Exam # 3 Prodigy Nagelhout Flashcards
Which A-type fibers are the most myelinated and largest in diameter?
A-Alpha
When a volatile anesthetic is administered to a patient undergoing EEG monitoring, there is an initial ______ in amplitude followed by a(n) _________ in both frequency and amplitude.
increase, decrease
All volatile anesthetics suppress the.
electroencephalogram (EEG) in a dose-dependent manner
At about 2.0 MAC, the EEG may temporarily exhibit what ? What is it refer to as?
electrical silence. This is referred to as burst suppression.
Which cholinesterase inhibitor has the shortest duration of action?
Edrophonium
Has the fastest onset and shortest duration of action for the cholinesterase inhibitor?
Edrophonium
Why is edrophonium not use as a reversal agent?
low doses of the drug should not be administered for primary reversal of muscle relaxants as the muscle relaxant could outlast the duration of the reversal.
Which of the following is a potential side effect from the use of eutectic mixture of local anesthetic (EMLA) cream?
Decreased oxygen saturation reading
Because EMLA cream contains prilocaine, it can result in
methemoglobinemia.
Methemoglobinemia has equal absorbent coefficient ratios for both
red and infrared wavelengths and results in a false pulse oximetry reading that tends to equal 85%.
Methemoglobinemia can result in falsely low pulse oximetry readings when the actual oxygen saturation is
higher than 85% and falsely high readings when the oxygen saturation is lower than 85%.
Which local anesthetic produces vasoconstriction, shrinks the mucosa, and helps facilitate nasal surgery?
Cocaine
The only naturally occurring local anesthetic? In fact, it is
Cocaine
Main action of cocaine on catecholamines ?
Blocks the reuptake of catecholamines in adrenergic neurons, resulting in vasoconstriction.
Main use of cocaine?
Its main use is for topical anesthesia for the nose and throat
Used in more than 50% of rhinolaryngologic procedures in the US.
Cocaine
What is the most common side effect of neuraxial opioids?
Pruritus
Pruritus caused by neuraxial opioids typically is concentrated on the
face, neck, and upper chest but can be distributed throughout the entire body.
Pruritus more common in these types of patients?
It is most common in obstetric patients, presumably from the combined pruritic effect of estrogen.
Which nondepolarizing muscle relaxant is metabolized predominantly by ester hydrolysis?
Atracurium
A small amount of Cisatracurium may be metabolized by_______
Plasma esterases
The primary route of metabolism is Hofmann elimination.
Atracurium
Most heavily on nonspecific esterases for its metabolism
Amount of Atracurium, on the other hand,
Primary metabolism of ATRACRURIUM
Nonspecific Plasma esterase
Only about 10-40% undergoes Hofmann elimination
Cisatracurium
Rocuronium is eliminated primarily in the
bile.
Vecuronium is metabolized to a small extent by the
liver and depends upon
Excretion of vecuronium
biliary and renal excretion.
Which of the following anesthetic formulations is most susceptible to bacterial growth?
Propofol
Propofol is prepared as a
lipid emulsion of soybean oil, glycerol, and egg lecithin with a pH between 7 and 8.5.
Why does propofol contains EDTA, metabisulfite, or benzyl alcohol?
to help prevent bacterial growth.
What substances, when added to a local anesthetic solution, will prolong the local anesthetic duration of action? 2
Epinephrine
Phenylephrine
The addition of dextran to a local anesthetic solution increases the
duration of action.
The addition of a vasoconstrictor such as epinephrine and phenylephrine will _______ of LA
prolong the effect of local anesthetics.
The addition of hyaluronidase facilitates the
spread of the local anesthetics into the tissue and speeds the onset of the block.
Which organs are primarily responsible for excreting opioids and their metabolites?
Kidneys
Oil:gas partition coefficient of Isoflurane is
99 (some sources cite 98)
Oil:gas partition coefficient of desflurane
Desflurane = 18.7
Oil:gas partition coefficient of Sevoflurane
Sevoflurane = 50 (some source cite 55),
Oil:gas partition coefficient of Nitrous oxide
Nitrous oxide = 1.4
Which of the following will exacerbate local anesthetic toxic reactions? (select two)
Hypoxia
Hypercapnia
Triad of LA toxicity is
Hypoxia, hypercapnia, and acidosis
Utmost importance in the management of inadvertent local anesthetic overdose.
Airway control
Which of the following local anesthetics are hydrolyzed in plasma by cholinesterase systems?
Amino ester local anesthetics (chloroprocaine, procaine, benzocaine) are hydrolyzed in the plasma by pseudocholinesterase.
What are the amide LAs?
lidocaine, prilocaine, bupivacaine, ropivacaine
The amide local anesthetics are primarily metabolized in
the liver.
What is the approximate blood/gas partition coefficient of sevoflurane?
0.68
Following administration of morphine for pain, a patient complains of pruritus. Which agent would be the most appropriate to alleviate the itching?
nalbuphine
Can eliminate opioid-induced pruritus, they may also reverse the analgesia of the opioid.
Naloxone and naltrexone
Nalbuphine has been shown to be more effective than diphenhydramine, propofol, and naloxone in treating pruritus and does not
reverse analgesia.
The alveolar concentration of anesthetic that blunts adrenergic responses to noxious stimuli is termed as:
MAC BAR
MAC-BAR95 is the dose that prevents an
adrenergic response in 95% of patients.
Which opioid is most likely to cause histamine release?
Morphine
Morphine causes histamine to be released from mast cells. This results in
redness, generalized flushing, local itching, or hives near the site of injection.
Which local anesthetic only exists in a nonionized state?
benzocaine
It is able to pass into the cell membrane and block the sodium channel directly without entering the axoplasm.
Benzocaine
Which local anesthetic agent causes vasoconstriction?
With the exception of cocaine, ropivacaine, and lidocaine, all local anesthetics produce vascular smooth muscle relaxation.
Select the two local anesthetics that are found in Eutectic Mixture of Local Anesthetics (EMLA).
Lidocaine
Prilocaine
EMLA is a mixture of
2.5% prilocaine and 2.5% lidocaine. It is applied to the skin via patch or cream.
Which volatile anesthetic produces the least amount of coronary vasodilation?
Sevoflurane
All produce vasodilation of the coronary arteries, with sevoflurane producing the least coronary dilation.
Isoflurane, sevoflurane, and desflurane
Rank the intravenous agents in order with number one being the greatest degree of protein binding and number four the least.
From greatest to least, the degree of protein-binding is as follows: Propofol > Midazolam > Etomidate > Ketamine
Which of the following statements regarding fentanyl are true? (select two)
Termination of its effects are predominantly via hepatic metabolism
Peak effect of fentanyl
3-5 minutes
Fentanyl undergoes extensive first-pass metabolism, so the oral route is typically
insufficient for administration.
Solubility of Fentanyl
Because it has a high lipid solubility
Which of the following local anesthetics are amino ester agents? (select two)
Chloroprocaine
Cocaine
Are amino ester local anesthetics.
Chloroprocaine, tetracaine, and cocaine
Which of the following agents are capable of producing a phase I block?
Succinylcholine
A phase I block is characterized by Succinylcholine is the only drug available in the US that can produce a phase I block.
Muscle fasciculations prior to paralysis,
A lack of fade on tetanus
Train-of-four, or double-burst stimulation, and
A potentiation by acetylcholinesterase drugs.
A phase I block is characterized by Succinylcholine is the only drug available in the US that can produce a phase I block.
Muscle fasciculations prior to paralysis,
A lack of fade on tetanus
Train-of-four, or double-burst stimulation, and
A potentiation by acetylcholinesterase drugs
A phase I block is characterized by
Muscle fasciculations prior to paralysis,
A lack of fade on tetanus
Train-of-four, or double-burst stimulation, and
A potentiation by acetylcholinesterase drugs
Is the only drug available in the US that can produce a phase I block ?
Succinylcholine
3 conditions is associated with an increased risk of hyperkalemia following succinylcholine administration?
Closed head injury
Burn injury
Guillain-Barre Syndrome
Other conditions you should not give succ ? NEURO
Massive trauma, spinal cord injury, Stroke ruptured cerebral aneurysm Polyneuropathy Near drowning Myopathies
Which of the following statements concerning the metabolites of morphine is correct?
Morphine-6-glucuronide appears to exert a CNS effect that is far more potent than morphine. M6G is not lipid soluble. Despite its CNS potency, not much of it can usually cross the blood-brain barrier. After chronic administration, however, it can accumulate and begin to cross the blood-brain barrier by mass action.
Which of the following statements concerning the metabolites of morphine is correct?
Morphine-6-glucuronide appears to exert a CNS effect that is far more potent than morphine.
Inactive metabolite of morphine
Morphine-3-glucuronide is inactive.
Is M6G lipid soluble?
NO
Which of the following conditions would most likely prolong or potentiate the effects of neuromuscular blockade?
Acidosis Hypercarbia Hypothermia Hypokalemia Hypermagnesemia.
Prilocaine is metabolized to _______________, which can result in methemoglobinemia.
O-toluidine
O-toluidine, a metabolite of prilocaine MOA
oxidizes hemoglobin to methemoglobin, resulting in methemoglobinemia.
Acidosis effects on neuromuscular blockade?
Potentiates
Hypercabia effects on neuromuscular blockade?
Potentiates
Hypothermia effects on neuromuscular blockade?
Potentiates
Hypermagnesemia effects on neuromuscular blockade?
Potentiates
Which value for an inhaled anesthetic would you expect to be the highest? MAC wise
MAC-BAR
The term MAC-Awake is the concentration that produces unconsciousness in
50% of patients.
Typically, the MAC-Awake is about
half of MAC.
What is MAC-memory?
MAC-Memory is the concentration that produces amnesia in 50% of patients.
The MAC-BAR50 of both isoflurane and desflurane is
1.85 times MAC, and that’s with the addition of 60% nitrous oxide.
Which agent is a pure opioid antagonist that reverses opioid induced respiratory depression and analgesia?
Naloxone
Naloxone reverses analgesia through those receptors?
Through antagonism at mu, delta, and kappa receptors.
How does diazepam affect the CO2 response curve?
decreases the slope of the curve
Unlike most other CNS depressants, however, diazepam does not
shift the curve to the right.
Unlike most other CNS depressants, however, diazepam does not
shift the curve to the right.
The action of which of the following nondepolarizing muscle relaxants would be prolonged in the presence of liver failure? (select two)
Rocuronium
Pancuronium
A NDNMB agent that depends significantly (about 20%) on hepatic metabolism for clearance and its action is prolonged in patients with liver failure/cirrhosis.
Pancuronium
Depends upon metabolism by nonspecific esterases and is not prolonged by liver disease
Atracurium
It should also be noted that in patients with cirrhosis, the initial dose to achieve adequate muscle relaxation with pancuronium is
high and simultaneously there is slow disappearance of pancuronium from plasma.
Which of the following statements regarding respiratory gas tension and cerebral blood flow (CBF) is true?
Hypocapnia (decrease CO2 in blood) decreases cerebral blood flow. This effect usually lasts for about 4-6 hours.
PaO2 has little effect on CBF until it reaches a tension of 50 mmHg at which point it
dramatically increases CBF.
Which term describes the diversion of blood from a myocardial bed with limited or inadequate perfusion to a bed with more adequate perfusion?
Coronary steal
Explain coronary steal syndrome?
As the normal vessels dilate, blood is shunted towards the normal areas of the heart and away from the areas supplied by the already diseased vessels. This can result in worsening of ischemia.
The drugs most commonly involved in anesthesia-related allergic reactions are (select two)
Neuromuscular blocking agents
Antibiotics
Which A type fibers transmit temperature sensation and pain?
A-delta fibers transmit temperature sensation and pain.
Which of the following would explain a duration of action for succinylcholine of 6-8 hours?
Homozygous atypical pseudocholinesterase
A dibucaine number of 50 and heterozygous atypical pseudocholinesterase are also associated with a prolongation of action by
about 20-30 minutes.
Organophosphates will prolong the duration of succinylcholine
usually only by about 20-30 minutes
Homozygous atypical pseudocholinesterase occurs in 1:3200 persons and results in the production of a
pseudocholinesterase that has 1% of the normal affinity for succinylcholine. This results in greatly reduced metabolism of succinylcholine and a duration of action of 6 to 8 hours. .
How many sodium ions exit a cell for each two potassium ions that enter during repolarization?
3
What is the dibucaine number in a normal, healthy adult?
70 or higher
The dibucaine number is used to
assess the degree of pseudocholinesterase deficiency.
A normal dibucaine number is
greater than 70.
Heterozygous deficiency is defined as a dibucaine number between
30-70.
Atypical homozygous deficiency is characterized by a dibucaine number
below 30.
What is the elimination half-life of flumazenil?
60 minutes (1 hour)
Sevoflurane may need to be used with caution or possibly avoided in patients with
epilepsy; Sevoflurane can enhance seizure activity and needs to be used with caution in patients with a history of epilepsy.
Double-burst stimulation (DBS) is characterized by I.
Two short sequences of 50 Hz electrical impulses separated by 750 milliseconds.
The primary use for Double-burst stimulation (DBS) is to
detect residual blockade by a nondepolarizing neuromuscular relaxant.
Double-burst stimulation : Fade on the second burst of DBS is easier to detect than
fade on a train of four.
Tetanus consists of
repeated electrical impulses at a rapid frequency of 50, 100, or even 200 Hertz.
With Tetanus, in the case of a depolarizing block, the amplitude of the contraction is
decreased and fade is exhibited over the course of the five-second recommended duration of stimulus
A train-of-four stimulus consists of
four single pulses of equal intensity at intervals of 0.5 seconds.
With a TOF, when a partial depolarizing block is present, all four contractions will be
diminished
With a TOF, when a partial NON-depolarizing block there will be
Fade in intensity of the contraction over the course of the stimulations, with the potential absence of some or all of the contractions depending on the intensity of the block.
The use of meperidine requires caution in patients with renal failure because of the potential for
prolonged respiratory depression
Most of the commonly used opioids are inactivated by the ______and some or all of the metabolites are excreted in
liver, the urine.
With the exception of ____and _____most opioids do not result in significant prolongation.
morphine and meperidine,
The metabolites morphine-6-glucuronide and normeperidine however, are capable of exerting
clinical effects and may result in respiratory depression in patients with renal failure.
Which opioid agonist agent is the least potent?
Alfentanil
The following is a ranking of potency for the above opioid agonists: SFRA
Sufentanil>Fentanyl=Remifentanil>Alfentanil
Which drug produces a functional dissociation between the thalamocortical and limbic systems?
Ketamine
Which nerve fiber is associated with motor function?
A-alpha
Large fibers that are heavily myelinated.
A-Alpha
When administered for induction, etomidate may cause a slight decrease in blood pressure. If it occurs, this is most likely due to a decrease in
systemic vascular resistance
Etomidate administration causes minimal It is well as any other patients in whom maintenance of a normal BP is imperative.
changes in hemodynamic status.
Considered the induction drug of choice in patients with cardiovascular disease
Etomidate
Slight decreases in BP following administration of etomidate are due to a
minor decrease in SVR.
The oil:gas partition coefficient for sevoflurane is about
50
Used in patients addicted to opioids to prevent the euphoric effects of opioids
Naltrexone
are heavily myelinated, have a diameter of 12-20 microns, and are responsible for .
A-alpha fibers
Responsible for somatic motor impulses and proprioception.
A-Alpha
Moderately myelinated, have a diameter of 5-12 microns, and transmit touch and pressure impulses
A-beta fibers
Moderately myelinated, have a diameter of 3-12 microns, and transmit proprioception impulses.
A-gamma fibers
LIightly myelinated, have a diameter of <3 microns, and transmit autonomic impulses.
B fibers
Transmit pain and temperature impulses.
C fibers have a diameter of 0.3-1.3 microns
Diameter of 0.3-1.3 microns
C fibers
Which of the following conditions would most likely prolong or potentiate the effects of neuromuscular blockade?
Hypothermia
Which nerve fiber is responsible for transmitting pain, cold temperature, and touch?
. A-delta
Following injection of lidocaine during an epidural anesthetic, the patient begins to complain of numbness of her lips, dizziness, and ringing in the ears. Which of the following would be an appropriate intervention?
Encourage the patient to hyperventilate. This patient exhibits early signs of central nervous system toxicity from local anesthetics, possibly due to intravascular injection during the epidural
LAST, As the toxic symptoms progress, treatment for bradycardia and termination of seizures.
atropine may be indicated for bradycardia or sodium thiopental 50-100 mg to terminate seizures.
In the early stages of Local anesthetic toxicity , what is the treatment of choice? why?
Hyperventilation (preferably with 100% oxygen) is the treatment of choice.a
Why is hyperventilation with 100% O2 is the treatment of choice for LAST in early stages?
Hyperventilation with 100% oxygen increases the plasma pH to counteract these effects and denitrogenates the lungs in the event emergency intubation becomes necess
Acidosis worsens the toxic effects of local anesthetics by causing
cerebral vasodilation and delivering more drug to the brain, reducing plasma protein binding which leaves more free drug available in the circulatory system, and by causing ion trapping within the neuron due to increased intracellular acidosis.
Why is a Phase II block rarely seen with succinylcholine?
The doses required to produce a Phase II block are rarely administered (4-8 mg/kg)
Which of the following agents would be able to precipitate malignant hyperthermia in a susceptible patient?
All VA
The most serious effect volatile anesthetics can have on the neuromuscular system is their ability to trigger
malignant hyperthermia, an acute, uncontrolled syndrome that results in increased skeletal muscle metabolism.
MH causes accelerated ______which leads to
Increases metabolism produces increased oxygen consumption and heat production, the formation of lactate, and rhabdomyolysis.
MH Overall clinical manifestations include
tachycardia, an unexplained increase in end-tidal CO2, tachypnea, and masseter or total body rigidity.
Propofol, nitrous oxide, and ketamine and MH
are not triggers of malignant hyperthermia.
During intravenous induction, you administer 10 percent of your calculated rocuronium dose followed by your induction agent, then the rest of the rocuronium dose. This technique is known as
priming
When used for rapid sequence induction, the onset of rocuronium can be accelerated by a technique called
priming. This is achieved by giving 10% of the calculated intubating dose before the induction of anesthesia.The patient is then induced following a period of 1 to 3 minutes, and the rest of the rocuronium dose is administered.
Rocuronium when using priming dose speeds the
onset, however it can result in respiratory distress in 10% of patients.
You suspect that a patient has local anesthetic systemic toxicity from an inadvertent vascular injection. Which of the the following agents is the treatment of this condition?
. lipid emulsion therapy
As soon as signs of local anesthetic toxicity appear, you should consider
lipid emulsion therapy as it is now considered a standard part of the resuscitation of patients with LAST.
How do you dose lipid emulsion ?
The initial bolus is 1.5 mL per kilogram of a 20% lipid emulsion over 1 minute followed by a continuous infusion of 0.25 mL/kg/minute.
Medications to avoid when the patient presents with LAST?
Vasopressin, beta blockers, calcium channel blockers are to be avoided.
Which intravenous opioid has the fastest onset?
Alfentanil has an almost immediate onset when administered.
Alfentanil FASTEST speed of onset is due to
small volume of distribution, and 90 percent of the drug is in the nonionized form at physiologic pH, leading to an increased amount of drug being available for binding.
Acidosis and MAC
decreases MAC
Pregnancy and MAC
decreases MAC.
It has been demonstrated that natural redheads have
a significantly higher anesthetic requirement for desflurane than do non-redhead patients.
Vecuronium is chemically derived from what other neuromuscular blocking agent?
Pancuronium
Vecuronium was created by manipulating the
pancuronium molecule, changing it from a bisquaternary compound to a monoquaternary compound. This alteration produced a drug that has an onset time and potency that is 1.5 times greater than that of the parent drug pancuronium.
What is the usual concentration of epinephrine added to local anesthetics to prolong epidural blockade?
The usual concentration of epinephrine added to local anesthetics is 1:200,000 or 5 mcg/mL
Using a peripheral nerve stimulator with electrodes overlying the patient’s ulnar nerve, you have delivered a series of four twitches every half-second for a total of 2 seconds. Which test have you performed?
Train-of-four
The train-of-four test is comprised of a
series of four twitches applied every half-second (2 Hz stimulation) for a total of 2 seconds.
Which of the following would be added to a local anesthetic prior to injection to facilitate the spread of the drug through the tissues?
Hyaluronidase
Hyaluronidase is added to local anesthetic to facilitate the spread of the drug through the tissues. The primary use for this technique is when injecting local anesthetic into
the orbit prior to opthalmologic surgery.
Sodium bicarbonate is added to LA to
speed the onset of the drug.
Epinephrine is added to a local anesthetic to
prolong the duration of the drug.
The speed at which Hofmann elimination acts to degrade atracurium depends primarily on (select two)
pH
Temperature
Hofmann elimination is both pH and temperature dependent. When LA injected, what happens ?
the pH of the solution rises to normal body pH, the temperature rises from room temperature to body temperature, and Hofmann elimination begins.
Select two agents that may produce myoclonic-like activity.
Propofol and etomidate both produce myoclonic-like activity
Least to true epileptogenic activity?
Methohexital
You administer succinylcholine in a high dose to a patient that has a pseudocholinesterase deficiency. What results would you expect to see?
A prolonged phase 2 block
Small doses of succinylcholine in a normal patient produce a phase 1 block. High doses of succinylcholine or succinylcholine administered to patients with a pseudocholinesterase deficiency will produce a
phase 2 block.
Of the toxic central nervous system effects attributed to intravascular injection of a large volume of local anesthetic, which would likely appear first?
Tingling of the lips
The typical sequence of CNS symptoms seen from local anesthetic toxicity in order of appearance are
CiLiTiVi, SMIUGCA
Circumoral numbness
Lightheadedness
Tinnitus
Visual disturbances,
slurring of speech muscle twitching, irrational conversation, unconsciousness, grand mal seizures, coma, and apnea.
Select two opioids that cause the release of histamine from mast cells when administered in high doses.
Morphine
Meperidine
Codeine
Select two disorders where succinylcholine is avoided.
Myotonia
Muscular dystrophy
Which sedative-hypnotic agent may cause an increase in blood pressure and heart rate?
Ketamine
The duration of action of which local anesthetic would be prolonged the least by the addition of epinephrine prior to injection?
The addition of epinephrine does not significantly affect the duration of action of bupivacaine, etidocaine, or prilocaine, whereas mepivacaine and lidocaine are significantly prolonged.
Which sequence accurately describes the progression of paralysis following the administration of neuromuscular blocking agents?
Eye muscles, extremity muscles, abdominal muscles, diaphragm
Which sequence accurately describes the RETURN of paralysis following the administration of neuromuscular blocking agents?
diaphragm, abdominal muscles, extremity muscles, Eye muscles
Stimulation of GABA receptors results in an
Influx of Chloride into the cell
Gamma-aminobutyric acid (GABA) receptors are
ligand-gated ion channel receptors in the cell membrane of neurons in the central nervous system.
Which of the following agents would be most likely to produce adrenocortical suppression?
Etomidate
Side effects of etomidate.
Adrenocortical suppression
myoclonia, pain on injection, thrombophlebitis, and postoperative nausea and vomiting
Which agent is most likely to produce nausea and vomiting in adult patients?
Etomidate
Ketamine is associated with an increased incidence of ____In what patients?
nausea and vomiting in pediatric patients but not adult patients.
Which of the following IV anesthetics agents would most readily cross the placenta?
Ketamine
Ketamine and placental ?
is very lipid soluble and quickly crosses from the placenta to the fetus. Uterine blood flow is maintained as well as uterine tone.
Ketamine Induction doses of not compromise neonatal status at delivery?
0.5-1 mg/kg, however, do not compromise neonatal status at delivery.
Ketamine Induction doses that result in a depressed neonate upon delivery.
2-2.5 mg/kg
Which value for an inhaled anesthetic would you expect to be the lowest?
MAC-memory
Which of the following statements is true concerning the effect of opioids on the CO2 response curve
They shift the curve to the right, which represents a decrease in responsiveness to CO2
Which opioid agent is used mainly for the treatment of opioid abstinence syndromes, heroin addiction, and chronic pain relief?
Methadone
What are the characteristics of a phase II block from succinylcholine administration? (select two)
Posttetanic potentiation
Fade on train-of-four
Which intravenous anesthetic has the fastest elimination half-life?
Propofol has the fastest elimination with a half-life as short as 30 minutes to 1.5 hours.
Etomidate and midazolam both have an elimination half-life of
2-4 hours.
The elimination half-life of ketamine is about
2-3 hours.
Which effect on the respiratory system are you most likely to see with the administration of an inhalation anesthetic?
Respiratory depression due primarily to a decrease in tidal volume
Inhalation agents depress the
respiratory system in a dose-dependent fashion.
Inhalation agents, The tidal volume is primarily affected, followed by the respiratory rate. The tidal volume is decreased as the
concentration of the agent increases. The respiratory rate increases, but this is typically insufficient to prevent increases in arterial CO2 due to hypoventilation.
Which nerve would be most appropriate to monitor using a peripheral nerve stimulator to determine adequacy of muscle relaxation prior to intubation?
Facial nerve
Which neuromuscular blocker is contraindicated in patients with muscle denervation from CVA, spinal cord injury, or myelopathy?
Succinylcholine
Which local anesthetics will produce vasodilation (select two)
prilocaine, bupivacaine
Isoflurane has 5 fluorides, desflurane has 6, and sevoflurane is the most fluorinated with 7 fluoride atoms.
IDS (567)
Approximately 77% of cisatracurium is eliminated by
Hofmann elimination, and 23% is by nonspecific esterases.
Max dose of Neogstigmine is
0.07 mg/kg
Anticholinesterase that is a tertiary amine
Physostigmine
Which inhalational agent has a vapor pressure of about 160 mmHg?
Sevoflurane
Which agent is a pure opioid antagonist that reverses opioid induced respiratory depression and analgesia?
Naloxone
hat is the most common cause of local anesthetic systemic toxicity?
Inadvertent vascular injection
What is the drug of choice for preventing seizures in a patient with local anesthetic systemic toxicity?
Benzodiazepines
The addition of sodium bicarbonate to local anesthetics would be responsible for all of the following except:
Increase ionization
Mivacurium owes its short duration to its elimination process: it is rapidly hydrolyzed by Diseases affecting the production of this enzyme will result in a longer duration of action. I
plasma cholinesterases into two molecules of a quaternary alchohol and a dicarboxylic acid, which are then eliminated in bile and urine.
Mivacurium owes its short duration to its elimination process: it is rapidly hydrolyzed by
plasma cholinesterases into two molecules of a quaternary alchohol and a dicarboxylic acid, which are then eliminated in bile and urine.
ndividuals with atypical plasma cholinesterase should not be given mivacurium because
it could result in a significantly prolonged blockade.
Individuals with atypical plasma cholinesterase should not be given mivacurium because
it could result in a significantly prolonged blockade.
LA vasodilation except
cocaine, lidocaine, and ropivacaine.
Imagine four anesthesia gases identified as gas A, B, C, and D. Given the oil:gas partition coefficients for each gas as follows: Gas A = 78, Gas B = 5.5, Gas C = 102, and Gas D = 2.1, which anesthetic gas would you expect to be the most potent?
Gas C
The oil:gas solubility coefficient provides an indication to
the potency of an inhalation anesthetic.
The higher the oil:gas solubility, the
greater the potency.
The estimated MAC of an agent can be calculated by
dividing 150 by the oil:gas coefficient.
Place the muscle groups in the correct order in which they would become paralyzed by a non-depolarizing muscle relaxant.
Ocular , extremities, then diaphragm
Place the muscle groups in the correct order in which they would recover from paralysis by a non-depolarizing muscle relaxant.
Diaphragm, extremities, ocular
The duration of action of which local anesthetic would be prolonged the least by the addition of epinephrine prior to injection?
Bupivacaine, etidocaine and prilocaine
Which opioid receptor produces diuresis when stimulated? How?
Kappa; When stimulated, kappa receptors inhibit the release of vasopressin, resulting in diuresis.
You have just performed a train-of-four assessment on your patient using a peripheral nerve stimulator. What is the minimum amount of time you should wait before repeating the test?
12 seconds
You are preparing to induce general anesthesia with a volatile anesthetic in a patient with a left-to-right shunt. You know that this condition would
In a left-to-right shunt, the blood delivered to the lungs has a higher partial pressure of anesthetic than the blood that has passed through the tissues. As a result, a left-to-right shunt will offset the dilutional effect of a right-to-left shunt. In fact, the effect of a left-to-right shunt on the speed of induction is only detectable if a right-to-left shunt is already present. Ventricular septal defect (as may occur with tetralogy of Fallot) produces a right-to-left shunt.
Atracurium should be refrigerated because
it loses potency if not refrigerated
Atracurium refrigerated, When stored refrigerated at
5 degrees Celsius, atracurium loses potency at a rate of 6% per year, whereas when it is stored at room temperature, it loses potency at a rate of roughly 5% per month.
Atracurium recommended unrefrigerated shelf life is
14 days.
What are the major factors that determine the rate of elimination of amide local anesthetics? (select two)
Hepatic enzyme activity
Hepatic blood flow
Cisatracurium is primarily metabolized by
Hoffman
Rhabdomyolysis in a pediatric patient who has received succinylcholine is associated with undiagnosed
Duchenne’s muscular dystrophy
What are the major factors that contribute to the negative inotropic and chronotropic effects of local anesthetic toxicity? (select three)
Hypoxia
Hypercarbia
Acidosis
Which local anesthetic has the highest potency and longest duration?
Tetracaine
Both intermediate in potency and duration, while
Lidocaine and mepivacaine
Procaine has low
potency and a short duration of action.
Which local anesthetic produces vasoconstriction, shrinks the mucosa, and helps facilitate nasal surgery?
Cocaine
NDNMB and Ketamine: Ketamine will
potentiate the effects of nondepolarizing muscle relaxants, but does not prolong depolarizing blockade.
Pregnancy is associated with low levels of
pseudocholinesterase and may result in a prolonged depolarizing block.
Which neuromuscular blocking agent is best suited for a rapid sequence induction?
Rocuronium
Rocuronium intubating dose and onset
A dose between 0.6 and 1.2 mg/kg generally produces conditions suitable for intubation within 45 to 90 seconds.
Which ion channels are the most important to the initiation and propagation of an action potential?
sodium
The primary means of elimination of rocuronium is
Elimination of rocuronium is via both hepatic and renal mechanisms. Biliary elimination of unchanged drug is its primary route of elimination, however it also undergoes de-acetylation in the liver. Excretion via the kidneys represents roughly 33% of rocuronium’s elimination.
Which local anesthetic has low potency and short duration?
procaine
Which IV sedative-hypnotic agent has the highest degree of protein binding?
Propofol
Compared to nalbuphine, butorphanol exhibits (select two)
greater analgesic qualities
greater sedative effects
Regarding local anesthetics, which of the following are associated with acidosis? (select two)
Increased uptake of the local anesthetic into the brain
Increased proportion of free drug in the bloodstream
Acidosis and/or hypercarbia and seizures.
decrease the convulsive threshold of local anesthetics.
Acidosis decreases the
plasma protein binding, which increases the free form of the drug in the bloodstream which results in an increased amount available for diffusion into the brain.
Which local anesthetic only exists in a nonionized state?
benzocaine
You have just performed a train-of-four assessment on your patient using a peripheral nerve stimulator. What is the minimum amount of time you should wait before repeating the test?
12 sec
What is the most common serious complication associated with opioid intrathecal and epidural administration?
Respiratory depression
Succinylcholine recovery?
It takes 12-15 minutes on average before full neuromuscular recovery occurs.
What is the negative membrane potential of a resting peripheral nerve?
. -60 to -90 mV
Nystagmus is a common side effect of which IV anesthetics?
Ketamine
Which agent is least likely to reduce bispectral index levels?
Ketamine
Which agent can be added to increase absorption and speed the onset of a local anesthetic?
Sodium bicarbonateThe addition of sodium bicarbonate to a local anesthetic solution increases the pH of the solution, resulting in more drug in the unionized form. This increases absorption, speeds onset, and decreases the pain of infiltration
The duration of which local anesthetic is prolonged the most by the addition of the epinephrine?
Lidocaine
The potency of local anesthetics increases with:
Increased lipid solubility
Other factors that increase potency are an increased
number of carbon atoms which increases the lipid solubility, adding a halide to the aromatic ring, an ester linkage, or the presence of large alkyl groups on the tertiary amide nitrogen.
What is the main determinant of the rate at which an amide local anesthetic is metabolized?
Hepatic clearance
Which of the following is true regarding the use of ketamine in obstetric patients?
Maternal doses of 2 mg/kg produce neonatal depression
Which of the following is associated with decreased concentrations of plasma cholinesterase and a prolonged duration of action of succinylcholine?
Muscular dystrophy
Which of the following agents is an alpha-2 agonist?
Dexmedetomidine
You are preparing to perform nasal intubation for a patient undergoing dental surgery and are administering 4% cocaine intranasally to constrict the nasal passages. What is the maximum volume of the cocaine solution that can be administered?
4 ml
A patient has a known history of homozygous atypical plasma cholinesterase. Which of the following drugs should be avoided in this patient?
Mivacurium
Where in the axon do local anesthetics primarily exert their effects?
Nodes of Ranvier
The functional unit of a peripheral nerve cell is the
axon.
The myelin acts as
insulation that greatly increases the speed of electrical conduction.
The intracellular contents of the axon, known as the axoplasm, are surround by a cell membrane called the
axolemma.
Which agent should not be used in a neuraxial block?
Remifentanil
Select two opioids that cause the release of histamine from mast cells when administered in high doses.
It has a molecular weight of 200.1
It contains more fluorine atoms than desflurane
Which nerve fibers are responsible for muscle tone?
Gamma
What is the IV induction agent of choice for patients with active bronchospasm?
Ketamine
Which nerve fibers would you expect to be more resistant to the effects of local anesthetics?
Unmyelinated nerve fibers responsible for pain and temperature transmission
Respectively, what are the approximate vapor pressures (mm Hg) of desflurane and isoflurane?
660 ; 240
During intravenous induction with etomidate, the patient complains of burning in the arm with the IV. You know that this is due to
the propylene glycol preservative
Which statement is a correct summary of the Meyer-Overton rule?
Potency of an anesthetic is proportional to its lipid solubility
The metabolism of which benzodiazepine is least affected by liver disease?
Lorazepam
Ketamine exerts its CNS effects primarily by antagonizing the phencyclidine site on the ________receptor.
NDMA
Which nerve supplies the adductor pollicis muscle?
Ulnar
What is the treatment for methemoglobinemia caused by prilocaine?
Methylene blue 1-2 mg/kg
At what MAC level would you expect to first see burst suppression on the EEG with desflurane?
1.5-2.0 MAC
Lipophilic opioids penetrate faster and achieve higher concentrations in the spinal cord than hydrophilic opioids. Select the two most lipophilic opioids.
Fentanyl
Sufentanil
Which anesthetic agent is most associated with a transient increase in liver enzyme levels?
Desflurane
Which of the following benzodiazepines has the longest elimination half-life?
Diazepam has a slow hepatic extraction ratio and a large volume of distribution which is responsible for its long elimination half-life of 30-40 hours.
Which of the following is a metabolite of succinylcholine?
Succinylmonocholine
hat is the resting membrane potential of a nerve cell?
The negative membrane potential of a resting peripheral nerve is -70 to -90 mV
hat is the recommended intravenous dose of ketamine used for preemptive analgesia?
10-20mg
