Term
| What are the 5 indications for injectable anesthesia? |
|
Definition
-induction for inhalation anesthesia
-induction +/- maintenance of nesthesia
-procedures involving airways
-economics
-portability |
|
|
Term
| Describe the ideal injectable anesthetic? |
|
Definition
| -unconsciousness, muscle relaxation, aalgesia, homeostasis, easily eliminated, short duration/minimal cumulative effects, reversible, wide margin of safety, inexpensive |
|
|
Term
| What class of drugs is known as dissociative anesthetics? Example? |
|
Definition
-Cyclohexamines
-ketamine, tiletamine |
|
|
Term
| Describe the overall effects of dissociative anesthetics. |
|
Definition
| -catalepsy, profound peripheral analgesia, and altered consciousness |
|
|
Term
| What are some of the negative CNS effects of dissociative anesthetics? |
|
Definition
-inc intracranial pressure
-may inc brain metabolic activity
-may inc intraocular pressure
-causes seizure activity in non-sedated dogs or horses |
|
|
Term
| Do dissociative agents have good somatic analgesia, visceral, or both? |
|
Definition
|
|
Term
| What are some of the negative CV effects of dissociative agents? |
|
Definition
-inc HR, contractility
-requires functional sympathetic system
-marked inc in myocardial oxygen demand
-minimal dysrhythmogenicity
-myocardial depression at high doses |
|
|
Term
| What are some of the negative respiratory effects of dissociative agents? What about metabolic effects? |
|
Definition
-apneustic breathing pattern, laryngospasm, inc saivation, resp seretions
-majority is excreted unchanged in felines, extensive hepatic met in most species |
|
|
Term
| How long do IV and IM Ketamine Last? Same for Telazol? |
|
Definition
-Ketamine: IV = 5-10 min & IM = 20-30 min
-Telazol: IV = 10-15 min & IM = 20-40 min |
|
|
Term
| What are the benefits of using dissociative agents? |
|
Definition
-wide margin of safety due to CV effects
-good choice for debilitated/critical patients
-inexpensive
-good for heavy sedation in horses and dogs |
|
|
Term
| Which injectable anesthetic is known as the "milk of amnesia"? Shelf life? |
|
Definition
-Propofol
-without preservative = 10h, with preservative = 28d |
|
|
Term
| What are the CNS effects of propofol? |
|
Definition
-sedative-hypnotic
-GABA-ergic
-dec CNS met actiity
-moderate muscle relaxaiton |
|
|
Term
| What are the CV effects of Propofol? resp effects? |
|
Definition
-dec contractility, vasodilation, transient hypotension, no arrhythmogenicity
-transient apnea, hemoglobin desaturation |
|
|
Term
| How is propofol metabolized/excreted? |
|
Definition
-rapid redistribution from brain
-rapid metabolism: hepatic, non-hepatic, lung |
|
|
Term
| Describe te duration of action of Propofol. |
|
Definition
-very short duration: 10 min
-can be redosed or used as infusion
-can be used in "lean" animals |
|
|
Term
| How bad or good is the margin of safety of Propofol? |
|
Definition
|
|
Term
|
Definition
|
|
Term
| What is the major concern with treating cats with Propofol? |
|
Definition
-may produce blood dyscrasiasis (Heinz body formation)
-do not use repeatedly in cats |
|
|
Term
| What type of drug is Etomidate? |
|
Definition
|
|
Term
| Which injectable anesthetic is consdidered ideal for critical patient? Why? |
|
Definition
-Etomidate
-good margin of safety due to CV stability and short duration |
|
|
Term
| What is the downside of Etomidate? |
|
Definition
| -expensive (no vet preparation) |
|
|
Term
| What are the CNS effects of Etomidate? |
|
Definition
-GABA receptor complex related
-inc EEG activity in epileptogenic areas: may produce seizure-like activity
-decreases brain metabolic activity, oxygen consumption |
|
|
Term
| What are the CV effcts of Etomidate? Resp effects? Musculoskeletal? |
|
Definition
-NONE, maybe slight vasodialtion
-minimal resp depression
-moderate muscle relaxation |
|
|
Term
| Describe the endocrine effects of Etomidate? |
|
Definition
-inhibits cortisol production in humans
-no longer used as continuous rate infusion to maintain general anesthesia due to profound, persistent suppression of adrenocortical steroid synthesis with potentially lethal consequences in critically ill patients |
|
|
Term
| How is Etomidate excreted? |
|
Definition
-hepatic metabolism
-renal excretion of metabolites |
|
|
Term
| Describe the duration of action of Etomidate. |
|
Definition
=short duration: 5 min (dose dependent)
-may be re-dosed, but infusion is no longer recommended in human anesthesia |
|
|
Term
| What is Alfaxalone historically paired with? |
|
Definition
|
|
Term
| How does Alfaxalone work? |
|
Definition
| -neurosteroid general anesthetic with no steroid effects |
|
|
Term
| What are the CNS effects of Alfaxalone? |
|
Definition
-rapid onset, sedation at lower doses (IM)
-binds to GABA neuronal cell surface receptors: modulation of neuronal cell membrane chloride ion transport & binds to a different region of this receptor than benzodiazepines |
|
|
Term
| What are the CV effects of Alfaxalone? |
|
Definition
-minimal hypotension, changes in HR
-do not see desaturation associated with propofol
-no adverse effects (blood dyscrasias) seen in cats with prolonged administration of propofol
-good alternative to etomidate |
|
|
Term
| What are the repsiratory effects of Alfaxalone? |
|
Definition
| -minimal respiratory depression |
|
|
Term
| How is Alfaxalone metabolized? When is its peak effect? |
|
Definition
-very short plasma-elimination half life
-approx 5 min
-rapidly metabolized by livr |
|
|
Term
| How do we admin Alfaxalone? |
|
Definition
-licensed for IV injection for dogs, cats
-titrate to effect |
|
|
Term
| Alfaxalone is most effective when administered how? Any combos? |
|
Definition
-IM
-recommen combo with midazolam or opioid |
|
|
Term
| How do we store Alfaxalone? |
|
Definition
-shelf life 30 months, store below 30 degrees C (room temp)
-protect from light
-contains no preservatives: open vial used within 24 hrs (preferred) & open vial may be stored at 4 deg C for up to 7 days provided contamination in avoided |
|
|
Term
| How does Chloral Hydrate work? |
|
Definition
-depresses the cerebrum wiht loss of reflex excitability
-good sedative-hypnotic, poor anesthetic: amount to produce anesthesia approaches the minimum lethal dose & not a satisfactory surgical anesthetic |
|
|
Term
| What are the effects of Chloral Hydrate use? |
|
Definition
-decreases BP
-dose-dependent depression of respiration
-best used to produce narcosis or sedation as adjunct to regional analgesia/anesthesia |
|
|
Term
| What kind of drug is Guaifenesin? |
|
Definition
-technically a sedative-hypnotic, but does not progress to unconsciousness when used for induction by itself
-centrally-acting muscle relaxant
-expectorant |
|
|
Term
| What are some examples of anesthetic combinations? |
|
Definition
-fentanyl/ketamine + midazolam or lidocaine
-propofol + ketamine
-butorphanol/lidocaine/ketaimine
-Triple Driop = ketamine, xylazine, guaifenesis |
|
|
