EXAM #3 Prodigy Barash Flashcards
Through what inhibitory transmitter do inhalation and IV anesthetics exert their primary sedative and hypnotic effects?
GABA
Which narcotic is rapidly metabolized by blood and tissue esterases?
Remifentanil
Local anesthetics block the transmission of nerve impulses by targeting the function of voltage-gated _______ channels.
Sodium
Select two dose-dependent CNS depressant effects of benzodiazepines.
Hypnosis
Anticonvulsant activity
Which is the most important factor in the rate of rise of FA/FI?
Uptake
Which agent is notable for prolonging the duration of both intermediate and long-acting local anesthetics equally when added to their formulation?
Clonidine
Which of the following agents has been shown to increase intracranial pressure?
Desflurane
All have been shown to increase ICP
All volatile and N2O
2 IV agents decreasing ICP
Etomidate
Propofol
Which area is responsible for producing opioid-induced, postoperative nausea and vomiting?
Chemoreceptor Trigger zone
What may be responsible for the prolonged duration of action of vecuronium when used in intensive care unit patients?
Decreased Renal function
One of vecuronium’s metabolites,
3-OH vecuronium
3-OH vecuronium
accounts for about 60% of the activity of vecuronium and is excreted by the kidneys.The reduced clearance of this metabolite in the presence of altered renal status can result in a prolongation in the action of vecuronium.
Which of the following agents is a water-based prodrug of propofol?
Fospropofol, prodrug
Advantages of fospropofol include
Less bacteremia and HLD,less pain upon injection
After intravenous administration of fentanyl, there is an initial rapid increase in plasma concentration of the drug followed by a rapid decline in plasma administration. This initial, rapid decline is due primarily to
redistribution to highly-perfused organs
Once injected, the plasma concentration of an opioid such as fentanyl rises rapidly. Shortly after this initial rise, the plasma concentration rapidly
decreases as the drug is distributed into the highly perfused organs such as the brain, liver, and kidneys. A second, slower decrease in the plasma concentration occurs as the drug distributes into the less well-perfused tissues such as the muscles and adipose tissues
To what receptors does sugammadex bind?
It does not bind to any known receptors
Sugammadex is not known to have an affinity for any identified receptor, and it is biologically inactive. It binds
directly to steroidal neuromuscular blocking drugs.
Which of the following nondepolarizing muscle relaxants has an ED95 of 0.3 mg/kg?
Rocuronium
Simultaneous administration of a relatively slow agent such as isoflurane and a faster drug such as nitrous oxide (in high concentrations) to speed the onset of the slower agent is referred to as
2nd gas effect
Explain the 2nd gas effect?
Combined administration of a potent inhaled anesthetic with nitrous oxide can increase the alveolar concentration of the VA as the Nitrous exits the alveoli and enters the bloodstream more rapidly.
Which term describes the administration of a higher partial pressure of anesthetic than the alveolar concentration actually desired for the patient?
Overpressurization is the administration of a higher partial pressure of anesthetic than the alveolar concentration actually desired for the patient. This is used to speed induction.
All other factors being equal, which inhalation agent would exhibit the fastest emergence?
Desflurane
The elimination of the anesthetic is referred to as washout, and it’s primarily determined by the
solubility of the agent
The more soluble the agent is, the
greater it clings to the bloodstream and tissues.
The more soluble the agents the greater it clings to bloodstream and tissues, This is why emergence from a
poorly-soluble agent such as desflurane (blood:gas solubility = 0.42) occurs faster than a more soluble agent like isoflurane or sevoflurane.
Most clinicians, however, have found that gradually titrating a more soluble agent downward near the end of the case speeds
emergence.
When added to a local anesthetic, clonidine will
prolong long-acting and intermediate-acting agents equally
Local anesthetics block the transmission of nerve impulses by targeting the function of voltage-gated _______ channels.
Sodium
Which alpha-2 agonist produces analgesia via supraspinal and spinal adrenergic receptors?
Clonidine
Clonidine causes analgesia via
Supraspinal and spinal adrenergic receptors
What is the initial IV bolus of a 20 percent lipid emulsion for the treatment of local anesthetic cardiovascular toxicity?
1.5 ml/kg f/b infusion of 0.25 ml/kg/min for at least 10 minutes AFTER cardiac stability is maintained
What is the major metabolite of fentanyl?
Inactive metabolite NORFENTANYL
When administered as a premedication, the sympatholytic properties of dexmedetomidine may increase the incidence of intraoperative
Hypotension and BRADYCARDIA
Succinylcholine administration can increase the intraocular pressure
as much as 15 mmHg for about 5 minutes
All of the following are critical in determining the speed of emergence from inhalation anesthesia with a volatile agent
CO
Solubility of the agent
Minute ventilation
The lower the agent solubility, higher the cardiac output, and larger the minute ventilation, the
faster emergence will occur.
Unlike induction, in which you can use over-pressurization to speed the onset of anesthesia, you can’t under-pressurize at emergence simply because you cant
can’t reduce the inspired anesthetic below zero.
The post-tetanic count is
inversely related to the amount of time until a train-of-four twitch can be elicited
During profound neuromuscular blockade, the post-tetanic count is used to
estimate the time that is required before a response to stimulation will return.
The number of visible twitches correlates
inversely with the amount of time required for return of the first twitch of a TOF stimulation.
Which of the following is an expected respiratory effect of an inhaled anesthetic?
A decrease in tidal volume
Which opioid has the shortest half-life?
Remifentanil
Which term accurately describes the phenomenon that occurs during the recovery from anesthesia in which the washout of high concentrations of N20 can lower alveolar concentrations of oxygen and carbon dioxide?
Diffusion hypoxia
Select two treatments for an inadvertent intra-arterial injection of thiobarbiturates.
Heparin
Papaverine
Inadvertent intra-arterial injections of thiobarbiturates should be treated immediately with
intra-arterial papaverine.
Other treatment of inadvertent intra-arterial papaverine?
Heparinization as well as a sympathectomy induced by a regional anesthetic block should also be employed.
Select two agents that may shorten neuromuscular blockade in patients treated with chronic anticonvulsant therapy.
Carbamezipine
Phenytoin
Sevoflurane has been shown to produce late-phase cardiac preconditioning. What MAC level is needed to gain the maximum benefit of this effect?
1.5 MAC
Which neuromuscular blocking agent exhibits direct sympathomimetic and vagolytic effects?
Pancuronium
One of the most significant concerns with the use of nitrous oxide is its ability to.
expand an air-filled space. This can occur in any closed space that contains air including the bowel, an air embolus, or even the balloon in an endotracheal tube cuff.
During tympanoplasty, this agent contraindicated because the pressure can build up to the point that it dislodges the graft.
Nitrous oxide is contraindicated
What is the appropriate intravenous dose for succinylcholine in a 3 month-old patient?
2.0-3.0 mg/kg
Children and Defasciculating doses of nondepolarizing neuromuscular blockers
Defasciculating doses of nondepolarizing neuromuscular blockers are rarely given because fasciculations are uncommon in children
Which narcotic is rapidly metabolized by blood and tissue esterases?
Remifentanil is quickly metabolized by esterases in the tissues and bloodstream to a mildly active mu-opioid agonist and renally excreted metabolite
In general, most patients will not awaken from general anesthesia until what percentage of the anesthetic has been eliminated?
80-90%
Sevoflurane has been shown to demonstrate late-phase cardiac preconditioning. How long would you expect this cardioprotective effect to last?
24-48 hours