(06) Injectable Anesthetics Flashcards
1
Q
- thiopental has a high or low lipid solubilty?
- Phenobarbital?
- Thiopental is more rapidly absorbed from the gut than Phenobarbital, but isn’t used why?
- Phenobarbital is absorbed much more slowly from the gut but can be used by this oral route for its longer term therapeutic uses.
A
- Thiopental has a high lipid solubility with a partitian coefficient of about 580.
- has a low lipid solubility with a partitian coefficient of 3.
- still slow enough that it is not used by this route.
2
Q
- After an IV injection, thiopental rapidly induces its maximal CNS effects compared to phenobarbital, but what?
A
- these effects wear off rapidly
3
Q
- thiopental vs. phenobarb - what has a higher degree of plasma protein binding?
thus what?
A
- thiopental
therefore more likely to displace other compounds that are also protein bound.
4
Q
- what play major role in the termination of phenobarbital’s action?
- After a single injection of thiopental, what is primarily responsible for the termination of its anesthetic affect?
- Phenobard has a high ability to induce what after repeated use?
- Thiopental has a high ability to induce what after prolonged therapy?
A
- Excretion and metabolism
- redistribution
- liver enzymes
- CNS tolerance
5
Q
- In light of its typical patient population, its is important to indicate to the cline that a sudden lapse in compliance may lead to seizures during treatment with what?
- phenobarb binds to what receptor? does what?
3.
A
- phenobarb
- GABA
inhibits epileptic foci, transmitter release, increases the duration of chloride channel open time
6
Q
- All 12. All excitable tissues are affected by barbiturates, but of those what is the lease sensitive to the barbiturates like thiopental
- thipental would be more useful as an inducing agent than long acting barbiturates
- In determining the degree of depression that barbiturates will produce in an accident victim, what are important things to consider?
A
- skeletal muscle
- the patients history of epilepsy, the dose of the drug, the patient’s state of shock and the route of drug administration are all important factors to consider.
7
Q
- Because of their effects on excitable tissue, barbiturates tend to do what?
A
- decrease intestinal motility during surgery, decrease uterine contractions and produce reflex hypermotility, spasms and vomiting during recovery.
8
Q
- If injected rapidly, thiopental produces what during normal use as an anesthetic?
What might be useful in a post-orthopedic situation as it induces good skeletal muscle relaxation?
What can decreae BP during the course of its normal use at anesthetic doses?
A
- respiratory depression and transient apnea
Diazepem
thiopental
9
Q
- If readministered to achieve a longer drug effect, each subsequent dose of thiopental produces a longer or shorter anestheic effect?
- true/false - 18. Unlike gas anesthetics and propofol, thiopental need not be administered continuously to maintain anesthesia.
A
- longer
- true!
10
Q
- Ketamine is a common sedative in cats that can be injected by many routes but does what when injected IM?
- As an anesthetic, it usually requires what to reduce profuse salivation?
- Ketamine is analgesic, dysphoric, and hallucinogenic
- In cases of brain injury, ketamine may not be used why?
A
- stings
- premedication with atropine
- it increases blood pressure and intracranial pressure.
11
Q
- Are shorter or longer effects produced by each repeated injection of ketamine?
- is ketamine analgesic at sedative doses?
- although ketamine inhibits excitatory amino acid activity and results in anestheisia, other compunds that similarly inhibit NMDA sites do not produce anesthesia. Ketamine is usually contraindicated in animals with a history of seizure disorders
A
- shorter
- yes
