SEE/NCE Anesthesia IV and Inhaled Anesthetics Flashcards
The presence of a right to left shunt will affect inhalation induction by?
Lower/decrease the arterial partial pressure of the anesthetic
How does the right to left shunt leads to a slower rate of induction?
In a right-to-left shunt, the shunted blood dilutes the blood returning from ventilated alveoli. As a result, the arterial partial pressure of the gas is reduced, and the rate of induction becomes slowed.
This slowing down of induction in a right-to-left shunt will be more pronounced in an agent with
low blood solubility than in an agent with high blood solubility. This is because the uptake of the soluble agent offsets the dilutional effect the shunt produces
Age and Intraoperative bronchospasm relationship
age less than 10 years more at risk
Airway device and bronchospasm relationship
Endotracheal intubation
How does the inhaled anesthetics affect myasthenia gravis?
Skeletal muscle relaxation In patients with myasthenia gravis is more pronounced and enhanced by as much as 40%
Skeletal muscle relaxation is most pronounced when using what kind of volatile anesthetics?
potent volatile anesthetics in excess of 1.0 MAC
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
With volatile anesthetics, how is minute ventilation affected ?
The tidal volume is primarily affected, followed by the respiratory rate.
Vt and volatile anesthetic relationship
Inverse proportional relationship –> The tidal volume is decreased as the concentration of the agent increases
What happens to the RR ? Does CO2 increase?
The respiratory rate increases, but this is typically insufficient to prevent increases in arterial CO2 due to hypoventilation
2 potential byproducts of sevoflurane administration are
Compound A
Fluoride
Compound A and sevoflurane has been associated with
Low flow anesthesia
How to remember number of fluoride between DES, SEVO and ISO
5-6-7 I-D-S 5- Isoflurane 6- Desflurane 7- Sevoflurane
The composition of the inspired gas mixture a patient receives depends primarily upon what 3 things? .
Fresh gas Flow rate
Absorption by the circuit
Volume of the breathing circuit
The best way inspired gas concentration will be closer to the fresh gas concentration
- if the circuit volume and level of absorption by the circuit are low
- the fresh gas flow is high.
A patient with a right-to-left shunt is about to undergo induction of general anesthesia. You expect that the speed of induction will be _____ and this effect would be greatest with _____.
Slower;
Greatest with the low blood/gas solubility agent like nitrous / desflurane
What is the vapor pressure of Desflurane?
660 mmHg
What is the vapor pressure of Isoflurane?
240 mmHg
How does nitrous oxide affect PVR (Pulmonary vascular resistance)
Nitrous increases PVR
You are anesthetizing a patient with a congenital heart disease and a right-to-left shunt. The use of nitrous oxide could
increase the shunt due to an increase in PVR
MAC is related to the
oil:gas solubility coefficient of an anesthetic agent.
One way to estimate the approximate MAC of an agent is to
divide 150 by the oil:gas coefficient. In this case, 150 divided by 100 would equal an estimated MAC of 1.5%.
Overpressuring during an inhalation induction is acceptable with sevoflurane because it
less pungent and less likely to produce airway irritation.
What is the definition of Overpressuring?
Overpressuring is the use of higher inspired concentrations of an inhaled anesthetic than the desired endpoint to achieve a faster induction speed. Overpressuring is acceptable with sevoflurane
Under normal conditions, the mechanism of autoregulation maintains constant cerebral blood flow over a range of mean arterial pressures from _____ to _____ mm Hg.
60-140 mmHg. (nagelhout)
As MAP decreases within the autoregulation range (60-140mmHg) what happens to cerebral vessels?
the cerebral vessels dilate to keep CBF constant.
Modern volatile anesthetics decrease the blood pressure primarily by their effect on
systemic vascular resistance
How are cortical somatosensory evoked potentials affected by the administration of volatile anesthetics?
DAIL
Decrease Amplitude
Increase Latency
Which is more pronounce with the effect of volatile anethestics on SSEPs : The decrease in amplitude or the increase in latency?
The decrease in amplitude is more pronounced than the increase in latency.
Vessel rich group receive _____% of CO?
75
Desflurane boils at ______
22.8 C which is slightly above normal room temperature.
When a volatile agent is administered, there is an initial _______in amplitude followed by a _____ in both amplitude and frequency.
increase ; decrease
At what MAC does EEG exhibit electrical silence; What is it referred to as?
At about 2.0 MAC, the EEG may temporarily exhibit electrical silence. This is referred to as burst suppression.
The concentration of inhaled anesthetic that prevents an adrenergic response to skin incision is referred to as
MAC-BAR
Adrenergic response to skin incision are
increased heart rate, blood pressure, plasma norepinephrine levels
What is the dose of volatile anesthetic that prevents the adrenergic response in 50% of patients?
MAC-BAR50
What is the dose that prevents an adrenergic response in 95% of patients.
MAC-BAR95
The blood/gas partition coefficient of isoflurane is
1.43 (some source say 1.46).
Where do anesthetics act to inhibit motor responses to noxious stimuli?
act on the spinal cord to inhibit motor responses to painful stimuli.
At 760 mmHg, the boiling point of Sevoflurane in degrees Celsius is:
58.5
Boiling point mnemonic from high to low for Desflurane, Isoflurane, Halothane, Enflurane, and Sevoflurane
HL -> SE-HID
Boiling point for Desflurane, Isoflurane, Halothane, Enflurane, and Sevoflurane
- 8 C
- 5 C
- 2 C
- 5 C
- C
Volatile anesthetics are eliminated from the body primarily by the
Alveoli (lungs)
Metabolic acidosis on MAC acute ethanol intoxication, anemia, lidocaine administration, and decreased central neurotransmitter levels may decrease MAC levels.
Decrease
Hypoxia on MAC
Decrease
Hyperthermia on MAC
Increase
Lidocaine administration on MAC
Decrease
Decreased central neurotransmitter levels on MAC levels
decrease MAC levels .
Na+ leves and osmolarity and effect on MAC
hyponatremia, hypo-osmolality, pregnancy
Acute Ethanol on MAC
Decrease MAC
Anemia on MAC
Decrease MAC
Which of the following agents is most likely to increase the systemic vascular resistance? Amount VA and nitrous
Nitrous oxide
All modern volatile anesthetics decrease the blood pressure in a dose-dependent fashion by decreasing
vascular resistance.
All modern volatile anesthetics decrease the blood pressure in a dose-dependent fashion by decreasing vascular resistance. Nitrous oxide, however,
increases the SVR by activating the sympathetic nervous system.
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
produce a higher partial pressure of anesthetic returning to the lungs
In a left-to-right shunt, the blood delivered to the lungs has a______(high or low) partial pressure of anesthetic than the blood that has passed through the tissues.
higher partial pressure
Left-to-right shunt vs right-to-left shunt>? will offset the dilutional effect of a right-to-left shunt.
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 _______ shunt.
right-to-left
Mnemonic to remember effects of right-to-left shunt OR left-to-right shunt on volatile anesthetic partial pressure
RLL (right left low)
LRH (left right High)
Which agent has the lowest blood:gas partition coefficient?
Xenon
Blood:gas partition coefficient of nitrous is
0.46
Blood:gas partition coefficient of desflurane is
0.42
Blood gas partition coefficient measured at which temperature
37C
Blood:gas partition coefficient of Isoflurane is
1.4
Blood:gas partition coefficient of Sevo is
0.6
Blood:gas partition coefficient of Volatile anesthetics : HIGH to LOW - mnemonic
Blood/GAS - I See No D*ck
Iso sevo nitrous des
Blood:gas partition coefficient of Volatile anesthetics : HIGH to LOW - Numbers
- 4
- 6
- 47
- 42
Oil:gas partition coefficient of Volatile anesthetics :HIGH to LOW - mnemonic
Oh GOD - I See De Nis Isoflurane Sevoflurane Desfluane Nitrous
Oil:gas partition coefficient of Volatile anesthetics :HIGH to LOW - numbers
99
50
18.7
1.4
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
the second-gas effect
One of the most significant concerns with the use of nitrous oxide is its ability to
to expand an air-filled space.
Expansion of nitrous with air-filled space can occur in any closed
space that contains air including the bowel, an air embolus, or even the balloon in an endotracheal tube cuff.
Nitrous oxide is contraindicated during tympanoplasty because the
pressure can build up to the point that it dislodges the graft.
Despite having a lower blood:gas solubility coefficient, the rate of rise of the FA/Fi ratio is higher for nitrous oxide than for desflurane. This is due primarily to the
concentration effect
Agents with a lower blood:gas partition coefficient exhibit a _______ (faster/slower)rate of rise in the FA/Fi ratio.
faster
Agents with a lower blood:gas partition coefficient exhibit a faster rate of rise in the FA/Fi ratio. What is one exception? and why?
The exception is that nitrous oxide will exhibit a faster rate of rise than desflurane despite the fact that it has a blood:gas partition coefficient of 0.47 and desflurane has a blood:gas partition coefficient of 0.42.The increase with nitrous oxide is due to the fact that it is administered in doses of 50-70% compared to 3-9% for desflurane. This is referred to as the concentration effect.
Which term describes the administration of a higher partial pressure of anesthetic than the alveolar concentration actually desired for the patient?
Overpressuring. Done to speed up induction
An increase in cardiac output would slow the onset of which inhalation anesthetic the most?
Isoflurane
The higher the blood:gas partition coefficient is, the more the onset will be______ (faster/slower) by an increase in cardiac output.
slowed
The partition coefficient describes the concentration ratio of a gas at equilibrium between two locations. In this example, a blood:gas partition coefficient of 0.5 means that the blood contains
half the concentration present in the alveolar gas when equilibrium is reached.
Volatile anesthetics can produce dilation of healthy coronary vessels. When diseased vessels are not able to dilate, the risk for ischemia increases as
more blood is shunted away from the diseased vessel.
Volatile anesthetics can produce dilation of healthy coronary vessels. When diseased vessels are not able to dilate, the risk for ischemia increases as more blood is shunted away from the diseased vessel. This is known as
coronary steal
Coronary steal results in the diversion of blood flow from ___________ to _______ I
from under-perfused, ischemic myocardial areas to areas with adequate perfusion.
Coronary Steal is also known as the reverse Robin Hood effect, meaning that
oxygenated blood is diverted from the poorly-perfused areas toward the areas that already have excess flow.
The three factors that affect anesthetic gas uptake are the:
BAD
Blood:gas solubility of the gas
Alveolar blood flow
Difference in partial pressure between alveolar gas and venous blood.
Does not affect rate at which the alveolar concentration of an inhaled anesthetic approaches the inspired concentration of the anesthetic
Oil:gas partition coefficient
Least appropriate gas for a patient with a potential pneumothorax?
Nitrous oxide
Nitrous oxide is ____times more soluble in the blood than _____
34: nitrogen.
Nitrous oxide being 34 times more soluble than nitrogen means that ____WHAT DOES it lead to?
Nitrous oxide can diffuse into a space faster than nitrogen can diffuse out of it into the blood. As a result, the pressure inside the space will increase and if possible, it will expand.
The administration of 75% nitrous oxide can double the size of a pneumothorax in_______ and triple it in ______
double 10 minutes and triple it in 30 minutes.
Name all The vessel-rich group consists of the.
Brain Heart Liver Kidneys Endocrine organs
Vessel rich group constitute about ____% of body weight
10%
Vessel rich group constitute 10% of BODY WEIGHT but receive about ____of cardiac output.
75%
At what MAC level would you expect to first see burst suppression on the EEG with desflurane?
1.5-2.0 MAC
Which agents are potent inhibitors of NMDA-activated currents? (select two)
Ketamine
Nitrous
Studies also have shown that ____ and _____reduced calcium movement by NMDA channels by as much as 50%.
halothane and enflurane
What is the most likely site of action for the amnestic effect of anesthetics?
Hippocampus
Sevoflurane has been shown to demonstrate late-phase cardiac preconditioning. How long would you expect this cardioprotective effect to last?
24-48 hours
Volatile anesthetics exhibit ________effects.
cardiac preconditioning
How does volatile anesthetics provide cardio protective preconditioning effect?
They appear to alter mitochondrial electron transport in myocardial cells.
It is estimated that about 30-40% of the cardioprotective effects of volatile anesthetics occurs by
reducing the overload of calcium within the cardiac cells and improving contractility.
Sevoflurane has been shown to demonstrate late preconditioning for 24-48 hours after administration. The effects begin at_____ and maximum benefit with a dose of ____
1 MAC with a dose of 1.5 MAC needed for maximum benefit.
The Ames test identifies agents that are likely to be
mutagenic or carcinogenic and is negative for isoflurane, desflurane, sevoflurane, and nitrous oxide.
Which inhaled anesthetic would you expect to increase heart rate the most in concentrations above 1.5 MAC?
desflurane
Sevoflurane can produce a mild increase in heart rate at concentrations above___, but the effect is not an pronounced as that seen with desflurane.
1.5%
Which inhalation agent is the most pungent and least appropriate for an inhalation induction?
Desflurane
Desflurane is extremely pungent and would not be appropriate for an inhalation induction because it can produce symptoms such as?
coughing, breath-holding, salivation, and laryngospasm in an awake patient.
A ventilation-perfusion deficit ____ (slows/fasten) the speed of induction. When is the effect more pronounced?
slows; The effect is greatest in agents with a low blood:gas partition coefficient. The effect may be more visible in nitrous oxide than in desflurane despite the difference in blood:gas partition coefficients because of the extremely high concentrations of nitrous oxide normally used compared to that of desflurane.
The FA:FI difference of a volatile anesthetic is (inversely/directly/ no relationship) proportional to its rate of uptake
directly proportion
The rate of induction with a volatile anesthetic is. (inversely/directly/ no relationship)________ to its rate of uptake
iniversely proportional
Volatile anesthetics produce dose-dependent ______ in uterine smooth muscle tone and ______ in uterine blood flow in parturients. he changes are mild at MAC and become significant at 1.0 MAC.
decreases, decreases
0.5 MAC ; 1 MAC
MAC and history of chronic ethanol abuse
Increase
Cyclosporine and MAC
increase
Increase catecholamines and MAC
Increase
Red hair and MAC
increase
Volatile anesthetics can provide protection against cerebral ischemia through all of the following mechanisms
Decreasing glutamate release
Increasing cerebral blood flow
Activating ATP-dependent potassium channels
In general, most patients will not awaken from general anesthesia until what percentage of the anesthetic has been eliminated?
80-90%
The elimination of the anesthetic is referred to as washout, and its primarily determined by the
solubility of the agent.
The more soluble the agent is, the greater_____to the bloodstream and tissues.
it clings;
Emergence from a poorly-soluble agent such as desflurane occurs (faster/slower)_______than a more soluble agent like isoflurane
occurs faster than a more soluble agent like isoflurane.
All of the volatile anesthetics below have been noted to increase right atrial pressure except for
Sevoflurane
Which inhalational agent has a vapor pressure of about 160 mmHg?
Sevoflurane
Sevoflurane may need to be used with caution or possibly avoided in patients with
Epilepsy
Which inhalation agent can impair methionine synthesis by interfering with vitamin B12?
Nitrous oxide
Nitrous oxide can interfere with vitamin B12 by_____? what does that lead to ?
oxidizing the cobalt atom on the vitamin. This results in impaired methionine synthesis.
The development of nitrous oxide-induced vitamin B12 impairment requires
long exposures to high concentrations of nitrous oxide and is not an issue in anesthetic environments with proper scavenging systems.
Which anesthetic agent would be taken up by the bloodstream the fastest?
Isoflurane
What happens to highly soluble agent?
Highly soluble agents are absorbed rapidly from the alveoli into the blood and the alveolar pressure drops substantially. Because of this absorption, the alveolar concentration rises much more slowly and takes a longer time to reach the inspired concentration.
As the inspired partial pressure (PI) of an inhaled anesthetic is increased, the rate at which the alveolar partial pressure increases to meet the PI increases. This is known as the
Concentration effect
The concentration effect simply states that the higher the inspired partial pressure (PI) is, the_____(faster/slower) PA approaches the PI.
the faster
The higher the inspired partial pressure of the gas, the_______ (slower/faster)the partial pressure in the alveolus will rise to match it
faster
What are the 4 major groups tissues are divided into when discussing the transfer of volatile anesthetics to the tissues? (select four)
vessel-rich group
vessel-poor group
Muscle
Fat
Which volatile anesthetic produces the least amount of coronary vasodilation?
Sevoflurane
Perfect summary of the Meyer-Overton rule?
Potency of an anesthetic is proportional to its lipid solubility
What is the molecular weight of sevoflurane?
200.1
Which rule states that the potency of an inhaled anesthetic and its oil:gas partition coefficient are directly proportional?
Meyer-Overton rule
Liebermeister’s rule states that for every Celsius degree increase in a fever, the heart rate
increases 8 beats per minute.
As the dose of an inhalation anesthetic increases, systemic vascular resistance will _____ and renal vascular resistance will _____.
decrease, increase
As the inhalation anesthetic decreases systemic blood pressure, renal vascular resistance _____to do what?
increases to maintain blood flow through the nephrons.
According to the Occupational Safety and Health Administration (OSHA), operating room personnel should not be exposed to more than how many parts per million of a halogenated agent if nitrous oxide is also used?
0.5 ppm
According to the Occupational Safety and Health Administration (OSHA), operating room personnel should not be exposed If nitrous oxide is also used, the maximum exposure to halogenated agents allowed by OSHA is 0.5 ppm. If nitrous oxide is not used, then the maximum exposure is.
2 ppm
According to the Occupational Safety and Health Administration (OSHA), operating room personnel should not be exposed : The maximum exposure to nitrous alone is
25 ppm.
Which theory proposes that anesthetics work by dissolving in the lipid bilayer of cell membranes and producing a DISRUPTION OF MEMBRANE PROTEINS
The lipid theory of anesthesia
Which anesthetic agent is metabolized by the liver to the greatest degree?
Sevoflurane (8% nagelhout)
Volatile anesthetics metabolism –>
The volatile anesthetics undergo oxidation via the cytochrome P450 pathway. Sevoflurane undergoes the greatest degree of metabolism at 8%, and only trace amount of isoflurane, desflurane, and nitrous oxide are metabolized.
Substituting a fluorine atom for the chlorine atom on the alpha-ethyl component of isoflurane will produce
DESFLURANE
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
Which is the most important factor in the rate of rise of FA/FI?
Uptake
The expected respiratory effect of an inhaled anesthetic?
Decrease in tidal volume
The minute ventilation is decreased primarily by a decrease in tidal volume due to a
decreased responsiveness to carbon dioxide.
Volatile anesthetics and response to hypercarbia/hypoxia?
All volatile anesthetics produce a dose-dependent reduction in the response to hypercarbia. They also produce a dose-dependent decrease in the response to hypoxia.
With the response to VA, The respiratory rate will_______ in response to this, but not enough to maintain the minute ventilation.
increase
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?
C
The estimated MAC of an agent can be calculated by
dividing 150 by the oil:gas coefficient
Which volatile agent increases cerebrospinal fluid absorption?
Isoflurane
Why is isoflurane special?
Isoflurane is unique in that it is the only volatile agent that facilitates CSF absorption and has a favorable effect on CSF dynamics.
Inhalation anesthetics and ICP
produce dose-dependent increases in intracranial pressure
Inhalation anesthetics produce dose-dependent increases in intracranial pressure primarily because of
increase cerebral blood flow
Volatile anesthetics are all capable of increasing intracranial pressure due to the increase in cerebral blood flow that they produce. This effect is most significant in patients who have
a space-occupying intracranial lesion.
Modern inhaled anesthetics and fluoride
produce no clinically significant levels of fluoride
Modern inhalation anesthetics are not nephrotoxic and do not produce enough fluoride to have this effect, but the FDA still recommends caution when using
sevoflurane in patients with a serum creatinine greater than 1.5 mg/dL.
Which Inhaled anesthetic has the least effect on renal lab values ?
Desflurane is that the inhalation anesthetic that has the least effect on renal laboratory values.
All other factors being equal, which inhalation agent would exhibit the fastest emergence?
Desflurane
Sevoflurane may be less likely to result in an increase in intracranial pressure than desflurane upon emergence because it is
Less pungent. Sevoflurane may have an advantage over desflurane in patients at risk for injury due to increases in ICP. Because of its lower pungency, it produces less of a risk of coughing or bucking that increases ICP to dangerous levels.
Which inhalation anesthetic possesses a blood-gas partition coefficient of 0.42?
Desflurane
A change in alveolar ventilation would affect which inhalation agent to the greatest degree?
Isoflurane
Prolonged administration of nitrous oxide can produce megaloblastic changes in bone marrow due to interference in the activity of
vitamin B12-dependent enzymes
How are cerebral metabolic rate (CMRO2) and cerebral blood flow (CBF) altered by isoflurane?
A decrease in CMRO2 with an increase in CBF
You are inducing a patient undergoing surgery for an intracranial mass. What intervention would most help keep the intracranial pressure from increasing?
Desflurane 0.8 MAC or less
Can offset increase in intracranial pressure (hypoventilation/hyperventilation)
Hyperventilation to produce a PaCO2 of 30 mmHg
In the setting of hypocapnia, patients undergoing desflurane anesthesia at 0.8 MAC or less and ICP? At which MAC does that change?
do not exhibit an increase in intracranial pressure, but at 1.1 MAC, the pressure increases by about 7 mmHg.
Which of the following agents would produce the least amount of skeletal muscle relaxation?
Nitrous oxide
At 1.5 MAC, which agent would maintain cerebral autoregulation more effectively?
Sevoflurane
Which inhalational agent has no adverse effects on cerebral physiology at normal CO2 and blood pressure?
Sevoflurane
Just like the speed of induction, the recovery from inhalation anesthesia is dependent upon what 3 factors?
Solubility of the anesthetic
Cardiac output
Minute ventilation
CO , Solubility and MV and emergence , What would favor a faster emergence?
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 what happens with emergence?
can’t under-pressurize at emergence simply because you can’t reduce the inspired anesthetic below zero.
Which value for an inhaled anesthetic would you expect to be the lowest? (MAC bar, MAC awake, MAC memory, and MAC)
MAC-MEMORY
MAC-Memory is the
concentration that produces amnesia in 50% of patients.
Which anesthetic agent is most associated with a transient increase in liver enzyme levels?
Desflurane
Spontaneous ventilation will ______ the uptake of inhalation anesthetics by ________ alveolar ventilation.
Decrease; Decrease
Volatile anesthetics exert a negative feedback loop that ________their uptake in spontaneously ventilating patients.
decreases
As the patient becomes more anesthetized, alveolar ventilation decreases, which decreases the amount of anesthetic they inhale. The use of mechanical ventilation
bypasses this feedback loop.
Factors that increase the production of compound A include
Increased inspired sevoflurane concentration
Higher absorbent temperatures
Decreased water content in the absorbent
Lower fresh gas flow rates.
The administration of isoflurane 1.5% has been shown to
134.
maintain total hepatic blood flow and hepatic artery blood flow while increasing portal vein blood flow.
The use of isoflurane 1% and nitrous oxide has been shown to increase both
hepatic blood flow and hepatic oxygen extraction.
Which volatile agent doesn’t decrease the cerebral metabolic rate?
Nitrous oxide
Isoflurane, desflurane, and sevoflurane are able to _______cerebral metabolic oxygen requirements to an equal degree.
decrease
Which of the following agents has been shown to increase intracranial pressure?
Desflurane
How does Desflurane increase ICP?
BY altering the CSF flow dynamics
What 2 factors have the greatest effect on the composition of the inspired gas mixture a patient receives? (select two)
Vaporizer dial setting
Fresh gas flow rate
Sevoflurane undergoes how much metabolism?
About 5-8 % of sevoflurane undergoes metabolism.
Isoflurane and nitrous oxide undergoes how much metabolism
Less than 1%
Desflurane undergoes how much metabolism?
less than 0.1% metabolism.
The intubating dose of succinylcholine for a healthy adult is
1-1.5 mg/kg.
With succinylcholine,on average how long does it take before full neuromuscular recovery occurs.
It takes 12-15 minutes
Which agent can prolong the effect of succinylcholine? and why?
Metoclopramide ; inhibits plasma cholinesterase and prolongs the duration of succinylcholine.
Anticholinergics Antisialogogue : Greatest to least
Scopolamine>Glycopyrrolate>Atropine
Anticholinergics Increased Heart Rate:
Atropine>Glycopyrrolate>Scopolamine,
Anticholinergics Sedation:
Scopolamine>Atropine>Glycopyrrolate
Aside from adrenocortical suppression , side effects of etomidate include (3)
myoclonia
pain on injection
postoperative nausea and vomiting
Thromphlebitis with this IV induction agents
Etomidate
You administer succinylcholine in a high dose to a patient that has a pseudocholinesterase deficiency. What results would you expect to see?
Prolonged phase 2 block
You administer succinylcholine in a regular dose to a patient that has a pseudocholinesterase deficiency. What results would you expect to see?
Prolonged phase 1 block
Ketamine on ICP, CBF and CRMO2
increases intracranial pressure, cerebral blood flow, and cerebral oxygen consumption.
Ketamine on bronchioles
produces bronchodilation, not an increase in bronchiolar smooth muscle tone.
A 60 kg patient exhibits laryngospasm in the postanesthesia care unit that is unresponsive to positive pressure. The IV access has infiltrated. You decide to administer succinylcholine intramuscularly. What would the appropriate dose be? Calculate your answer to the nearest whole number in milligrams.
240 mg.
Laryngospasm that is unresponsive to positive pressure ventilation can be treated with IV such dose? IM dose ?
0.15-0.5 mg/kg succinylcholine IV or 4 mg/kg IM.
Intravenous fentanyl has an onset of
2-5 minutes
Intravenous fentanyl has an onset of
2-5 minutes
Intravenous fentanyl it has a relatively long half-life of
8 hours
Peak effect of IV fentanyl is
peak effect of 3-5 minutes
Effect of fentanyl is primarily by
redistribution away from the central nervous system.
Select two treatments for an inadvertent intra-arterial injection of thiobarbiturates.
-treated immediately with intra-arterial papaverine. Heparinization as well as a sympathectomy induced by a regional anesthetic block should also be employed.
Lipophilic opioids vs hydrophilic in the spinal cord.
penetrate faster and achieve higher concentrations in the spinal cord than hydrophilic opioids.
Select the two most lipophilic opioids.
Fentanyl
Sufentanil
Which of the following anesthetic agents would be most likely to produce delayed-onset malignant hyperthermia in a susceptible patient? (select two)
Sevoflurane
Desflurane
This drug reduces the risk of sudden cardiac death by 29% in patients with congestive heart failure. Therefore, it is the best alternative for patients who refuse or are not candidates for an AICD.
Amiodarone
Loop diuretic associated with decreased serum potassium levels.
Bumetanide
Desflurane, isoflurane, and sevoflurane all produce an increase in heart rate. At concentrations higher than 1.5 MAC, _____produces the greatest increase in heart rate.
desflurane
