General Anesthesia 2 Flashcards
During the premedication phase, what class of drug is usually employed as an anxiolytic (which one)? What class of drug may be used in combination (which one)?
Benzodiazapine (midazolam)
Opioid (Fentanyl)
During induction, majority of induction agents first go to _ before redistributing to other parts of the body. In addition to an induction agent, what other drug may be administered at this time?
Brain
Muscle relaxant
During the maintenance phase of anesthesia, _ and _ are used in addition to a volatile anesthetic because of their MAC sparing properties?
Muscle relaxant
Opioid
What occurs to the anesthetics that allows for the emergence and recover phase? Why do patients emerge quickly from anesthesia?
Drug elimination and metabolism
The drugs quickly redistribute from the brain
What property of volatile anesthetics allow them to quickly accumulate in the brain?
Lipid solubility
The newest anesthetic induction agent, this agent is used for induction and sometimes for maintenance and sedation. It produces cardiovascular and respiratory depression and cannot be antagonized. What is this drug? What is it usually dissolved in? What makes it unique among anesthetic agent?
Propofol
Intralipid
No “hang over”
This anesthetic is adminstered intravenously and used mainly for induction. It produces respiratory depression but not cardiovascular depression. It cannot be antagonized. This describes _. What should you NOT use this drug for?
Etomidate
Sedation
This anesthetic is and NMDA receptor antagonist and is described as a dissociative anesthetic. Used for induction, and produces sedation, amnesia and analgesia. It doesn’t produce either respiratory or cardiovascular depression and it cannot be antagonized. It is associated with emergence delirium. This describes _
Ketamine
What are the 2 examples of barbiturates provided? What are their subgroups?
Methohexital (Oxybarbiturate)
Thiopental (Thiobarbiturate)
How are barbiturates administered? What part of the anesthesia protocol are they used for? What property allows them to produce rapid, profound unconsciousness due to rapid uptake into the brain? What is their effect on cardiovascular depression? Respiratory depression?
IV Induction Lipid soluble N/A Profound respiratory depression
Recovery from barbiturates is rapid (5-8 mins). What causes this? How are they antagonized? What is their effect on parasymp outflow from the brain? Symp outflow?
Redistribution from the brain
Cannot be antagonized
No mentioned effect on parasymp
Decrease sympathetic outflow
Propofol, ketamine, etomidate, benzodiazapines and barbiturates. What receptors do these drugs work on?
All but Ketamine (NMDA) function at GABA receptor
What part of the anesthesia protocol are benzodiazapines used for? Which do they produce (analgesia, sedation, amnesia)? What is their effect on cardiovascular depression? Respiratory depression? What is the drug that can antagonize their effect?
Premedication (anxiolytic) Sedation and amnesia No mentioned effect on cardiovascular Depress repiration Flumenazil
How does Fentanyl compare to morphine with regards to:
- Lipid solubility
- Onset of action
- Potency
- Duration of action
- Higher lipid solubility
- Fast onset
- High potency
- Shorter duration of action
Ordinarily, what causes the termination of fentanyl’s effects? What drug can be used to antagonize its actions?
Redistribution
Naloxone
What part of the anesthesia protocol is fentanyl used for? How does it affect volatile anesthetics? What is their effect on cardiovascular depression? Respiratory depression?
Premedication
Reduces MAC requirements
No mentioned effect on cardiovascular
Marked respiratory depression
What are 2 drugs comparable to fentanyl i.e. potent, fast
onset, short acting opioids?
Sufentanil
Alfentanil
What is an opioid that can be used as an infusion? What enzyme metabolizes it?
Remifentanil
Plasma esterase
What class of drug is usually used when placing a tube down throat with a laryngoscope? What reflex is blocked by this class of drugs?
Muscle relaxant
Blocks cough reflex
What is the purpose of an opioid that is used during the maintenance phase of anesthesia?
Used for MAC sparing effects
What is a major difference between the general anesthetics and the induction agents?
Induction agents are lipid soluble, anesthetics are not
Despite lipid solubility, why won’t fat take up a lot of lipid soluble induction agents?
There isn’t a lot of blood flow to fat to deliver the drug in the first place
Etomidate is an anesthetic that doesn’t produce cardiovascular depression. What group of patients may this drug be good for? What drug that doesn’t produce respiratory or cardiovascular depression may also be good for this group of patients?
Patients who are hemorrhaging, cardiogenic shock, sepsis or hypotension
- Ketamine
Despite being an NMDA antagonist, why can’t ketamine be antagonized? What is the characteristic of the ketamine EEG?
It is a non-competitive antagonist
Described as unusual
Beyond midazolam, what are 2 other benzodiazepines used in anesthesia?
Diazepam
Lorazepam
It is generally hard to overdose on benzodiezapines. Under what conditions does this rule not apply (2)?
When they are combined with alcohol and or opioids
When they are administered IV
Fentanyl is used in anesthesia. Why is it notconsidered an anesthetic?
It doesn’t produce amnesia
