanyl and hydromorphone bolus * dec HR and ventilation * no myocardial depression * reversible * analgesic * short acting (fentanyl)